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Wednesday, December 17, 2003 (DOY 344/19:00:00 to DOY 351/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2590 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1715 days
Total Mapping Orbits = 21,345
Total Orbits = 23,028

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm326 sequence has performed well since it started on 03-344 (12/10/03). It terminates near the end of day on 03-351 (12/17/03). The mm327 sequence, successfully uplinked on 03-350 (12/16/03), begins executing near the end of 03-351 (12/17/03).

Other – On 03-344 (12/10/03), the solar array offset angles were commanded from 35 degrees to 25 degrees to increase the excess energy being produced as MGS gets farther from the sun. The HGA cable heaters were powered off on 03-350 (12/16/03), also to increase power margins.

Eight Roll Only Targeted Observations (ROTOs) and one of three CPROTOs were performed successfully by the mz333, mz334 & mz335 mini-sequences. CPROTOs are ROTOs that maneuver the spacecraft to Compensate in Pitch and Roll for relative target movement induced by spacecraft AND planetary motion. PROTOs also make attitude adjustments in pitch and roll, but don’t compensate for planetary rotation. CPROTOs & PROTOs allow the Mars Orbiter Camera (MOC) to take higher resolution images of ground targets. One of this week’s CPROTOs missed its target because of spacecraft attitude errors caused by star processing difficulties following the previous ROTO. The reason why MGS missed its target on the second CPROTO is still being investigated. MGS has successfully completed 943 ROTOs to date. This number includes all flavors of ROTOs: ROTOs, PROTOs, & CPROTOs. I also added the three successful PROTO demos from earlier in the year.

Spacecraft Health:

Spacecraft subsystems report good health and performance.

Uplinks:

There were 30 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz333 & mz335 ROTO mini-sequences, the mz334 & mz336 CPROTO mini-sequences, a command to change HGA positioning for spacecraft momentum management, updates to the solar array scripts, commands to power off the HGA cable heaters, and the mm327 background sequence. 8,250 command files have been radiated to the spacecraft since launch.

Upcoming Events:

CPROTOs are planned for the mz336 & mz337 mini-sequences.

The HGA damper heaters will be powered off next week to further increase power margins before the Mars Relay (MR) instrument is turned on and for the next MGS aphelion in August 2004.

MER-A (Spirit) Entry Descent and Landing (EDL) on 04-004 (1/04/04).


Wednesday, December 10, 2003 (DOY 337/19:00:00 to DOY 344/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2583 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1708 days
Total Mapping Orbits = 21,259
Total Orbits = 22,942

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm325 sequence has performed well since it started on 03-337 (12/03/03). It terminates near the end of day on 03-344 (12/10/03). The mm326 sequence, successfully uplinked on 03-342 (12/08/03), begins executing near the end of 03-344 (12/10/03).

Other – A MOC reboot test was successfully conducted on 03-338 (12/04/03) to prepare for MER support in January.

Thirteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz330, mz331 & mz332 mini-sequences. MGS has completed 934 ROTOs to date.

Uplinks:

There were 7 uplinks to the spacecraft during the past week. They included the mz332 ROTO mini-sequence, a command to change HGA positioning for spacecraft momentum management, and the mm326 background sequence. 8,220 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz333 & mz334 mini-sequences.

On 03-344 (12/10/03), the solar array offset angles will be adjusted from 35 degrees to 25 degrees to increase the excess energy being produced as MGS gets farther from the sun. The HGA cable and damper heaters will be powered off in the next few weeks to increase power margins when the Mars Relay (MR) instrument is turned on for MER support and for the next MGS aphelion in August 2004.

MER-A (Spirit) Entry Descent and Landing (EDL) on 04-004 (1/04/04).


Wednesday, December 03, 2003 (DOY 330/19:00:00 to DOY 337/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2576 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1701 days
Total Mapping Orbits = 21,174
Total Orbits = 22,857

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm324 sequence has performed well since it started on 03-330 (11/26/03). It terminates near the end of day on 03-337 (12/03/03). The mm325 sequence, successfully uplinked early on 03-337 (12/03/03), begins executing near the end of the same day.

Other – Twelve Roll Only Targeted Observations (ROTOs) were performed successfully by the mz328, mz329 & mz330 mini-sequences. MGS has completed 921 ROTOs to date.

Uplinks:

There were 19 uplinks to the spacecraft during the past week. They included the mz330 & mz331 ROTO mini-sequences, a command to change HGA positioning for spacecraft momentum management, and the mm325 background sequence. 8,213 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz330, mz331, & mz332 mini-sequences. A MOC reboot test will be conducted on 03-338 (12/04/03) to prepare for MER support in January.


Wednesday, November 26, 2003 (DOY 323/19:00:00 to DOY 330/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2569 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1694 days
Total Mapping Orbits = 21,088
Total Orbits = 22,771

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm323 sequence has performed well since it started on 03-323 (11/19/03). It terminates near the end of day on 03-330 (11/26/03). The mm324 sequence, successfully uplinked early on 03-330 (11/26/03), begins executing near the end of the same day.

Other – The MGS STAREX Star Identification Software (SIS) had some difficulty processing stars following a ROTO on 03-329 (11/25/03). Flight software reacted appropriately, preventing MGS from entering C-mode. The “Go Nadir on SIS Reset” flight software routine was triggered at 19:34:29 SCET UTC to autonomously point the MGS z-axis to nadir. This allowed the Mars Horizon Sensor Assembly (MHSA) to stabilize the MGS attitude while STAREX regained its ability to correctly process stars. This all happened during a scheduled non-communications period. The spacecraft team noticed the nadir attitude at the beginning of the next communications pass, verified spacecraft health, and commanded MGS back to its nominal attitude at 22:53:24 SCET UTC.

Fifteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz327, & mz328 mini-sequences. MGS has completed 909 ROTOs to date.

Uplinks:

There were 22 uplinks to the spacecraft during the past week. They included the mz328 & mz329 ROTO mini-sequences, a command to change HGA positioning for spacecraft momentum management, a command file to return from nadir to the nominal attitude, and the mm324 background sequence. 8,194 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz328, mz329, & mz330 mini-sequences. A MOC reboot test will be conducted on 03-338 (12/04/03) to prepare for MER support in January.


Wednesday, November 19, 2003 (DOY 316/19:00:00 to DOY 323/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2562 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1687 days
Total Mapping Orbits = 21,003
Total Orbits = 22,686

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm322 sequence has performed well since it started on 03-316 (11/12/03). It terminates near the end of day on 03-323 (11/19/03). The mm323 sequence, successfully uplinked early on 03-322 (11/18/03), begins executing near the end of the same day.

Angular Momentum Management – The spacecraft team, in coordination with MGS Navigation, has successfully transitioned to a method for managing the Y-component of angular momentum by use of real time commands of the HGA target angles for non-comm periods.

Other – Thirteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz325, & mz326 mini-sequences. MGS has completed 894 ROTOs to date.

Uplinks:

There were eleven uplinks to the spacecraft during the past week. They included mz326 & mz327 ROTO mini-sequences, a SCP2 MRO, a command to change the HGA target angles for the purpose of momentum management, and the mm323 background sequence. 8,172 command files have been radiated to the spacecraft since launch.

Upcoming Events:

Star Cat and Ephemeris files are scheduled for uplink on day 323. ROTOs are planned for the mz328 & mz328 mini-sequences.


Wednesday, November 12, 2003 (DOY 309/19:00:00 to DOY 316/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2562 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1687 days
Total Mapping Orbits = 20,917
Total Orbits = 22,600

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm321 sequence has performed well since it started on 03-309 (11/05/03). It terminates near the end of day on 03-316 (11/12/03). The mm322 sequence, successfully uplinked early on 03-316 (11/12/03), begins executing near the end of the same day.

Other – Thirteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz322, mz323, & mz324 mini-sequences. MGS has completed 881 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance. SCP-2, the backup processor, was successfully recovered from Contingency Mode on 03-309 (11/05/03).

Uplinks:

There were 25 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, SCP-2 recovery commands, the mz324 & mz325 ROTO mini-sequences, and the mm322 background sequence. 8,161 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz325 & mz326 mini-sequences.


Wednesday, November 5, 2003 (DOY 302/19:00:00 to DOY 309/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2555 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1680 days
Total Mapping Orbits = 20,832
Total Orbits = 22,515

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm320 sequence has performed well since it started on 03-302 (10/29/03). It terminates near the end of day on 03-309 (11/05/03). The mm321 sequence, successfully uplinked early on 03-309 (11/05/03), begins executing near the end of the same day.

Other – Six Roll Only Targeted Observations (ROTOs) were performed successfully by the mz320, mz321, & mz322 mini-sequences. Two CPROTO imaging demonstrations were successfully conducted on 03-305 (11/01/03) and 03-306 (11/02/03) in the mz321 mini-sequence. CPROTO stands for Compensation Pitch and Roll Only Targeted Observation since it compensates for both planetary rotation and spacecraft motion. Imaging results from those demonstrations are pending. MGS has completed 868 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). This configuration does not threaten the spacecraft. Commands were uplinked early this morning, 03-309 (11/05/03), to recover SCP-2 back to its normal state. The commands will execute today, approximately 1.5 hours before the mm321 background sequence starts.

Uplinks:

There were 23 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, SCP-2 recovery commands, commands to demonstrate compatibility between MGS and the New Norcia tracking station, the mz321 CPROTO minisequence, the mz322 & mz323 ROTO mini-sequences, and the mm321 background sequence. 8,136 command files have been radiated to the spacecraft since launch.

Upcoming Events:

SCP-2 C-mode recovery will occur later today, 03-309 (11/05/03). ROTOs are planned for the mz323 & mz324 mini-sequences.


Wednesday, October 29, 2003 (DOY 295/19:00:00 to DOY 302/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2548 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1673 days
Total Mapping Orbits = 20,746
Total Orbits = 22,429

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm319 sequence has performed well since it started on 03-295 (10/22/03). It terminates near the end of day on 03-302 (10/29/03). The mm320 sequence, successfully uplinked early on 03-302 (10/29/03), begins executing near the end of the same day.

Other – Four Roll Only Targeted Observations (ROTOs) were performed successfully by the mz319 mini-sequence. MGS has completed 862 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). This configuration does not threaten the spacecraft. The target date for SCP-2 C-mode recovery date is 03-309 (11/05/03).

MGS health and performance has not been adversely affected by the recent solar storm activity.

Uplinks:

There were 16 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz319 & mz320 ROTO mini-sequences, and the mm320 background sequence. 8,113 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz320 mini-sequence. CPROTO imaging demonstrations will be conducted on 03-305 (11/01/03) and 03-306 (11/02/03) in the mz321 mini-sequence. CPROTO stands for Compensation Pitch and Roll Only Targeted Observation since it compensates for both planetary rotation and spacecraft motion.

SCP-2 C-mode recovery is scheduled for 03-309 (11/05/03).


Wednesday, October 22, 2003 (DOY 288/19:00:00 to DOY 295/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2541 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1666 days
Total Mapping Orbits = 20,660
Total Orbits = 22,343

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm318 sequence caused us some concern when it started on 03-288 (10/15/03). We had no downlink during the first four orbits, which were scheduled as playback orbits. Unfortunately due to a subtle sequence boundary condition, the ground software that creates the command files rejected the commands for the first four orbits. The ground software that produces the human readable representation of the command file contained the desired commands. So, the anomalous condition was not caught in the review cycle. The command sequence build processes have been updated to detect this problem if it happens again. The mm318 sequence has performed nominally from the fifth orbit to present. It terminates near the end of day on 03-295 (10/22/03). The mm319 sequence, successfully uplinked on 03-294 (10/21/03), begins executing near the end of day on 03-295 (10/22/03).

Other – Six of nine Roll Only Targeted Observations (ROTOs) were performed successfully by the mz317 & mz318 mini-sequences. The first three ROTOs of mz318 were missed because the file was not uplinked when originally scheduled. A newly certified ACE overlooked the command authorization form. A revised file was quickly built and uplinked in time to preserve the fourth and final ROTO of the mz318 mini-sequence. MGS has completed 858 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). This configuration does not threaten the spacecraft. The recovery date has slipped from 03-302 (10/29/03) to 03-309 (11/05/03) to accommodate a special MOC imaging demonstration on or about 03-305 (11/01/03).

Uplinks:

There were 19 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, transmitter-on and TWTA filament off commands, the mz317 & mz318 ROTO mini-sequences, and the mm319 background sequence. 8,097 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz319 mini-sequence. A CPROTO imaging demo will be conducted on or about 11/01/03. CPROTO stands for Compensation Pitch and Roll Only Targeted Observation since it compensates for both planetary rotation and spacecraft motion.


Wednesday, October 15, 2003 (DOY 281/19:00:00 to DOY 288/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2534 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1659 days
Total Mapping Orbits = 20,575
Total Orbits = 22,258

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm317 sequence has performed well since it started on 03-281 (10/08/03). It terminates near the end of day on 03-288 (10/15/03). The mm318 sequence, successfully uplinked on 03-287 (10/14/03), begins executing near the end of day on 03-288 (1015/03).

Other – Thirteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz315 & mz316 mini-sequences. MGS has completed 852 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). This configuration does not threaten the spacecraft and the spacecraft team is targeting 03-302 (10/29/03) to recover from C-mode on SCP-2.

Uplinks:

There were 11 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, a solar array motion script update, the mz316 ROTO mini-sequence, and the mm318 background sequence. 8,078 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz317 & mz318 mini-sequences.


Wednesday, October 8, 2003 (DOY 274/19:00:00 to DOY 281/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2527 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1652 days
Total Mapping Orbits = 20,489
Total Orbits = 22,172

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm316 sequence has performed well since it started on 03-274 (10/01/03). It terminates near the end of day on 03-281 (10/08/03). The mm317 sequence, successfully uplinked on 03-281 (10/08/03), begins executing near the end of day on 03-281 (10/08/03).

Other – On 03-276 (10/03/03), MGS successfully performed Orbit Synchronization Maneuver #1 (OSM-1) to start positioning itself to support the Mars Exploration Rovers in January 2004. Performance errors were very small: within one-tenth of a percent in magnitude and four-tenths of a degree in direction of the desired burn vector.

Four Roll Only Targeted Observations (ROTOs) were performed successfully by the mz314 mini-sequence. MGS has completed 839 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is developing a plan to recover from C-mode on SCP-2 without affecting normal SCP-1 activities.

On 03-280 (10/7/03), STAREX had difficulty processing stars following the last ROTO in mz314. The “Go Nadir” fault protection response triggered, allowing STAREX to reinitialize successfully without going into C-mode. The SCT subsequently recovered the spacecraft to its nominal Relay-16 attitude. No data was lost. The SCT is analyzing the star processing data to determine which star(s) caused the problem.

Uplinks:

There were 24 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz313 OSM-1 mini-sequence, the mz314 & mz315 ROTO mini-sequences, the “go nadir” recovery command file, and the mm317 background sequence. 8,067 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz315 & mz316 mini-sequences.


Wednesday, October 1, 2003 (DOY 267/19:00:00 to DOY 274/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2520 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1645 days
Total Mapping Orbits = 20,403
Total Orbits = 22,086

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm315 sequence has performed well since it started on 03-267 (9/24/03). It terminates near the end of day on 03-274 (10/01/03). The mm316 sequence, successfully uplinked on 03-273 (9/30/03), begins executing near the end of day on 03-274 (10/01/03).

Other – MGS performed a couple of high rate gyro bias calibrations on 03-268 (9/25/03) and 03-269 (9/26/03) to prepare for the upcoming Orbit Synchronization Maneuver (OSM).

Six Roll Only Targeted Observations (ROTOs) were performed successfully by the mz312 mini-sequence. MGS has completed 835 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities. Recovery plans will solidify in the next few weeks, following execution of the OSM.

On 03-269 (9/26/03), a PDS internal software reset temporarily corrupted the engineering data telemetry stream. The SCT sent commands to perform an external PDS reset, which quickly returned the engineering telemetry back to normal.

Uplinks:

There were 15 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, commands to calibrate the high rate gyro biases, commands to perform an external PDS reset, and the mm316 background sequence. 8,043 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz314 mini-sequence. On 03-276 (10/03/03), MGS will perform an OSM to start positioning itself to support the Mars Exploration Rovers in January 2004.


Wednesday, September 24, 2003 (DOY 260/19:00:00 to DOY 267/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2513 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1638 days
Total Mapping Orbits = 20,318
Total Orbits = 22,001

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm314 sequence has performed well since it started on 03-260 (9/17/03). It terminates near the end of day on 03-267 (9/24/03). The mm315 sequence, successfully uplinked on 03-266 (9/23/03), begins executing near the end of day on 03-267 (9/24/03).

Other – Ten Roll Only Targeted Observations (ROTOs) were performed successfully by the mz310, & mz311 mini-sequences. MGS has completed 829 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities. Recovery plans will solidify in the next few weeks, following execution of the Orbit Synchronization Maneuver (OSM).

Uplinks:

There were 24 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz310, mz311 & mz312 ROTO mini-sequences, and the mm315 background sequence. 8,028 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz312 mini-sequence. On 03-276 (10/03/03), MGS will perform an OSM to start positioning itself to support the Mars Exploration Rovers in January 2004.


Wednesday, September 17, 2003 (DOY 253/19:00:00 to DOY 260/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2506 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1631 days
Total Mapping Orbits = 20,232
Total Orbits = 21,915

Recent Events:

Background Sequences – MGS successfully transitioned from beta-supplement operations to nominal mapping operations on 03-254 (9/11/03). During nominal mapping operations, the MGS High Gain Antenna (HGA) can auto-track the Earth without impacting the HGA boom, as it was originally designed.

The spacecraft is operating nominally in performing the daily recording and transmission of science data. The mm313 sequence has performed well since it started on 03-253 (9/10/03). It terminates near the end of day on 03-260 (9/17/03). The mm314 sequence, successfully uplinked on 03-259 (9/16/03), begins executing near the end of day on 03-260 (9/17/03).

Other – Seven Roll Only Targeted Observations (ROTOs) were performed successfully by the mz308, & mz309 mini-sequences. MGS has completed 819 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities. Recovery plans will solidify in the next few weeks.

Uplinks:

There were 14 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz308 & mz309 ROTO mini-sequences, and the mm314 background sequence. 8,004 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz310 and mz311 mini-sequences. On 03-276 (10/03/03), MGS will perform an Orbit Synchronization Maneuver (OSM) to start positioning itself to support the Mars Exploration Rovers in January 2004.


Wednesday, September 10, 2003 (DOY 246/19:00:00 to DOY 253/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2499 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1624 days
Total Mapping Orbits = 20,146
Total Orbits = 21,829

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm311 sequence executed successfully from 03-247 (9/04/03) through 03-249 (9/06/03). The mm312 sequence has performed well since it started on 03-250 (9/07/03). It terminates on 03-253 (9/10/03). The mm313 sequence, successfully uplinked on 03-252 (9/09/03), begins executing near the end of day on 03-253 (9/10/03).

Other – Fifteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz305, mz306, & mz307 mini-sequences. MGS has completed 812 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities. The recovery will take place within a few weeks after MGS transitions from beta-supplement to nominal mapping operations.

Uplinks:

There were 16 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz306 & mz307 ROTO mini-sequences, and the mm312 & mm313 background sequences. 7,990 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz308 and mz309 mini-sequences. MGS will transition from beta-supplement operations to nominal mapping operations on 03-254 (9/11/03). On this date, planetary and orbital geometry will allow the MGS HGA to auto-track the Earth without impacting the HGA boom. On 03-276 (10/03/03), MGS will perform an Orbit Synchronization Maneuver (OSM) to start positioning itself to support the Mars Exploration Rovers in January 2004.


Wednesday, September 3, 2003 (DOY 239/19:00:00 to DOY 246/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2492 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1617 days
Total Mapping Orbits = 20,061
Total Orbits = 21,744

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm309 sequence executed successfully from 03-240 (8/28/03) through 03-242 (8/30/03). The mm310 sequence has performed well since it started on 03-243 (8/31/03). It terminates on 03-246 (9/03/03). The mm311 sequence, successfully uplinked on 03-245 (9/02/03), begins executing near the end of day on 03-246 (9/03/03).

Other – The Mars Relay instrument UHF experiment with Stanford University that began on 03-238 (8/26/03) was completed on 03-241 (8/29/03). Preliminary results indicate that the experiment was sucessful.

Fourteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz304 and mz305 mini-sequences. MGS has completed 797 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities. The recovery will take place within a few weeks after MGS transitions from beta-supplement to nominal mapping operations.

Uplinks:

There were 8 uplinks to the spacecraft during the past week. They included nominal instrument command loads, the mz305 ROTO mini-sequence, and the mm310 & mm311 background sequences. 7,974 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz306 and mz307 mini-sequences. MGS will transition from beta-supplement operations to nominal mapping operations on 03-254 (9/11/03). On this date, planetary and orbital geometry will allow the MGS HGA to auto-track the Earth without impacting the HGA boom.


Wednesday, August 27, 2003 (DOY 232/19:00:00 to DOY 239/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2485 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1610 days
Total Mapping Orbits = 19,975
Total Orbits = 21,658

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm307 sequence executed successfully from 03-233 (8/21/03) through 03-235 (8/23/03). The mm308 sequence has performed well since it started on 03-236 (8/24/03). It terminates on 03-239 (8/27/03). The mm309 sequence, successfully uplinked early on 03-239 (8/27/03), begins executing near the end of day on 03-239 (8/27/03).

Other – A Mars Relay instrument UHF experiment with Stanford University began on 03-238 (8/26/03) and will continue until 03-241 (8/29/03). The experiment seems to be progressing nominally.

Fourteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz302 and mz303 mini-sequences. MGS has completed 783 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities. The recovery will take place after MGS transitions from beta-supplement to nominal mapping operations.

Uplinks:

There were 16 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz303 & mz304 ROTO mini-sequences, and the mm308 & mm309 background sequences. 7,966 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz304 and mz305 mini-sequences. MGS will transition from beta-supplement operations to nominal mapping operations on 03-254 (9/11/03). On this date, planetary and orbital geometry will allow the MGS HGA to auto-track the Earth without impacting the HGA boom.


Wednesday, August 20, 2003 (DOY 225/19:00:00 to DOY 232/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2478 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1603 days
Total Mapping Orbits = 19,889
Total Orbits = 21,572

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm305 sequence executed successfully from 03-226 (8/14/03) through 03-228 (8/16/03). The mm306 sequence has performed well since it started on 03-229 (8/17/03). It terminates on 03-232 (8/20/03). The mm307 sequence, successfully uplinked early on 03-231 (8/19/03), begins executing near the end of day on 03-232 (8/20/03).

Other – MGS successfully performed six Radio Science Occultation Egress Scans on 03-229 (8/17/03) and 03-230 (8/19/03) in the mz300 mini-sequence.

Ten Roll Only Targeted Observations (ROTOs) were performed successfully by the mz299 and mz301 mini-sequences. MGS has completed 769 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, remains in Contingency mode (C-mode). While this configuration does not threaten the spacecraft, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities.

Uplinks:

There were 17 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz300 Radio Science Occultation Egress Scan mini-sequence, the mz301 & mz302 ROTO mini-sequences, and the mm306 & mm307 background sequences. 7,950 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz302 and mz303 mini-sequences. MGS will transition from Beta-supplement operations to nominal mapping operations on 03-254 (9/11/03). On this date, planetary and orbital geometry will allow the MGS HGA to auto-track the Earth without impacting the HGA boom.


Wednesday, August 13, 2003 (DOY 218/19:00:00 to DOY 225/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2471 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1596 days
Total Mapping Orbits = 19,804
Total Orbits = 21,487

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm303 sequence executed successfully from 03-219 (8/07/03) through 03-221 (8/09/03). The mm304 sequence has performed well since it started on 03-222 (8/10/03). It terminates on 03-225 (8/13/03). The mm305 sequence, successfully uplinked early on 03-225 (8/13/03), begins executing near the end of day on 03-225 (8/13/03).

Other – mz297 was used to briefly transition the downlink telemetry to engineering mode. The additional engineering telemetry along with several memory readouts provided increased visibility into the status of the backup processor.

Fifteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz296 and mz298 mini-sequences. MGS has completed 759 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance on the primary processor, SCP-1. SCP-2, the backup processor, is in Contingency mode (C-mode). SCP-2 entered C-mode because it had more difficulty processing stars than SCP-1. Because SCP-2 is not in control, there is no adverse impact to the spacecraft. If MGS were to swap processors for any reason, the spacecraft would re-enter C-mode and the spacecraft team would recover MGS using well-established procedures. In the mean time, the spacecraft team is investigating methods of recovering from C-mode on SCP-2 without affecting normal SCP-1 activities.

Uplinks:

There were 23 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, several memory readout commands, the mz297 mini-sequence to briefly go to engineering mode, the mz298 & mz299 ROTO mini-sequences, and the mm304 & mm305 background sequences. 7,9330 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz299 and mz301 mini-sequences. The mz300 mini-sequence will perform Radio Science Occultation Egress Scans on 03-229 (8/17/03) and 03-230 (8/19/03).


Wednesday, August 6, 2003 (DOY 211/19:00:00 to DOY 218/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2464 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1589 days
Total Mapping Orbits = 19,718
Total Orbits = 21,401

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm301 sequence executed successfully from 03-212 (7/31/03) through 03-214 (8/02/03). The mm302 sequence has performed well since it started on 03-215 (8/03/03). It terminates on 03-218 (8/06/03). The mm303 sequence, successfully uplinked on 03-217 (8/0503), begins executing near the end of day on 03-218 (8/06/03).

Other – On 03-213 (8/01/03), MGS performed an Image Motion Compensation (IMC) experiment in the mz294 mini-sequence. A higher slew rate was commanded than ever previously used for MOC imaging. Results are pending.

Six Roll Only Targeted Observations (ROTOs) were performed successfully by the mz293 and mz295 mini-sequences. MGS has completed 744 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance.

Uplinks:

There were 24 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz294 IMC mini-sequence, the mz295 & mz296 ROTO mini-sequences, and the mm302 & mm303 background sequences. 7,910 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz296 and mz298 mini-sequences. mz297 will be used to briefly transmit telemetry not seen on a regular basis. Radio Science Occultation Egress Scans are scheduled for 03-229 (8/17/03) and 03-230 (8/19/03).


Wednesday, July 30, 2003 (DOY 211/19:00:00 to DOY 218/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2464 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1589 days
Total Mapping Orbits = 19,718
Total Orbits = 21,401

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm301 sequence executed successfully from 03-212 (7/31/03) through 03-214 (8/02/03). The mm302 sequence has performed well since it started on 03-215 (8/03/03). It terminates on 03-218 (8/06/03). The mm303 sequence, successfully uplinked on 03-217 (8/0503), begins executing near the end of day on 03-218 (8/06/03).

Other – On 03-213 (8/01/03), MGS performed an Image Motion Compensation (IMC) experiment in the mz294 mini-sequence. A higher slew rate was commanded than ever previously used for MOC imaging. Results are pending.

Six Roll Only Targeted Observations (ROTOs) were performed successfully by the mz293 and mz295 mini-sequences. MGS has completed 744 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance.

Uplinks:

There were 24 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz294 IMC mini-sequence, the mz295 & mz296 ROTO mini-sequences, and the mm302 & mm303 background sequences. 7,886 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz296 and mz298 mini-sequences. mz297 will be used to briefly transmit telemetry not seen on a regular basis. Radio Science Occultation Egress Scans are scheduled for 03-229 (8/17/03) and 03-230 (8/19/03).


Wednesday, July 23, 2003 (DOY 197/19:00:00 to DOY 204/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2450 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1575 days
Total Mapping Orbits = 19,547
Total Orbits = 21,230

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm297 sequence executed successfully from 03-198 (7/17/03) through 03-200 (7/19/03). The mm298 sequence has performed well since it started on 03-201 (7/20/03). It terminates on 03-204 (7/23/03). The mm299 sequence, successfully uplinked on 03-203 (7/22/03), begins executing near the end of day on 03-204 (7/23/03).

Other – Twelve Roll Only Targeted Observations (ROTOs) were performed successfully by the mz289 and mz290 mini-sequences. MGS has completed 728 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance.

Uplinks:

There were 13 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz290 ROTO mini-sequence, and the mm298 & mm299 background sequences. 7,867 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz291 and mz292 mini-sequences. Radio Science Occultation Egress Scans are scheduled for 03-229 (8/17/03) and 03-230 (8/19/03).


Wednesday, July 16, 2003 (DOY 190/19:00:00 to DOY 197/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2443 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1568 days
Total Mapping Orbits = 19,462
Total Orbits = 21,145

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm295 sequence executed successfully from 03-191 (7/10/03) through 03-193 (7/12/03). The mm296 sequence has performed well since it started on 03-194 (7/13/03). It terminates on 03-197 (7/16/03). The mm297 sequence, successfully uplinked on 03-196 (7/15/03), begins executing near the end of day on 03-197 (7/16/03).

Other – Eleven Roll Only Targeted Observations (ROTOs) were performed successfully by the mz286 and mz288 mini-sequences. MGS has completed 716 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance. MGS experienced a second instance where a Payload Data Subsystem (PDS) internal software reset corrupted the engineering data telemetry stream. The SCT quickly diagnosed the problem and sent commands to perform an external PDS reset. This action returned the engineering telemetry back to normal within an hour.

Uplinks:

There were 18 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the PDS external reset commands, the mz287 Radio Science Occultation Egress Scan mini-sequence, the mz288 & mz289 ROTO mini-sequences, and the mm296 & mm297 background sequences. 7,854 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz289 and mz290 mini-sequences.


Wednesday, July 9, 2003 (DOY 183/19:00:00 to DOY 190/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2436 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1561 days
Total Mapping Orbits = 19,3760
Total Orbits = 21,059

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm293 sequence executed successfully from 03-184 (7/03/03) through 03-186 (7/05/03). The mm294 sequence has performed well since it started on 03-187 (7/06/03). It terminates on 03-190 (7/09/03). The mm295 sequence, successfully uplinked on 03-189 (7/08/03), begins executing near the end of day on 03-190 (7/09/03).

Other - The Mars Relay instrument UHF experiment with Stanford University was successfully completed on 03-184 (7/03/03).

No Roll Only Targeted Observations (ROTOs) were performed. MGS has completed 705 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance. A flight software patch was uplinked to improve the spacecraft's ability to recover from rare occasions when it misidentifies a star and corrupts its attitude knowledge. A portion of the attitude reinitialization code was previously disabled when it proved problematic for the current attitude configuration where the spacecraft is constantly pitched 16 degrees from nadir. This code is now invoked when the spacecraft misidentifies a star and corrupts its attitude knowledge to the point where fault protection returns the spacecraft to a nadir orientation. The combined actions of autonomously returning to nadir using the horizon sensors and invoking the attitude reinitialization code removes most of the attitude errors. It reduces the chance that MGS will enter Contingency Mode due to star processing problems.

Uplinks:

There were 15 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the flight software patch described above, the mz286 ROTO mini-sequence, and the mm294 & mm295 background sequences. 7,836 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs will resume on 03-191 (7/10/03) when the mz286 mini-sequence begins executing. Radio Science Occultation Egress Scans will commence on 03-192 (7/11/03) as part of the mz287 mini-sequence.


Wednesday, July 2, 2003 (DOY 176/19:00:00 to DOY 183/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2429 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1554 days
Total Mapping Orbits = 19,290
Total Orbits = 20,973

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm291 sequence executed successfully from 03-177 (6/26/03) through 03-179 (6/28/03). The mm292 sequence has performed well since it started on 03-180 (6/29/03). It terminates on 03-183 (7/02/03). The mm293 sequence, successfully uplinked on 03-182 (7/01/03), begins executing near the end of day on 03-183 (7/02/03).

Other – The Mars Relay instrument UHF experiment with Stanford University began on 03-182 (7/01/03) and will continue until 03-184 (7/03/03).

No Roll Only Targeted Observations (ROTOs) were performed. MGS has completed 705 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance.

Uplinks:

There were 14 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, and the mm292 & mm293 background sequences. 7,821 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs will resume after the spacecraft team modifies the MGS star catalog and uplinks a flight software patch to improve the spacecraft’s ability to recover from misidentifying a star. Radio Science Occultation Egress Scans are scheduled for 03-192 (7/11/03) and 03-193 (7/12/03).


Wednesday, June 25, 2003 (DOY 169/19:00:00 to DOY 176/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2422 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1547 days
Total Mapping Orbits = 19,205
Total Orbits = 20,888

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm289 sequence executed successfully from 03-170 (6/19/03) through 03-172 (6/21/03). The mm290 sequence has performed well since it started on 03-173 (6/22/03). It terminates on 03-176 (6/25/03). The mm291 sequence, successfully uplinked on 03-175 (6/24/03), begins executing near the end of day on 03-176 (6/25/03).

Other – No Roll Only Targeted Observations (ROTOs) were performed. MGS has completed 705 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance. The last few steps of C-mode recovery were accomplished to bring the TES and MAG/ER instruments to their nominal configuration. The TES instrument was powered-on and command files were loaded on 03-170 (6/19/03). A standard MAG/ER software patch was uplinked on 03-171 (6/20/03). All science instruments are performing nominally.

Uplinks:

There were 24 uplinks to the spacecraft during the past week. They included contingency mode recovery commands, new star catalog and ephemeris files, nominal instrument command loads, and the mm289, mm290, & mm291 background sequences. 7,807 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs will resume after the project reviews the data associated with the latest contingency mode entry and determines what follow-up actions should be taken. Mars Relay instrument UHF experiments are scheduled with Stanford University between 03-182 (7/01/03) and 03-184 (7/03/03). Radio Science Occultation Egress Scans are scheduled for 03-192 (7/11/03) and 03-193 (7/12/03).


Wednesday, June 18, 2003 (DOY 162/19:00:00 to DOY 169/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2415 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1540 days
Total Mapping Orbits = 19,119
Total Orbits = 20,802

Recent Events:

Background Sequences – MGS has recovered from contingency mode. It is operating under the control of the mm288d background sequence. Spacecraft subsystem configurations are all nominal. The MOC, MOLA, and MAG/ER,science instruments are operating nominally. The TES instrument will be powered via real-time commands within the first few hours of the mm289c background sequence. MM289c goes active on 03-169 (6/18/03) at 23:57:00 SCET UTC.

Other – No Roll Only Targeted Observations (ROTOs) were performed. MGS has completed 705 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance.

Uplinks:

There were 87 uplinks to the spacecraft during the past week. They included contingency mode recovery commands, new star catalog and ephemeris files, nominal instrument command loads, and the mm288 background sequence. 7,683 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs will resume after the project reviews the data associated with the latest contingency mode entry and determines what follow-up actions should be taken. Mars Relay instrument UHF experiments are scheduled with Stanford University between 03-182 (7/01/03) and 03-184 (7/03/03). Radio Science Occultation Egress Scans are scheduled for 03-192 (7/11/03) and 03-193 (7/12/03).


Wednesday, June 11, 2003 (DOY 155/19:00:00 to DOY 162/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2408 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1533 days
Total Mapping Orbits = 19,033
Total Orbits = 20,716

Recent Events:

Background Sequences – The mm285 sequence executed successfully from 03-156 (6/05/03) through 03-158 (6/07/03). The mm286 sequence terminated prematurely on 03-162 (6/11/03) at 10:00:57 when MGS entered contingency mode. Preliminary analysis indicates that Star Identification Software had difficulty processing stars in a particular region of the celestial sphere. There seems to be an incompatibility between the stars that MGS expects to detect and the stars that its Celestial Sensor Assembly actually detects. Contingency mode recovery is underway. The mm287 sequence, successfully uplinked on 03-161 (6/10/03), was terminated before its programmed start time to allow time for the recovery.

Other – Sixteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz281 & mz282 mini-sequences. MGS has completed 705 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report nominal health and performance for the contingency mode configuration.

Uplinks:

There were 19 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz282 ROTO mini-sequence, the mm286 & mm287 background sequences, and contingency mode recovery commands. 7,696 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs will resume following contingency mode recovery. Mars Relay instrument UHF experiments are scheduled with Stanford University between 03-182 (7/01/03) and 03-184 (7/03/03). Radio Science Occultation Egress Scans are scheduled for 03-192 (7/11/03) and 03-193 (7/12/03).


Wednesday, June 04, 2003 (DOY 148/19:00:00 to DOY 155/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2401 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1526 days
Total Mapping Orbits = 18,947
Total Orbits = 20,630

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm283 sequence executed successfully from 03-149 (5/29/03) through 03-151 (5/31/03). The mm284 sequence has performed well since it started on 03-152 (6/01/03). It terminates on 03-155 (6/04/03). The mm285 sequence, successfully uplinked on 03-154 (6/03/03), begins executing near the end of day on 03-155 (6/04/03).

Other – Phobos images were taken by the MOC on 03-152 (6/01/03) in the mz279 mini-sequence. Image results are pending.

Eleven Roll Only Targeted Observations (ROTOs) were performed successfully by the mz278 & mz280 mini-sequences. MGS has completed 689 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and performance.

Uplinks:

There were 20 uplinks to the spacecraft during the past week. They included new star catalog and ephemeris files, nominal instrument command loads, the mz278, mz280 & mz281 ROTO mini-sequences, the mz279 Phobos Imaging mini-sequence, and the mm284 & mm285 background sequences. 7,677 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz281 and mz282 mini-sequences. Mars Relay instrument UHF experiments are scheduled with Stanford University between 03-182 (7/01/03) and 03-184 (7/03/03). Radio Science Occultation Egress Scans are scheduled for 03-192 (7/11/03) and 03-193 (7/12/03).




Wednesday, March 05, 2003 (DOY 057/19:00:00 to DOY 064/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2310 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1435 days
Total Mapping Orbits = 17,834
Total Orbits = 19,517

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data.  The mm257 sequence executed successfully from 03-058 (2/27/03) through 03-060 (3/01/03).  The mm258 sequence has performed well since it started on 03-061 (3/02/03).  It terminates on 03-064 (3/05/03).  The mm259 sequence, successfully uplinked on 03-063 (3/04/03), begins executing near the end of day on 03-064 (3/05/03).

Other  - Ten Roll Only Targeted Observations (ROTOs) were performed successfully by the mz249 and mz250 mini-sequences.  MGS has completed 581 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and performance.  Electrical power margin is being managed by utilizing on-board solar array pointing scripts instead of auto-tracking.  On 03-064 (3/05/03), the “three-part motion 25-degree offpoint” scripts replaced the “three-part motion 0-degree offpoint” scripts.  This decreases the excess energy being produced by the solar panels thereby preserving life in the Partial Shunt Assemblies.

Uplinks:

There were 19 uplinks to the spacecraft during the past week.  They included new star catalog and ephemeris files, nominal instrument command loads, three 25-degree offpoint solar array motion scripts, the mz250 & mz251 ROTO mini-sequences, and the mm258 & mm259 background sequences.  7,456 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for the mz251 & mz252 mini-sequences.  A Delta-DOR experiment is scheduled for 03-074 (3/15/03).  Another Solar Array and HGA Flex Modes Test is scheduled for 03-076 (3/17/03).
 


Wednesday, November 27, 2002 (DOY 324/19:00:00 to DOY 331/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2212 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1337 days
Total Mapping Orbits = 16,635
Total Orbits = 18,318

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm229 sequence executed successfully from 02-325 (11/21/02) through 02-327 (11/23/02). The mm230 sequence has performed well since it started on 02-328 (11/24/02). It terminates on 02-331 (11/27/02). The mm231 sequence, successfully uplinked on 02-330 (11/26/02), begins executing near the end of day on 02-331 (11/27/02).

Other - Fifteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz219, mz220, and mz221 mini-sequences. MGS has completed 418 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and performance.

Uplinks:

There have been 18 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, the mz221, & mz222 ROTO mini-sequences, and the mm230 & mm231 background sequences. 7,214 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz221, mz222, & mz223 mini-sequences. A DDOR experiment will be conducted on 02-332 (11/28/02). A Nav acceptance test is scheduled for 02-333 (11/29/02). The next series of Radio Science Occultation Egress measurements will occur from 02-336 (12/02/02) to 02-337 (12/03/02) as part of mz223.


Wednesday, November 13, 2002 (DOY 310/19:00:00 to DOY 317/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2198 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1323 days
Total Mapping Orbits = 16,465
Total Orbits = 18,148

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm225 sequence executed successfully from 02-311 (11/07/02) through 02-313 (11/09/02). The mm226 sequence has performed well since it started on 02-314 (11/10/02). It terminates on 02-317 (11/13/02). The mm227 sequence, successfully uplinked on 02-316 (11/12/02), begins executing near the end of day on 02-317 (11/13/02).

Twelve Roll Only Targeted Observations (ROTOs) were performed successfully by the mz216, and mz217 mini-sequences. MGS has completed 391 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and performance.

Uplinks:

There have been 15 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, the mz217, & mz218 ROTO mini-sequences, and the mm227 & mm225 background sequences. 7,179 command files have been radiated to the spacecraft since launch.

Other:

The MGS DSN schedule was altered this last week to accommodate Odyssey's safe mode recovery efforts. A few uplink periods were given up to Odyssey, though this did not prevent any MGS commands from being uplinked. No MGS downlink time was lost due to the schedule change.

Upcoming Events:

ROTOs are planned for next week in the mz218 & mz219 mini-sequences. A DDOR experiment will be conducted on 02-332 (11/28/02). A Nav acceptance test is scheduled for 02-333 (11/29/02). The next Radio Science Egress mini-sequence is schedule to be from 02-336 (12/02/02) to 02-337 (12/03/02).


Wednesday, October 30, 2002 (DOY 296/19:00:00 to DOY 303/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2184 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1309 days
Total Mapping Orbits = 16,292
Total Orbits = 17,975

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm221 sequence executed successfully from 02-297 (10/24/02) through 02-299 (10/26/02). The mm222 sequence has performed well since it started on 02-300 (10/27/02). It terminates on 02-303 (10/30/02). The mm223 sequence, successfully uplinked on 02-302 (10/29/02), begins executing near the end of day on 02-303 (10/30/02).

Other - Eleven Radio Science Occultation Egress Scans were performed on 02-302 (10/29/02) and 02-303 (10/30/02). Results are pending.

Twelve Roll Only Targeted Observations (ROTOs) were performed successfully by the mz211, mz212 & mz213 mini-sequences. MGS has completed 366 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and performance.

Uplinks:

There have been 16 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, the mz213 ROTO mini-sequence, and the mm222 & mm223 background sequences. 7,143 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz213, mz214, & mz215 mini-sequences. A DDOR experiment will be conducted on 02-305 (11/01/02).


Wednesday, October 16, 2002 (DOY 289/19:00:00 to DOY 296/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2177 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1302 days
Total Mapping Orbits = 16,206
Total Orbits = 17,889

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm219 sequence executed successfully from 02-290 (10/17/02) through 02-292 (10/19/02). The mm220 sequence has performed well since it started on 02-293 (10/20/02). It terminates on 02-296 (10/23/02). The mm221 sequence, successfully uplinked on 02-295 (10/22/02), begins executing near the end of day on 02-296 10/23/02).

Other - Eight Roll Only Targeted Observations (ROTOs) were performed successfully by the mz210 & mz211 minisequences. MGS has completed 354 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been 17 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, the mz211 & mz212 ROTO mini-sequences, and the mm220 & mm221 background sequences. 7,127 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz211, mz212, & mz213 mini-sequences. Radio Science Occultation Egress Scans are scheduled for 02-302 (10/29/02) and 02-303 (10/30/02). The DDOR experiment slipped one day to optimize DSN coverage. It is now scheduled for 02-305 (11/01/02).


Wednesday, October 09, 2002 (DOY 275/19:00:00 to DOY 282/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2163 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1288 days
Total Mapping Orbits = 16,036
Total Orbits = 17,719

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm215 sequence executed successfully from 02-276 (10/03/02) through 02-278 (10/05/02). The mm216 sequence has performed well since it started on 02-279 (10/06/02). It terminates on 02-282 (10/09/02). The mm217 sequence, successfully uplinked on 02-281 (10/08/02), begins executing near the end of day on 02-282 10/09/02).

Other - Fifteen Roll Only Targeted Observations (ROTOs) were performed successfully by the mz206 & mz207 minisequences. MGS has completed 337 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been 13 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, the mz207 & mz208 ROTO mini-sequences, and the mm216 & mm217 background sequences. 7,090 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz208 & mz209 mini-sequences.


Wednesday, October 02, 2002 (DOY 268/19:00:00 to DOY 275/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2156 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1281 days
Total Mapping Orbits = 15,950
Total Orbits = 17,633

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm213 sequence executed successfully from 02-269 (9/26/02) through 02-271 (9/28/02). The mm214 sequence has performed well since it started on 02-272 (9/29/02). It terminates on 02-275 (10/02/02). The mm215 sequence, successfully uplinked on 02-274 (10/01/02), begins executing near the end of day on 02-275 10/02/02).

Other - Nine Roll Only Targeted Observations (ROTOs) were performed successfully by the mz203, mz204, & mz205 minisequences. MGS has completed 322 ROTOs to date.

The Radio Science egress scans contained in the mz205 mini-sequence performed nominally. Radio Science Operations reported that the SNR at SPC-60 was lower than expected due to heavy rain, but all ten egress measurements were successfully acquired.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been 21 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, the mz205 ROTO & Radio Science Egress Scan mini-sequence, the mz206 ROTO mini-sequence, and the mm214 & mm215 background sequences. 7,077 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz206 & mz207 mini-sequences.


Wednesday, September 25, 2002 (DOY 261/19:00:00 to DOY 268/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2149 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1274 days
Total Mapping Orbits = 15,864
Total Orbits = 17,547

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm211 sequence executed successfully from 02-262 (9/19/02) through 02-264 (9/21/02). The mm212 sequence has performed well since it started on 02-265 (9/22/02). It terminates on 02-268 (9/25/02). The mm213 sequence, successfully uplinked on 02-267 (9/24/02), begins executing near the end of day on 02-268 (9/25/02).

Other - Seven Roll Only Targeted Observations (ROTOs) were performed successfully by the mz201, mz202, & mz203 minisequences. MGS has completed 213 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been 16 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, the mz203 & mz204 ROTO mini-sequences, and the mm212 & mm213 background sequences. 7,056 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz204 & mz205 mini-sequences. Radio Science Occultation Egress Scans, also contained in mz205, will be performed on 02-273 (9/30/02) and 02-274 (10/01/02). The DDOR experiment scheduled for 02-276 (10/03/03) has been cancelled due to scheduling constraints.


Wednesday, September 18, 2002 (DOY 254/19:00:00 to DOY 261/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2142 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1267 days
Total Mapping Orbits = 15,779
Total Orbits = 17,462

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm209 sequence executed successfully from 02-255 (9/12/02) through 02-257 (9/14/02). The mm210 sequence has performed well since it started on 02-258 (9/15/02). It terminates on 02-261 (9/18/02). The mm211 sequence, successfully uplinked on 02-260 (9/17/02), begins executing near the end of day on 02-261 (9/18/02).

Other - The three Roll Only Targeted Observations (ROTOs) reported as successful last week were in fact not successful. The images taken during those ROTOs and the first two ROTOs in mz200 were distorted because the spacecraft was slewing slowly while the images were being taken. The relative slew rate parameter had been set to orbital rate while the equator-crossing software patch was being loaded on 02-248 (9/05/02). The parameter was not reset to zero following the patch update. The problem was discovered on 02-255 (9/12/02) and corrected on 02-256 (9/13/02). The following four ROTOs in mz200 and six ROTOs in mz201 were performed successfully. MGS has successfully completed 306 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been 23 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files; instrument command loads; the mi0654 slew-rate parameter update; the mz200, mz201 & mz202 ROTO mini-sequences; and the mm210 & mm211 background sequences. 7,040 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz201, mz202, & mz203 mini-sequences. Radio Science Occultation Egress Scans will be performed on 02-273 (9/30/02) and 02-274 (10/01/02). A DDOR experiment is scheduled for 02-276 (10/03/03).


Wednesday, September 11, 2002 (DOY 247/19:00:00 to DOY 254/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2135 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1260 days
Total Mapping Orbits = 15,693
Total Orbits = 17,376

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm207 sequence executed successfully from 02-248 (9/05/02) through 02-250 (9/07/02). The mm208 sequence has performed well since it started on 02-251 (9/08/02). It terminates on 02-254 (9/11/02). The mm209 sequence, successfully uplinked on 02-253 (9/10/02), begins executing near the end of day on 02-254 (9/11/02).

Other - Three Roll Only Targeted Observations (ROTOs) were performed successfully by the mz199 minisequence. The two ROTOs contained in mz198 were not executed because mz198 could not be uplinked. Difficulties at the DSN station prevented successful uplink of the requisite payload command files. MGS has completed 299 ROTOs to date.

Flight software was successfully updated to ensure that MGS telemeters correct equator-crossing times when it is in the CSA Backup AACS mode and nadir pointed. MGS recently began managing system momentum by periodically maneuvering between the relay-16 attitude and the nadir attitude. While effectively reducing propellant consumption, this new method of managing system momentum opened a small window of vulnerability where equator-crossing times would be computed incorrectly. The flight software patch effectively eliminates this vulnerability.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

Twenty-two of thirty command files were successfully uplinked to MGS during the past week. DSN station related timing anomalies in the uplink path resulted in MGS properly rejecting seven command files. The successful uplinks included new star catalog and ephemeris files, instrument command loads, the mi0644 equator crossing flight software patch, the mz199 ROTO mini-sequence, and the mm208 and mm209 background sequences. 7,017 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz200 and mz201 mini-sequences. Radio Science Occultation Egress Scans will be performed on 02-273 (9/30/02) and 02-274 (10/01/02). A DDOR experiment is scheduled for 02-276 (10/03/03).


Wednesday, September 04, 2002 (DOY 240/19:00:00 to DOY 247/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2128 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1253 days
Total Mapping Orbits = 15,607
Total Orbits = 17,290

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm205 sequence executed successfully from 02-241 (8/29/02) through 02-243 (8/31/02). The mm206 sequence has performed well since it started on 02-244 (9/01/02). It terminates on 02-247 (9/04/02). The mm207 sequence, successfully uplinked on 02-246 (9/03/02), begins executing near the end of day on 02-247 (9/04/02).

Other - Five Roll Only Targeted Observations (ROTOs) were performed successfully by the mz196 & mz197 minisequences. MGS has completed 296 ROTOs to date.

A DSN Network Simplification Project (NSP) tracking test was performed on 02-242 (8/30/02).

A Delta Differential One-Way Range (DDOR) experiment was performed on 02-246 (9/03/01). Data from DDOR experiments are helpful in calibrating the interplanetary navigation system.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been 8 uplinks to the spacecraft during the past week, including instrument command loads, the mz197 ROTO mini-sequence, and the mm206 and mm207 background sequences. 6,987 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz198 and mz199 mini-sequences.


Wednesday, August 21, 2002 (DOY 226/19:00:00 to DOY 233/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2114 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1239 days
Total Mapping Orbits = 15,436
Total Orbits = 17,119

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm201 sequence executed successfully from 02-226 (8/14/02) through 02-231 (8/19/02). The mm202 sequence has performed well since it started on 02-232 (8/20/02). It terminates on 02-234 (8/22/02). The mm203 sequence, successfully uplinked on 02-232 (8/20/02), begins executing near the end of day on 02-233 (8/21/02).

Other - The Command Loss Timer (CLT) was reset to 104 hours on 02-228 (8/16/02).

The mz193 Flexible Modes Test was performed early on 02-231 (8/19/02) to characterize the dynamics of the solar arrays and HGA gimbal. All recorded test has been played back and is in the process of being analyzed by AACS engineers.

The MOC was successfully turned-on and its replacement heater turned-off on 02-231 (8/19/02). The MOC was turned off for solar conjunction so no Roll Only Targeted Observations (ROTOs) were performed. MGS has completed 285 ROTOs to date. ROTOs resume on 02-234 (8/22/02).

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been 29 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, CLT reset commands, MOC commands, instrument command loads, the mz193 flex modes mini-sequence, the mz194 ROTO mini-sequence, and the mm202 and mm203 background sequences. 6,959 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz194 and mz195 mini-sequences.


Wednesday, August 14, 2002 (DOY 219/19:00:00 to DOY 226/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2107 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1232 days
Total Mapping Orbits = 15,351
Total Orbits = 17,034

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm200 sequence has performed well since it started on 02-216 (8/02/02). It terminates on 02-226 (8/14/02). The mm201 sequence, successfully uplinked on 02-214 (8/02/02), begins executing near the end of day on 02-226 (8/14/02). It covers through the end of solar conjunction.

Other - The MOC has been turned off for solar conjunction so no Roll Only Targeted Observations (ROTOs) were performed. MGS has completed 285 ROTOs to date.

Spacecraft Health:

Spacecraft subsystems report good health and status.

Uplinks:

There have been no uplinks to the spacecraft during the past week due to the solar conjunction command moratorium. 6,930 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The CLT will be reset to 104 hours on 02-228 (8/16/02). The mm202 background sequence will be uplinked on 02-229 (8/17/02). The mz193 Flexible Modes Test mini-sequence will be uplinked that same day. The test itself will be performed early on 02-231 (8/19/02) to characterize the dynamics of the solar arrays and HGA gimbal. The MOC will be turned on later that day, 02-231 (8/19/02). The mz203 background sequence will be uplinked on 02-232 (8/20/02).

 


Wednesday, July 31, 2002 (DOY 205/19:00:00 to DOY 212/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2093 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1218 days
Total Mapping Orbits = 15,179
Total Orbits = 16,862

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm198 sequence executed successfully from 02-206 (7/25/02) through 02-208 (7/27/02). The mm199 sequence has performed well since it started on 02-209 (7/28/02). It terminates on 02-213 (8/01/02). The mm200 sequence, successfully uplinked on 02-212 (7/31/02), begins executing near the end of day on 02-213 (8/01/02).

Other - Three Roll Only Targeted Observations (ROTOs) were performed successfully by the mz192 mini-sequence. MGS has completed 285 ROTOs to date.

The MOC instrument was turned off on 02-212 (7/31/02) in preparation for solar conjunction. Its replacement heaters will keep it thermally safe until it is turned back on following conjunction.

Spacecraft Health:

Spacecraft subsystems report good health and status. The signatures of the Payload Data Subsystem (PDS) software resets from several weeks ago are similar to two PDS software resets that occurred in 1999. PDS software developer's assessed the root cause for the 1999 resets to be the reprogramming of science data bandwidth. Bandwidth originally designed for the Mars Orbiter GRS and PMIRR instruments was reallocated to increase MGS MOC and TES bandwidth since GRS and PMIRR were not being flown on MGS. This reprogramming altered the PDS' finely tuned timing and marginal dynamic memory reserve such that (occasional) process memory starvation became possible. PDS' inability to complete a process due to insufficient memory is one of several triggers for a software reset.

Uplinks:

There have been 10 uplinks to the spacecraft during the past week, including instrument command loads, the mz192 ROTO mini-sequence, and the mm199 and mm200 background sequences. 6,908 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MM201, the second of two solar conjunction background sequences will be uplinked on 02-214 (8/02/02). It covers the later part of solar conjuction through 02-231 (8/19/02). Downlink during solar conjunction shall be real time, low rate data only with no playbacks. Recording will be done throughout the sequences on SSR 2A only, should a playback of recent data be necessary. The Command Loss Timer (CLT) will be set to 18 days. There will be no ranging during these sequences. The telecom subsystem will be configured back to normal Beta Supplement operations at the end of sequence mm201.

Another Flex Modes Test of the solar arrays and HGA gimbal will be performed because of data losses during the playback. We are looking at opportunities during the transition between the end of solar conjunction and the start of nominal beta-supplement sequences.

ROTOs are suspended until after solar conjunction.


Wednesday, July 24, 2002 (DOY 198/19:00:00 to DOY 205/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2086 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1211 days
Total Mapping Orbits = 15,094
Total Orbits = 16,777

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm196 sequence executed successfully from 02-199 (7/18/02) through 02-201 (7/20/02). The mm197 sequence has performed well since it started on 02-202 (7/21/02). It terminates on 02-205 (7/24/02). The mm198 sequence, successfully uplinked on 02-204 (723/02), begins executing near the end of day on 02-205 (7/24/02).

Other - Seven Roll Only Targeted Observations (ROTOs) were performed successfully by the mz190 & mz191 mini-sequences. MGS has completed 282 ROTOs to date.

MGS performed another Flex Mode Test of the SA panels on DOY 199. The results are pending.

Spacecraft Health:

Spacecraft subsystems report good health and status. The science teams are investigating the cause of the PDS soft resets from last week.

Uplinks:

There have been 17 uplinks to the spacecraft during the past week, including star catalogs and ephemeris files covering 20 days, instrument command loads, the mz190 and mz191 ROTO mini-sequences, and the mm197 and mm198 background sequences. 6,898 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MGS S/C team is preparing for solar conjunction. The next 2 background sequences [mm200 (13 days, 214 -226) and mm201 (5 days, 227-231)] shall cover the solar conjunction period. Downlink during solar conjunction shall be real time, low rate data only with no playbacks. Recording will be done throughout the sequences on SSR 2A only, should a playback of recent data be necessary. The CLT will be set to 18 days. MOC will be turned off and it's heaters turned on prior to mm200. There will be no ranging during these sequences. The telecom subsystem will be configured back to normal Beta Supplement operations at the end of sequence mm201.

ROTOs are suspended until after solar conjunction.


Wednesday, June 26, 2002 (DOY 170/19:00:00 to DOY 177/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2058 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1183 days
Total Mapping Orbits = 14,751
Total Orbits = 16,434

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm188 sequence executed successfully from 02-171 (6/20/02) through 02-173 (6/22/02). The mm189 sequence has performed well since it started on 02-174 (6/23/02). It terminates on 02-177 (6/26/02). The mm190 sequence, successfully uplinked on 02-176 (6/25/02), begins executing on 02-177 (6/26/02).

Other - On 02-172 (6/21/02) and 02-177 (6/26/02), DSS-15 performed acquisition and tracking tests with MGS to characterize the current performance capabilities of both MGS receivers. Updating our knowledge of the acquisition and tracking performance of the receivers will allow us to update the uplink sweep parameters for MGS.

Seven Roll Only Targeted Observations (ROTOs) were performed successfully by the mz181 & mz182 minisequences. MGS has completed 260 ROTOs to date.

Spacecraft Health: All spacecraft subsystems report good health and status. Similar to last week, the star identification software had some difficulty identifying stars following two of the ROTOs. The flight software modifications we made several weeks ago continue to work as designed and STAREX converged after autonomously resetting. We have instituted a process that should improve STAREX performance by modifying the star catalog when we determine that problematic stars are about to enter the CSA field of view.

Uplinks:

There have been 23 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mz182 and mz183 ROTO mini-sequences, and the mm189 and mm190 background sequences. 6,828 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz183 and mz184 mini-sequences.


Wednesday, June 19, 2002 (DOY 163/19:00:00 to DOY 170/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2051 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1175 days
Total Mapping Orbits = 14,665
Total Orbits = 16,348

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm186 sequence executed successfully from 02-164 (6/13/02) through 02-166 (6/15/02). The mm187 sequence has performed well since it started on 02-167 (6/16/02). It terminates on 02-170 (6/19/02). The mm188 sequence, successfully uplinked on 02-169 (6/18/02), begins executing on 02-170 (6/19/02).

Other - Five Roll Only Targeted Observations (ROTOs) were performed successfully by the mz179 & mz180 minisequences. MGS has completed 253 ROTOs to date.

Spacecraft Health: All spacecraft subsystems report good health and status. The star identification software had some difficulty identifying stars following four of the ROTOs, but converged nicely in each case after performing an autonomous reset. This proves that the software modifications we made several weeks ago are working as designed. The characteristics of some of the stars may have changed since the original source star catalog was developed in 1950, so we are in the process of updating the star catalog to reflect those changes.

Uplinks:

There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mz180 and mz181 ROTO mini-sequences, and the mm187 and mm188 background sequences. 6,805 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz181 and mz182 mini-sequences.

On 02-172 (6/21/02) and 02-177 (6/26/02), DSS-15 will perform acquisition and tracking tests with MGS to characterize the current performance capabilities of both MGS receivers. It is suspected that the acquisition and tracking performance of one or both spacecraft receivers has degraded since launch. No measurement of this performance has been conducted since 1996. Knowledge of the acquisition and tracking performance of each transponder helps ensure that the proper uplink sweep parameters will be used for every uplink.


Wednesday, June 5, 2002 (DOY 149/19:00:00 to DOY 156/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2037 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1161 days
Total Mapping Orbits = 14,494
Total Orbits = 16,177

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm182 sequence executed successfully from 02-150 (5/30/02) through 02-152 (6/01/02). The mm183 sequence has performed well since it started on 02-153 (6/02/02). It terminates on 02-156 (6/05/02). The mm184 sequence, successfully uplinked on 02-155 (6/04/02), begins executing on 02-156 (6/05/02).

Other - Three Roll Only Targeted Observations (ROTOs) were performed successfully by the mz175 & mz176 minisequences. MGS has completed 240 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status. Attitude and Articulation Control Subsystem engineers (AACS) are monitoring an interesting shift in the z-axis gyro bias trend. They are investigating whether the shift correlates to any known physical phenomenon. They are also developing alternate methods of controlling the spacecraft should there be further degradation within the subsystem. Presently, the z-axis gyro bias appears to be stabilizing at a new value within specifications. Other telemetry indications appear nominal.

Uplinks:

There have been 20 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mz174 and mz175 ROTO mini-sequences, and the mm183a and mm184a background sequences. 6,770 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MOLA Make-Up Heater will be turned off on 02-156 (6/05/02) to maintain adequate power margin as MGS approaches aphelion. ROTOs are planned for next week in the mz177 and mz178 mini-sequences.


Wednesday, May 29, 2002 (DOY 142/19:00:00 to DOY 149/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2030 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1154 days
Total Mapping Orbits = 14,407
Total Orbits = 16,090

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm180 sequence executed successfully from 02-143 (5/23/02) through 02-145 (5/25/02). The mm181 sequence has performed well since it started on 02-146 (5/26/02). It terminates on 02-149 (5/29/02). The mm182 sequence, successfully uplinked on 02-148 (5/28/02), begins executing on 02-149 (5/29/02).

Other - Two Roll Only Targeted Observations (ROTOs) were performed successfully on 02-143 (5/23/02) by the mz174 minisequence. MGS has completed 237 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 13 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the mm181a and mm182a background sequences. 6,750 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs are planned for next week in the mz175 and mz176 mini-sequences.


Wednesday, May 22, 2002 (DOY 135/19:00:00 to DOY 142/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2023 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1147 days
Total Mapping Orbits = 14,322
Total Orbits = 16,005

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm178 sequence executed successfully from 02-136 (5/16/02) through 02-138 (5/18/02). The mm179 sequence has performed well since it started on 02-139 (5/19/02). It terminates on 02-142 (5/22/02). The mm180 sequence, successfully uplinked on 02-141 (5/21/02), begins executing on 02-142 (5/22/02).

Other - MGS completed the last two of five MOC focus calibrations this week. No ROTOs were performed this week. They will resume on 02-143 (5/23/02). MGS has completed 235 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 19 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mz172b & mz173c MOC Focus Calibration mini-sequences, the mm179a and mm180a background sequences, and the mz174a ROTO mini-sequence. 6,737 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs will resume on 02-143 (5/23/02). They should continue on a regular basis thereafter depending upon the availability of non-communications orbits in each background sequence. During the beta-supplement phase of the mission, in order to prevent the HGA from impacting the HGA boom, we restrict ROTOs to non-communications orbits when the HGA remains fixed with respect to the spacecraft body.


Wednesday, May 8, 2002 (DOY 121/19:00:00 to DOY 128/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2009 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1133 days
Total Mapping Orbits = 14,152
Total Orbits = 15,835

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm174 sequence executed successfully from 02-122 (5/2/02) through 02-124 (5/04/02). The mm175 sequence has performed well since it started on 02-125 (5/05/02). It terminates on 02-128 (5/08/02). The mm176 sequence, successfully uplinked on 02-127 (5/07/02), begins executing on 02-128 (5/08/02).

Other - No ROTOs were performed this week. The team has uplinked two software modifications (patches) to improve star processing and reduce the risk of entering C-mode. The first patch, uplinked during the April C-mode recovery, prevents attitude knowledge from being corrupted if star processing is reset while MGS is pointed off-nadir. The second patch, uplinked this week, corrects the way STIME is calculated. STIME is the time that has passed since the last identified star. STAREX used to simply count the number of seconds since the last identified star. Because STAREX processing is briefly inhibited whenever the HGA or solar arrays stop and start moving, the counter also stopped. This introduced small timing errors into star processing that resulted in STAREX discarding stars that it normally would have identified. STAREX now calculates STIME by subtracting the time of the last identified star from the present time, so brief interruptions to star processing do not adversely affect STIME. With these flight software improvements in place, the spacecraft team recommends relaxing some of the ROTO restrictions currently in place. MGS has completed 235 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 21 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the STIME patch, the mm175 and mm176 background sequences, and no-op commands to test the new command system scheduled to be online this summer. 6,698 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The first three of five MOC focus calibrations are scheduled for 02-132 (5/12/02), 02-133 (5/13/02), and 02-134 (5/14/02). The last two are scheduled for the following week. ROTOs will resume following the MOC focus calibrations.



Wednesday, May 1, 2002 (DOY 114/19:00:00 to DOY 121/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 2002 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1126 days
Total Mapping Orbits = 14,066
Total Orbits = 15,749

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm172 sequence executed successfully from 02-115 (4/25/02) through 02-117 (4/27/02). The mm173 sequence has performed well since it started on 02-118 (4/28/02). It terminates on 02-121 (5/01/02). The mm174 sequence, successfully uplinked on 02-120 (4/30/02), begins executing on 02-121 (5/01/02).

Other - No ROTOs were performed this week. The team is identifying, building and testing flight software modifications to improve star processing and reduce the risk of entering C-mode. The goal is to safely eliminate the need for some of the ROTO restrictions so that ROTOs can be performed more frequently. MGS has completed 235 ROTOs to date.

Two new 4-part motion solar array positioning command scripts were uplinked this week. MGS will transition from the 3-part motion scripts to the 4-part motion scripts when the mm174 background sequence begins executing. The new scripts will compensate for the decreasing power levels MGS experiences as it approaches aphelion.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 28 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the mm173 and mm174 background sequences. 6,677 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MOC focus calibrations are scheduled for mid-May.


Wednesday, April 24, 2002 (DOY 107/19:00:00 to DOY 114/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1995 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1119 days
Total Mapping Orbits = 13,979
Total Orbits = 15,662

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm170 sequence executed successfully from 02-108 (4/18/02) through 02-110 (4/20/02). The mm171 sequence has performed well since it started on 02-111 (4/21/02). It terminates on 02-114 (4/24/02). The mm172 sequence, successfully uplinked on 02-113 (4/23/02), begins executing on 02-114 (4/24/02).

Other - No ROTOs were performed this week. There were no MER landing site targets within the available windows of opportunity. The team is identifying, building and testing flight software modifications to improve star processing and reduce the risk of entering C-mode. The goal is to safely eliminate the need for some of the ROTO restrictions so that ROTOs can be performed more frequently. MGS has completed 235 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 8 uplinks to the spacecraft during the past week, including instrument command loads, and the mm171 and mm172 background sequences. 6,649 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MOC focus calibrations are scheduled for mid-May.


Wednesday, April 17, 2002 (DOY 100/19:00:00 to DOY 107/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1988 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1112 days
Total Mapping Orbits = 13,894
Total Orbits = 15,577

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm168 sequence executed successfully from 02-101 (4/11/02) through 02-103 (4/13/02). The mm169 sequence has performed well since it started on 02-104 (4/14/02). It terminates on 02-107 (4/17/02). The mm170 sequence, successfully uplinked on 02-106 (4/16/02), begins executing on 02-107 (4/17/02).

Other - All science instruments are powered and operating nominally. No ROTOs were accomplished this week. MGS has completed 235 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 20 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the mm169 and mm170 background sequences. 6,641 command files have been radiated to the spacecraft since launch.

Upcoming Events:

ROTOs will resume next week with the mz171 mini-sequence.


Wednesday, April 10, 2002 (DOY 093/19:00:00 to DOY 100/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1981 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1105 days
Total Mapping Orbits = 13,809
Total Orbits = 15,492

Recent Events:

Background Sequences - We have recovered MGS from C-Mode. It is nadir pointed with downlink communications through the HGA. An on-board script that is triggered every time the spacecraft emerges from solar eclipse is controlling HGA movement and TWTA cycling. The mm168 background sequence begins tonight at 23:57:00 SCET UTC on 02-101 (4/10/02). It will return the spacecraft to the relay-16 attitude and commence normal operations.

Other - All on-board recorded data have been played back. A STAREX flight software patch has been uplinked to prevent attitude knowledge from being corrupted if star processing is reset while MGS is pointed off-nadir. The MOC has been powering up and is imaging MARS.

No ROTOs were accomplished this week. MGS has completed 235 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 60 uplinks to the spacecraft during the past week, including C-mode recovery commands, new star catalogs and ephemeris files, instrument command loads, STAREX flight software patch, the mz168 return to nadir mini-sequence, the mz169 data playback mini-sequence, the mm168 background sequence, and the mz170 science instrument turn-on minisequence. 6,561 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MOLA, MAG/ER, and TES science instruments will be powered on 02-101 (4/10/02).


Wednesday, April 03, 2002 (DOY 086/19:00:00 to DOY 093/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1974 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1098 days
Total Mapping Orbits = 13,723
Total Orbits = 15,406

Recent Events:

Background Sequences - The mm164 sequence executed successfully from 02-087 (3/28/02) through 02-089 (3/30/02). The mm165 sequence performed well from 02-090 (3/31/02) until it was terminated prematurely by Contingency mode (C-mode). The spacecraft entered C-mode at 22:22:21 SCET UTC on 02-091 (4/01/02) due to a star processing problem. Presently the spacecraft team is progressing through the C-mode recovery procedure. The spacecraft is performing nominally in the C-mode configuration. The DSN stations are able to lock onto the 10 bps downlink signal and command at the 7.8125 bit rate.

MGS should be able to achieve inertial reference later this evening, allowing us to return to a nadir attitude within the next couple of days. Playing back data, powering up science instruments, and returning to background stored sequence control will follow. The recovery process will also include modifying flight software to prevent corrupting attitude knowledge when star processing is reset while MGS is pointed off-nadir. The spacecraft team has discovered that a small subroutine within the flight software is incompatible with sustained off-nadir operations. MGS software was designed for a nadir pointed mapping mission. Off-nadir mapping operations started in August 2001 to extend mission life by conserving propellant.

Other - MGS successfully executed one ROTO imaging scan on 02-088 (03/29/02) in the MZ167 mini-sequence. MGS has completed 235 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 37 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mm165 background sequence, and C-mode recovery commands. 6,561 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The project will complete the C-mode recovery, fix the flight software, power the science instruments, and return MGS to background stored sequence control.


Wednesday, March 27, 2002 (DOY 079/19:00:00 to DOY 086/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1967 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1091 days
Total Mapping Orbits = 13,637
Total Orbits = 15,320

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm162 sequence executed successfully from 02-080 (3/21/02) through 02-082 (3/23/02). The mm163 sequence has performed well since it started on 02-083 (3/24/02). It terminates on 02-086 (3/27/02). The mm164 sequence, successfully uplinked on 02-085 (3/26/02), begins executing on 02-087 (3/28/02).

Other - The Spacecraft team is continuing its intensive analyses of the data leading up to the latest C-mode entry. We know that the root cause of the C-mode entry was that the star processing software (STAREX ) misidentified a star during the initialization cycle following a scale factor update. However, attitude knowledge is being corrupted quicker and to a greater degree than we would expect with a misidentified star. We are continuing our efforts to recreate the C-mode entry in the spacecraft test lab.

Roll Only Targeting Opportunity (ROTO) imaging scans were briefly suspended during the transition to beta-supplement. They will resume on 02-088 (03/29/02) with the mz167 mini-sequence. MGS has completed 234 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 18 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the mm163 and mm164 background sequences. 6,524 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The mm165 background sequence will be uplinked on 02-088 (3/29/02). ROTO mini-sequence mz167 will execute on 02-088 (03/29/02).


Wednesday, March 20, 2002 (DOY 072/19:00:00 to DOY 079/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1960 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1084 days
Total Mapping Orbits = 13,552
Total Orbits = 15,235

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. MGS transitioned to the beta-supplement mode of mapping at the beginning of the MM160A sequence. MM160A started at 02-072 (3/13/02), 23:57 SCET UTC. Since then, the MM160A and MM161C sequences have performed nominally. MM162A starts tonight at 02-079 (3/20/02), 23:57 SCET UTC.

Other - The Spacecraft team is continuing its intensive analyses of the data leading up to the latest C-mode entry. We know that the root cause of the C-mode entry was that the star processing software (STAREX ) misidentified a star during the initialization cycle following a scale factor update. The project has adopted two new flight rules to preclude C-mode entry while the spacecraft team investigates ways of improving STAREX performance. The first rule states that STAREX may not be manually reset or re-enabled unless the AACS mode is "Mapping" or "Sun-Star-Init". It guarantees that MGS will be nadir pointed with the horizon sensor (MHSA) in the attitude control loop, able to provide independent corrections should the spacecraft attitude start drifting because of a misidentified star. The second rule prohibits resetting STAREX at points in the orbit where there are detectable stars within one degree of an on-board swath catalog star. This reduces the risk that STAREX will introduce significant attitude knowledge errors by misidentifying stars due to clustering. Swath star catalogs are created and uplinked to MGS weekly. AACS engineers will now remove stars from the catalogs that exhibit this clustering signature. STAREX only tries to identify stars in its star catalog. Therefore, even though the CSA still detects the star clusters, STAREX will ignore them during star processing because they are no longer in its star catalog.

The solar array positioning command scripts were updated this week to increase the power output of the solar arrays. MGS power margins decrease as it travels toward aphelion. We compensate by reducing the solar array offset angles to maintain an appropriate level of excess power. By effectively regulating excess power, we also extend the life of the Partial Shunt Assemblies.

Roll Only Targeting Opportunity (ROTO) imaging scans were briefly suspended during the transition to beta-supplement. They should resume next week. MGS has completed 234 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 18 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the MM161C and MM162A background sequences, and the new solar array scripts. 6,506 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The mm163 background sequence will be uplinked on 02-081 (3/22/02). ROTO mini-sequence builds should resume next week.


Wednesday, March 13, 2002 (DOY 065/19:00:00 to DOY 072/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1953 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1077 days
Total Mapping Orbits = 13,466
Total Orbits = 15,149

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM159B sequence has performed nominally since it started on 02-065 (3/06/02). It terminates on 02-073 (3/14/02). MM160A starts tonight at 02-072 (3/13/02), 23:57 SCET UTC. It marks the transition from nominal mapping to beta-supplement mapping.

Other - The MGS spacecraft has completely recovered from C-mode. All science instruments are powered and operating nominally. Analysis of playback telemetry confirms that the spacecraft drifted more than 5 degrees following the STAREX reset on on 02-058 (2/27/02), thereby triggering the Sun Monitor Ephemeris fault protection response and subsequent C-Mode entry. The Spacecraft team is continuing its intensive analyses of the playback data.

MGS successfully executed a Roll Only Targeting Opportunity (ROTO) imaging scan on 02-070 (3/11/02) during a scheduled non-comm period. This is significant, as ROTOs performed during the beta-supplement mission phase must occur during non-comm orbits to prevent damaging the HGA. All ROTO events occurred on schedule and gyro biases converged within the hour allocated. MGS has completed 234 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 37 uplinks to the spacecraft during the past week, including miscellaneous C-mode recovery commands, new star catalogs and ephemeris files, instrument power-on commands, instrument command loads, the MM159B and MM160A background sequences, and the MZ166A ROTO mini-sequence. 6,488 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MM160A beta-supplement background sequence will go active today at 2357 SCET UTC. Returning to beta-supplement operations is necessary to avoid the HGA obstruction zone. We enter this mode of operation whenever the Earth Beta Angle decreases to less than 43 degrees.


Wednesday, March 06, 2002 (DOY 058/19:00:00 to DOY 065/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1946 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1070 days
Total Mapping Orbits = 13,381
Total Orbits = 15,064

Recent Events:

Background Sequences
The MM158B background sequence terminated when the spacecraft entered Contingency Mode (C-mode).

At 1854 UTC on 02-058 (2/27/02), we sent commands to update the Y-axis gyro scale factor in order to improve gyro propagation accuracy. Such an update requires cycling the star processing software (STAREX), presenting the small possibility of misidentifying stars as STAREX attempts to converge on a solution. In this case, the number of unidentified stars climbed and spacecraft attitude drifted slightly as MGS approached Earth occultation at 2039 UTC. MGS emerged from Earth occultation at 2112 UTC and the DSN stations detected no signal. The MGS team began recovery procedures.

The MGS spacecraft has been recovered. Analysis of real-time telemetry indicates that the spacecraft drifted more than 5 degrees during the occultation period, thereby triggering the Sun Monitor Ephemeris fault protection response and subsequent C-Mode entry. Future playbacks of the spacecraft data recorded on 02-058 should confirm this scenario.

Presently, MGS is nadir pointed with communications re-established through the high-gain antenna. The team is in the process of completing the C-mode recovery procedure.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 252 uplinks to the spacecraft during the past week, all related to C-mode recovery. 6,451 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MOC and MAG/ER instruments will be powered later today. The MM159B background sequence, soon to be uplinked, will go active today at 2357 SCET UTC. The MOLA and TES instruments will be powered on 02-067 (3/08/02). The MZ066 ROTO mini-sequence executes on 02-070 (3/11/02). On 02-073 (3/14/02), MGS will return to the Beta-Supplement mode of operating in order to avoid the HGA obstruction zone. We enter this mode of operation whenever the Earth Beta Angle decreases to less than 43 degrees.


Wednesday, February 27, 2002 (DOY 051/19:00:00 to DOY 058/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1939 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1063 days
Total Mapping Orbits = 13,295
Total Orbits = 14,978

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM158B sequence has performed nominally since it started on 02-030 (1/30/02). It terminates on 02-058 (2/27/02). MM159A starts tonight at 02-058 (2/28/02), 23:57 SCET UTC.

Other - MGS successfully executed three Roll Only Targeting Opportunity (ROTO) imaging scans in the MZ161 & MZ162 mini-sequences. All ROTO events occurred on schedule and gyro biases converged within the hour allocated. We still see significant attitude corrections following each of the ROTOs. MGS has completed 233 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 20 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mini-sequences referenced above, the MM159 background sequence, and a gyro scale-factor update. 6,199 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will perform more ROTOs in the MZ163 and MZ164 mini-sequences. Another Solar Array and HGA Flexible Modes diagnostic test will be conducted on 02-063 (3/4/02). On 02-073 (3/14/02), MGS will return to the Beta-Supplement mode of operating in order to avoid the HGA obstruction zone. We enter this mode of operation whenever the Earth Beta Angle decreases to less than 43 degrees.


Wednesday, February 20, 2002 (DOY 044/19:00:00 to DOY 051/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1932 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1056 days
Total Mapping Orbits = 13,210
Total Orbits = 14,893

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM158B sequence has performed nominally since it started on 02-030 (1/30/02). It terminates on 02-058 (2/27/02).

Other - MGS successfully executed five Roll Only Targeting Opportunity (ROTO) imaging scans in the MZ160 mini-sequence. All ROTO events occurred on schedule and gyro biases converged within the hour allocated. We still see significant attitude corrections following each of the ROTOs. On 02-042 (2/11/02), we updated the Y-axis gyro low-rate scale factor to reduce gyro propagation errors during ROTOs. We are pleased to see a corresponding 29% reduction in the standard deviation of the bias.
With a sine fit to the bias, we observe a 40% reduction in the amplitude of the variation.
We did not get the expected reduction in the pitch correction. However, this could be due to roll and yaw errors cross coupling into pitch error. MGS has completed 230 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status.

Uplinks:

There have been 7 uplinks to the spacecraft during the past week, including instrument command loads and the ROTO mini-sequences mentioned above. 6,179 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will perform more ROTOs in the MZ161 and MZ162 mini-sequences. Another Solar Array and HGA Flexible Modes diagnostic test will be conducted on 02-063 (3/4/02). On 02-073 (3/14/02), MGS will return to the Beta-Supplement mode of operating in order to avoid the HGA obstruction zone. We enter this mode of operation whenever the Earth Beta Angle decreases to less than 43 degrees.

 


Wednesday, February 13, 2002 (DOY 037/19:00:00 to DOY 044/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1925 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1049 days
Total Mapping Orbits = 13,124
Total Orbits = 14,807

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM158B sequence has performed nominally since it started on 02-030 (1/30/02). It terminates on 02-058 (2/27/02).

Other - MGS successfully executed three Roll Only Targeting Opportunity (ROTO) imaging scans in the MZ158 and MZ159 mini-sequences. All ROTO events occurred on schedule and gyro biases converged within the hour allocated. We still see significant attitude corrections following each of the ROTOs. On 02-042 (2/11/02), we updated the Y-axis gyro low-rate scale factor to reduce gyro propagation errors during ROTOs. We are pleased to see a corresponding 27% reduction in gyro bias variations. We anticipate that the scale factor update will result in smaller attitude corrections in the next series of ROTOs. MGS has completed 225 ROTOs to date.

Spacecraft Health:

All spacecraft subsystems report good health and status. The TES team corrected a couple of TES instrument malfunctions that surfaced recently. The TES is now operating nominally.

Uplinks:

There have been 28 uplinks to the spacecraft during the past week, including instrument command loads, new star catalogs and ephemeris files, a gyro scale-factor update, and the ROTO mini-sequences mentioned above. 6,172 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will perform more ROTOs in the MZ161 and MZ162 mini-sequences.


Wednesday, February 06, 2002 (DOY 030/19:00:00 to DOY 037/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1918 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1042 days
Total Mapping Orbits = 13,039
Total Orbits = 14,722

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM158B sequence has performed nominally since it started on 02-030 (1/30/02). It terminates on 02-058 (2/27/02).

Other - MGS successfully executed three Roll Only Targeting Opportunity (ROTO) imaging scans in the MZ156 and MZ157 mini-sequences. All ROTO events occurred on schedule. Gyro biases converged within the hour allocated. MGS continues to make significant attitude corrections following ROTOs based upon inputs from the MHSA (horizon sensor). AACS engineers are investigating ways to define the gyro biases and scale factors more precisely in order to reduce the attitude errors that accumulate during ROTOs. MGS has completed 222 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. We updated the solar array positioning command scripts this week to increase the power output of the solar arrays. As Mars travels toward aphelion causing MGS power margins to decrease, we reduce solar array offset angles to maintain an appropriate level of excess power. By effectively regulating excess power, we also extend the life of the Partial Shunt Assemblies.

Uplinks:

There have been 19 uplinks to the spacecraft during the past week, including instrument command loads, new star catalogs and ephemeris files, solar array script updates, and the ROTO mini-sequences mentioned above. 6,144 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will perform more ROTOs in the MZ158 and MZ159 mini-sequences.

We will update the Y-axis gyro low-rate scale factor on 02-042 (2/11/02) to reduce the gyro propagation errors we see building during ROTOs.


Wednesday, January 30, 2002 (DOY 023/19:00:00 to DOY 030/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1911 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1035 days
Total Mapping Orbits = 12,953
Total Orbits = 14,636

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM157A sequence has performed nominally since it started on 2002-016 (1/16/02). It terminates on 2002-031 (1/31/02). MM158B starts tonight at 02-030 (1/30/02), 23:57 SCET UTC.

Other - The MZ154 mini-sequence commanded the MOLA back to radiometry mode on 02-024 (1/24/02). It had previously been commanded to normal science mode to check the status of its laser. Unfortunately, the laser is still inoperative.

MGS successfully executed seven Roll Only Targeting Opportunity (ROTO) imaging scans in the MZ152, MZ153, and MZ155 mini-sequences. All ROTO events occurred on schedule. Gyro biases converged between 12 and 46 minutes, within the hour allocated. MGS continues to make significant attitude corrections following ROTOs based upon inputs from the MHSA (horizon sensor). AACS engineers are investigating ways to define the gyro biases and scale factors more precisely in order to reduce the attitude errors that accumulate during ROTOs. MGS has completed 219 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 10 uplinks to the spacecraft during the past week, including instrument command loads, the mini-sequences referenced above, and the MM158 background sequence. 6,125 command files have been radiated to the spacecraft since launch.

Upcoming Events:

More ROTOs will be performed in the MZ156 and MZ157 mini-sequences.


Wednesday, January 23, 2002 (DOY 016/19:00:00 to DOY 023/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1904 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1028 days
Total Mapping Orbits = 12,867
Total Orbits = 14,550

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM157A sequence has performed nominally since it started on 2002-016 (1/16/02). It terminates on 2002-031 (1/31/02).

Other - MGS successfully executed two ROTOS on 2002-016 (1/16/02) and 2002-019 (1/19/02). All ROTO events occurred on schedule. Gyro biases converged at 12 and 39 minutes respectively, well within the hour allocated. MGS continues to make significant attitude corrections following the ROTOs based upon inputs from the MHSA (horizon sensor). The Star Identification Software (SIS) successfully identified all available stars during the gyro-bias convergence process. MGS has completed 212 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 25 uplinks to the spacecraft during the past two weeks, including new star catalog and ephemeris files, instrument command loads, and the MZ151, MZ152, and MZ153 ROTO mini-sequences. 6,115 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MZ152 mini-sequence will perform a ROTO later today and MZ153 will perform a ROTO early tomorrow, 02-024 (1/24/02). At least five more ROTOs will occur this next week in subsequent mini-sequences. Also on 02-024 (1/24/02), the MOLA will be commanded back to radiometry mode with the MZ154 mini-sequence. It was commanded to normal science mode over the weekend to check the status of its laser.


Wednesday, January 16, 2002 (DOY 009/19:00:00 to DOY 016/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1897 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1021 days
Total Mapping Orbits = 12,782
Total Orbits = 14,465

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The MM156A sequence has performed well since it started on 2001-346 (12/12/01). It terminates on 2002-017 (1/17/02). MM157A starts tonight at 01-016 (1/16/02), 23:57 SCET UTC.

Other - While the investigation into MGS star processing difficulties remains ongoing, the Spacecraft Team is focusing primarily on implementing steps to reduce the risk of entering C-mode following ROTOs. We now command MGS to the nadir attitude following each ROTO. While at the nadir attitude, MGS utilizes the MHSA (horizon sensor) to help update its inertial attitude knowledge. After gyro biases successfully converge, MGS returns to the Relay-16 attitude to conserve fuel. MGS successfully executed two ROTOS on 2002-011 (1/11/02) and one ROTO on 2002-015 (1/15/02). All ROTO events occurred on schedule. Gyro biases converged between 9 and 39 minutes, well within the hour allocated. The MHSA allowed MGS to make significant attitude corrections sooner than in the past. Subsequently, the number of misidentified stars remained low following the ROTOs. MGS has completed 210 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 17 uplinks to the spacecraft during the past two weeks, including new star catalog and ephemeris files, instrument command loads, the MM157 background sequence, and the MZ149 and MZ150 ROTO mini-sequences. 6,090 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MZ150 mini-sequence will perform another ROTO later today. More ROTOs will be performed this next week in the upcoming MZ151 and MZ152 mini-sequences.


Wednesday, January 9, 2002 (DOY 002/19:00:00 to DOY 009/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1890 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1014 days
Total Mapping Orbits = 12,696
Total Orbits = 14,379

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. MGS support of Mars Odyssey will end on 2002-011 (1/11/02) with the end of their aerobraking campaign. The MM156A sequence has performed well since it started on 2001-346 (12/12/01). It terminates on 2002-017 (1/17/02).

Other - While the investigation into MGS star processing difficulties remains ongoing, the Spacecraft Team is focusing primarily on implementing steps to reduce the risk of entering C-mode following ROTOs. On 2002-011 (1/11/02) MGS will execute two ROTOs. The most significant change to the ROTO profile is commanding MGS to the nadir attitude following target imaging. While at the nadir attitude, MGS will utilize the MHSA (horizon sensor) to assist in acquiring good inertial attitude knowledge. MGS will then return to the Relay-16 attitude in order to conserve fuel. Relay-16 is an attitude that pitches the spacecraft +16 degrees from nadir to better align its attitude with the gravity gradient, thereby reducing fuel consumption and extending spacecraft life. MGS has completed 207 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 16 uplinks to the spacecraft during the past two weeks, including new star catalog and ephemeris files, and instrument command loads. 6,073 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The mz149b mini-sequence will perform two ROTOs on 02-011 (1/11/02). It implements several changes designed to improve the MGS spacecraft's ability to maintain attitude knowledge following ROTOs.


Wednesday, January 2, 2002 (DOY 353/19:00:00 to DOY 002/19:00:00 UTC)
This report covers two weeks.

Launch / Days since Launch = Nov. 7, 1996 / 1883 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1007 days
Total Mapping Orbits = 12,611
Total Orbits = 14,294

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. MGS support of Mars Odyssey should end by mid-January with the end of their aerobraking campaign. The MM156A sequence has performed well since it started on 2001-346 (12/12/01). It terminates on 2002-017 (1/17/01).

Other - Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during Mars Odyssey aerobraking. The Spacecraft Team continues to investigate MGS difficulties in star processing following slew maneuvers like ROTOs. The team is designing tests and identifying steps needed to mitigate C-mode entry following ROTOs. Some of these steps will be implemented this month, January 2002. The effectiveness of these steps will be assessed during a few specialized ROTOs in January. Our goal is to get back to performing ROTOs routinely with little risk of entering C-mode. MGS has completed 207 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 22 uplinks to the spacecraft during the past two weeks, including new star catalog and ephemeris files, and instrument command loads. 6,057 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will continue to support Odyssey for the remainder of their aerobraking phase. A specialized mini-sequence is being prepared to perform ROTOs by mid-January. It implements several changes designed to improve the MGS spacecraft's ability to maintain attitude knowledge following ROTOs.


Wednesday, December 19, 2001 (DOY 346/19:00:00 to DOY 353/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1869 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 993 days
Total Mapping Orbits = 12,439
Total Orbits = 14,122

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. TES and MOC images are being supplied to the Mars Odyssey team to support their aerobraking campaign. The MM156A sequence has performed well since it started on 2001-346 (12/12/01). It terminates on 2002-017 (1/17/01).

Other - Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during Mars Odyssey aerobraking. The Spacecraft Team continues to investigate MGS difficulties in star processing following slew maneuvers like ROTOs. The team is designing tests and identifying steps needed to mitigate C-mode entry following ROTOs. Some of these steps will be implemented in January 2002. The effectiveness of these steps will be assessed during a few specialized ROTOs in January. MGS has completed 207 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 12 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, and instrument command loads. 6,034 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will continue to support the Odyssey mission during the aerobraking phase by supplying TES and MOC images of the Martian surface. Martian dust storms can bloom into the upper atmosphere, significantly increasing the atmospheric density and posing a threat to Odyssey. The MGS images will provide the Odyssey team the opportunity to avoid potential dust storms. Odyssey should complete the aerobraking phase in mid-January 2002.

 


Wednesday, December 12, 2001 (DOY 339/19:00:00 to DOY 346/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1862 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 986 days
Total Mapping Orbits = 12,354
Total Orbits = 14,037

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. TES and MOC images are being supplied to the Mars Odyssey team to support their aerobraking campaign. The MM155A sequence has performed well since it started on 01-318 (11/14/01). It terminates on 01-347 (12/13/01). MM156A starts tonight at 01-346 (12/12/01), 23:57 SCET UTC.

Other - Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during Mars Odyssey aerobraking. The Spacecraft Team continues to investigate MGS difficulties in star processing following slew maneuvers like ROTOs. The team is designing tests and identifying steps needed to mitigate C-mode entry following ROTOs. MGS has completed 207 ROTOs to date.

The MZ147 High-rate Gyro Data Collection mini-sequence executed successfully on 01-345 (12/11/01). The MZ148 contingency mini-sequence was uplinked, then terminated as planned due to the success of MZ147. The data show that the high-rate gyro bias estimates used during the September and October ROTOs would not have caused the loss of attitude knowledge that resulted in C-mode entry.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 17 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, and the High-rate Gyro Data Collection mini-sequences cited above. 6,022 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will continue to support the Odyssey mission during the aerobraking phase by supplying TES and MOC images of the Martian surface. Martian dust storms can bloom into the upper atmosphere, significantly increasing the atmospheric density and posing a threat to Odyssey. The MGS images will provide the Odyssey team the opportunity to avoid the dust storms if they occur.



Wednesday, December 5, 2001 (DOY 332/19:00:00 to DOY 339/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1855 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 979 days
Total Mapping Orbits = 12,268
Total Orbits = 13,951

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. TES and MOC images are being supplied to the Mars Odyssey team to support their aerobraking campaign. The MM155A sequence has performed well since it started on 01-318 11/14/01). It terminates on 01-347 (12/13/01).

Other - Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during Mars Odyssey aerobraking. The Spacecraft Team continues to investigate MGS difficulties in star processing following slew maneuvers like ROTOs. The team is designing tests and identifying steps needed to mitigate C-mode entry following ROTOs. MGS has completed 207 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. The MZ147 and MZ148 mini-sequences are being developed to collect in-flight data while the gyros are at high-rate. It is possible that some attitude knowledge error is accumulating while the gyros are at high-rate during ROTO slews.

Uplinks:

There have been 10 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, and instrument command loads. 6,005 command files have been radiated to the spacecraft since launch.

Upcoming Events:

The MZ147 and MZ148 High-rate Gyro Data Collection mini-sequences are scheduled to execute 01-345 12/11/01.

MGS will continue to support the Odyssey mission during the aerobraking phase by supplying TES and MOC images of the Martian surface. Martian dust storms can bloom into the upper atmosphere, significantly increasing the atmospheric density and posing a threat to Odyssey. The MGS images will provide the Odyssey team the opportunity to avoid the dust storms if they occur.


Wednesday, November 28, 2001 (DOY 325/19:00:00 to DOY 332/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1848 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 972 days
Total Mapping Orbits = 12,182
Total Orbits = 13,865

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. TES and MOC images are being supplied to the Mars Odyssey team to support their aerobraking campaign. The MM155A sequence has performed well since it started on 01-318 11/14/01). It terminates on 01-347 (12/13/01).

Other - Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during the initial stages of Mars Odyssey aerobraking. The C-Mode investigation continues. Its purpose is to determine the root cause of the latest C-Mode entry and identify risk mitigation steps that will allow MGS to resume ROTO operations during Odyssey aerobraking. MGS has completed 207 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. The spacecraft team is investigating the spacecraft's difficulty in processing stars leading to the C-Mode entry. A mini-sequence is being developed to collect in-flight data while the gyros are at high-rate. It is possible that some attitude knowledge error is accumulating while the gyros are at high-rate during ROTO slews.

Uplinks:

There have been 22 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, and instrument command loads. 5,995 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will continue to support Odyssey during the aerobraking phase of the Odyssey mission by supplying TES and MOC images of the Martian surface. Martian dust storms can bloom into the upper atmosphere, significantly increasing the atmospheric density and posing a threat to Odyssey. The MGS images will provide the Odyssey team the opportunity to avoid the dust storms if they occur.


Wednesday, November 14, 2001 (DOY 311/19:00:00 to DOY 318/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1834 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 958 days
Total Mapping Orbits = 12,011
Total Orbits = 13,694

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. TES and MOC images are being supplied to the Mars Odyssey team to support their aerobraking campaign. The MM154B sequence has performed well since it started on 01-295 10/22/01). It terminates on 01-319 (11/15/01). MM155A starts tonight at 01-318 (11/14/01), 23:57 SCET UTC.

Other - Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during the initial stages of Mars Odyssey aerobraking. The C-Mode investigation continues. Its purpose is to determine the root cause of the latest C-Mode entry and identify risk mitigation steps that will allow MGS to resume ROTO operations during Odyssey aerobraking. MGS has completed 207 ROTOs to date.

The Sun Monitor Ephemeris fault detection was re-enabled with updated parameters. The new parameters will prevent transient shadowing of the sun sensors from triggering C-mode entry and allow additional C-mode protection if attitude knowledge becomes corrupted.

Spacecraft Health:

All subsystems report good health and status. The spacecraft team is investigating the spacecraft's difficulty in processing stars leading to the C-Mode entry.

Uplinks:

There have been 12 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, and the MM155 background sequence. 5,962 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will continue to support Odyssey during the aerobraking phase of the Odyssey mission by supplying TES and MOC images of the Martian surface. Martian dust storms can bloom into the upper atmosphere, significantly increasing the atmospheric density and posing a threat to Odyssey. The MGS images will provide the Odyssey team the opportunity to avoid the dust storms if they occur.


Wednesday, November 7, 2001 (DOY 304/19:00:00 to DOY 311/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1827 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 951 days
Total Mapping Orbits = 11,926
Total Orbits = 13,609

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. TES and MOC images are being supplied to the Mars Odyssey team to support their aerobraking campaign. The MM154B sequence has performed well since it started on 01-295 10/22/01). It terminates on 01-319 (11/15/01).

Other - Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during the initial stages of Mars Odyssey aerobraking. The C-Mode investigation continues. Its purpose is to determine the root cause of the latest C-Mode entry and identify risk mitigation steps that will allow MGS to resume ROTO operations during Odyssey aerobraking. MGS has completed 207 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. The spacecraft team is investigating the spacecraft's difficulty in processing stars leading to the C-Mode entry.

Uplinks:

There have been 19 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, and instrument command loads. 5,950 command files have been radiated to the spacecraft since launch.

Upcoming Events:

MGS will continue to support Odyssey during the aerobraking phase of the Odyssey mission by supplying TES and MOC images of the Martian surface. Martian dust storms can bloom into the upper atmosphere, significantly increasing the atmospheric density and posing a threat to Odyssey. The MGS images will provide the Odyssey team the opportunity to avoid the dust storms if they occur.

Next week the Sun Monitor Ephemeris fault detection will be re-enabled with updated parameters. The new parameters will prevent transient shadowing of the sun sensors from triggering C-mode entry and allow additional C-mode protection if attitude knowledge becomes corrupted.

 


Wednesday, October 3, 2001 (DOY 269/19:00:00 to DOY 276/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1792 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 916 days
Total Mapping Orbits = 11,498
Total Orbits = 13,181

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm153 sequence has performed well since it started 01-256 (9/13/01). It terminates on 01-290 (10/17/01).

Other - Three Roll Only Targeted Observations (ROTOs) were performed this past week. All three occurred during scheduled communications orbits. Previously, MGS had been restricted to performing ROTOs only during non-communications orbits. This new capability of performing ROTOs during communications orbits will allow MGS to perform ROTOs during the Odyssey aerobraking support phase, when MGS has 24 hours of DSN coverage each day. MGS has completed 201 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

The MOLA instrument team has completed their investigation of the MOLA anomaly of 01-181 (6/30/01). The collective results from the instrument tests indicate the anomaly was caused by an interruption of the 100-MHz signal from the precision oscillator in the MOLA altimeter electronics. Without the oscillator signal, the 10-Hz laser trigger signal cannot occur and the laser cannot fire. All testing since July, 2001 shows that the instrument responds properly to commanding and that all other parts of the MOLA are operating normally. The diagnostic tests also demonstrated that the MOLA is fully capable of continuing to collect data in passive radiometer mode.

Uplinks:

There have been 19 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the MZ137 and MZ138 ROTO mini-sequences. 5,790 command files have been radiated to the spacecraft since launch.

Upcoming Events:

A Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline diagnostic test will be performed on 01-278 (10/05/01). It is designated MZ139. Performing this test periodically should give us insight into any additional SA hinge or HGA gimbal degradation, if it occurs.

Five MOC defocus calibrations will be performed between 01-281 (10/8/01) and 01-289 (10/16/01).

A fifth and final MOLA diagnostic test will be conducted on 01-283 (10/10/01) after which the MOLA will be left on to operate in passive radiometer mode.


Wednesday, September 26, 2001 (DOY 262/19:00:00 to DOY 269/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1785 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 909 days
Total Mapping Orbits = 11,412
Total Orbits = 13,095

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm153 sequence has performed well since it started 01-256 (9/13/01). It terminates on 01-290 (10/17/01).

Other - Delta-DOR experiments were performed on 01-267 (9/24/01) and 01-269 (9/26/01).

No Roll Only Targeted Observations (ROTOs) were performed this past week. ROTOs were temporarily suspended pending investigation of the C-Mode entry root cause. MGS entered C-Mode on 9/6/01 because the STAREX star processing software could not converge on a good inertial attitude following a ROTO. The ROTO did not cause the C-Mode entry, but STAREX performance following ROTOs may impact how we perform ROTOs in the future. MGS has completed 198 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. The spacecraft team is investigating ways to improve the probability that STAREX will converge on a good inertial attitude following each ROTO. The MOLA instrument team is still investigating the MOLA anomaly of 01-181 (6/30/01) and will be requesting a fifth diagnostic test in the near future.

Uplinks:

There have been 16 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the MZ136A ROTO mini-sequence. 5,771 command files have been radiated to the spacecraft since launch.

Upcoming Events:

On 01-270 (9/27/01), MGS will perform a ROTO during a communications orbit for the first time. Previously, MGS had been restricted to performing ROTOs only during non-communications orbits. Two more ROTOs during communications orbits are scheduled for the MZ037 mini-sequence.

A Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline diagnostic test will be performed on 01-278 (10/05/01). It is designated MZ139. Performing this test periodically should give us insight into any additional SA hinge or HGA gimbal degradation, if it occurs.


Wednesday, September 19, 2001 (DOY 255/19:00:00 to DOY 262/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1778 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 902 days
Total Mapping Orbits = 11,327
Total Orbits = 13,010

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm153 sequence has performed well since it started 01-156 (9/13/01). It terminates on 01-290 (10/17/01).

Other - MOLA Diagnostic Test #4 was performed on 01-256 (9/13/01). The MOLA team is in the process of analyzing the resulting data.

Roll Only Targeted Observations (ROTO) were temporarily suspended pending investigation of the C-Mode entry root cause. MGS entered C-Mode on 9/6/01 because the STAREX star processing software could not converge on a good inertial attitude following a ROTO. The ROTO did not cause the C-Mode entry, but STAREX performance may impact how we perform ROTOs in the future. MGS has completed 198 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. The spacecraft team continues to investigate the STAREX anomaly that caused the 9/6/01 C-Mode entry. The MOLA instrument team is still investigating the MOLA anomaly of 01-181 (6/30/01). The MOC instrument required a hardware reboot to recover from an anomaly that temporarily prevented it from returning properly formatted science data.

Uplinks:

There have been 28 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, TES instrument turn-on, MOC instrument re-boots, and standard instrument command loads. 5,755 command files have been radiated to the spacecraft since launch.

Upcoming Events:

Delta-DOR experiments are scheduled for 01-267 (9/24/01) and 01-269 (9/26/01).


Wednesday, September 12, 2001 (DOY 248/19:00:00 to DOY 255/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1771 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 895 days
Total Mapping Orbits = 11,241
Total Orbits = 12,924

Recent Events:

Background Sequences - The mm152 background sequence terminated unexpectedly on 01-249 (9/6/01) at 05:34:41 SCET UTC when MGS entered Contingency Mode (C-Mode) due to star processing difficulties. The MGS team has been successful in recovering from C-Mode and playing back the data recorded on 01-248 (9/5/01) and 01-249 (9/6/01) up to the point of C-Mode entry. MGS is presently in the Relay-16 attitude with the MOC and MAG/ER instruments powered back on. MOLA will be powered during the MOLA Diagnostic Test #4 on 01-256 (9/13/01) and TES will be powered on 01-258 (9/15/01). The spacecraft will be operating nominally once the mz153 background sequence goes active later today at 01-155 (9/12/01) 23:59:00.

Other - The Delta-DOR experiment scheduled for 01-253 (9/10/01) and the Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline diagnostic test scheduled for 01-154 (9/11/01) did not take place due to C-Mode recovery.

One Roll Only Targeted Observation (ROTO) was successfully performed before the spacecraft entered C-Mode. MGS has completed 198 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. The spacecraft team is investigating the spacecraft's difficulty in processing stars leading to the C-Mode entry. The MOLA instrument team is still investigating the MOLA anomaly of 01-181 (6/30/01). MOLA Diagnostic Test #4 is scheduled for 01-256 (9/13/01).

Uplinks:

There have been 112 uplinks to the spacecraft during the past week, including C-Mode recovery files, new star catalogs and ephemeris files, instrument command loads, and the MM153 background sequence. 5,727 command files have been radiated to the spacecraft since launch.

Upcoming Events:

Delta-DOR experiments are scheduled for 01-267 (9/24/01) and 01-269 (9/26/01). MOLA Diagnostic Test #4 will take place on 01-156 (9/13/01).


Wednesday, September 05, 2001 (DOY 241/19:00:00 to DOY 248/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1764 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 888 days
Total Mapping Orbits = 11,155
Total Orbits = 12,838

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm152 sequence has performed well since it started on 01-228 (8/16/01). It terminates on 01-255 (9/12/01).

A Delta-DOR experiment was performed on 01-247 (9/4/01).

Other - Fourteen Roll Only Targeted Observations (ROTOs) were successfully performed since the last report. MGS has completed 197 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly. MOLA Diagnostic Test #4 is scheduled for 01-256 (9/13/01).

Uplinks:

There have been 12 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the MZ130 ROTO mini-sequences. 5,615 command files have been radiated to the spacecraft since launch.

Upcoming Events:

Delta-DOR experiments are scheduled for 01-253 (9/10/01), 01-267 (9/24/01), 01-269 (9/26/01).

A Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline diagnostic test will be performed on 01-154 (9/11/01). Performing this test periodically should give us insight into any additional SA hinge or HGA gimbal degradation if it occurs.

MOLA Diagnostic Test #4 will take place on 01-156 (9/13/01).


Wednesday, August 29, 2001 (DOY 234/19:00:00 to DOY 241/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1757 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 881 days
Total Mapping Orbits = 11,070
Total Orbits = 12,753

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm152 sequence has performed well since it started on 01-228 (8/16/01). It terminates on 01-255 (9/12/01).

A Delta-DOR experiment was performed on 01-236 (8/24/01).

Other - Five Roll Only Targeted Observations (ROTOs) were successfully performed since the last report. MGS has completed 183 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.

Uplinks:

There have been 13 uplinks to the spacecraft during the past week, including instrument command loads, and the MZ128 and MZ129 ROTO mini-sequences. Also a new ROTO script was uplinked. It will allow MGS to perform ROTOs during scheduled communications orbits. Previously MGS has been restricted to performing ROTOs only during scheduled non-communications orbits. 5,590 command files have been radiated to the spacecraft since launch.

Upcoming Events:

Delta-DOR experiments are scheduled for 01-247 (9/4/01), 01-253 (9/10/01), 01-267 (9/24/01), 01-269 (9/26/01).

A Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline diagnostic test will be performed on 01-154 (9/11/01). Performing this test periodically should give us insight into any additional SA hinge or HGA gimbal degradation if it occurs.

MOLA Diagnostic Test #4 will take place on 01-156 (9/13/01).


Wednesday, August 15, 2001 (DOY 220/19:00:00 to DOY 227/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1743 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 867 days
Total Mapping Orbits = 10,898
Total Orbits = 12,581

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm151 sequence has performed well since it started on 01-200 (7/19/01). It terminates on 01-227 (8/15/01). The mm152 sequence, successfully uplinked on 01-222 (8/10/01), starts on 01-228 (8/16/01).

Other - On 01-226 (8/14/01), the MGS High Gain Antenna (HGA) signal became erratic and then disappeared at 01-226/13:16, seven minutes before the scheduled Loss of Signal (LOS). The spacecraft team realized that the spacecraft was having difficulty maintaining its attitude due to an expired mapping ephemeris file. They uplinked a new file through the Low Gain Antenna subsequently reacquiring the signal at the scheduled time of 01-226/23:54. Quick coordination by the DSN schedulers and Ops Chief with the Voyager program resulted in an extension to the MGS DSN track. The extension provided the time needed to successfully uplink the new file. Their efforts helped prevent MGS from entering C-Mode, thereby saving valuable science data.

Seven of nine scheduled Roll Only Targeted Observations (ROTOs) were successfully performed since the last report. The last two were aborted during the LOS recovery. MGS has completed 172 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.

Uplinks:

There have been 50 uplinks to the spacecraft during the past week, including LOS recovery commands, new star catalogs and ephemeris files, instrument command loads, command script updates, the mm152 sequence, and the MZ124 and MZ125 ROTO mini-sequences. 5,582 command files have been radiated to the spacecraft since launch.

Upcoming Events:

On 01-228 (8/16/01) the nominal spacecraft orientation will change. The spacecraft will be commanded to pitch +16 degrees from NADIR in order to better align its attitude with the gravity gradient, thereby reducing fuel consumption and extending spacecraft life.

The first of several Delta-DOR experiments will take place on 01-236 (8/24/01).


Wednesday, August 8, 2001 (DOY 213/19:00:00 to DOY 220/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1736 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 860 days
Total Mapping Orbits = 10,813
Total Orbits = 12,496

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm151 sequence has performed well since it started on 01-200 (7/19/01). It terminates on 01-227 (8/15/01).

Other - MGS performed the MZ118 Bistatic Radar experiment on 01-217 (8/5/01) and the MZ121 MOLA Diagnostic Test #3 on 01-218 (8/06/01). The spacecraft operated nominally during both events. The Radio Science and MOLA teams are in the process of analyzing the data collected from their respective experiments. The MOLA team was successful in patching the MOLA software to provide higher sampling rates into the data needed to determine what hardware component failed on 01-181 (6/30/01).

Seven more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 165 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.

Uplinks:

There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the Bistatic Radar and MOLA mini-sequences referenced above, and the MZ122 and MZ123 ROTO mini-sequences. 5,532 command files have been radiated to the spacecraft since launch.

Upcoming Events:

On 01-228 (8/16/01) the nominal spacecraft orientation will change. The spacecraft will be commanded to pitch +16 degrees from NADIR in order to better align its attitude with the gravity gradient, thereby reducing fuel consumption and extending spacecraft life.

The first of several Delta-DOR experiments will take place on 01-236 (8/24/01).


Wednesday, July 25, 2001 (DOY 199/19:00:00 to DOY 206/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1722 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 846 days
Total Mapping Orbits = 10,642
Total Orbits = 12,325

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm151 sequence has performed well since it started on 01-200 (7/19/01). It terminates on 01-227 (8/15/01).

Other - Dust storms spreading across the planet are making narrow angle photographic imaging of Mars impracticable. Therefore, ROTO operations remain suspended until the global dust storms subside. MGS has completed 155 ROTOs to date.

A second in-flight MOLA diagnostic test (MZ116) was performed on 01-206 (7/25/01) to gain more insight into the MOLA anomaly. Detailed analyses will be performed after the recorded data is transmitted to Earth on 01-207 (7/26/01).

Spacecraft Health:

All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.

Uplinks:

There have been 6 uplinks to the spacecraft during the past week, including instrument command loads and the MZ116 MOLA diagnostic test. 5,506 command files have been radiated to the spacecraft since launch.

Upcoming Events:

A Bistatic Radar experiment is planned for 01-217 (8/5/01). The first of several Delta-DOR experiments will take place on 01-236 (8/24/01).


Wednesday, July 18, 2001 (DOY 192/19:00:00 to DOY 199/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1715 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 839 days
Total Mapping Orbits = 10,556
Total Orbits = 12,239

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm150 sequence has performed well since it started on 01-172 (6/21/01). It terminates on 01-199 (7/18/01). The mm151 sequence, successfully uplinked on 01-197 (7/16/01), begins executing on 01-200 (7/19/01).

Other - Dust storms spreading across the planet are making narrow angle photographic imaging of Mars impracticable. Therefore, ROTO operations remain suspended until the global dust storms subside. MGS has completed 155 ROTOs to date.

An in-flight MOLA diagnostic test (MZ115) was performed on 01-195 (7/14/01) to gain some insight into the MOLA anomaly reported last week. Unfortunately, the MOLA instrument did not assume normal operation, but the data indicate that the MOLA computer is working and that the instrument responds to commanding. We expect further diagnostic testing following the MOLA team's analyses of the most recent data.

Spacecraft Health:

All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.

Uplinks:

There have been 13 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the MM151 background sequence, and the MZ115 MOLA diagnostic test. 5,500 command files have been radiated to the spacecraft since launch.

Upcoming Events:

A Bistatic Radar experiment is planned for 01-217 (8/5/01). The first of several Delta-DOR experiments will take place on 01-236 (8/24/01).


Wednesday, June 27, 2001 (DOY 171/19:00:00 to DOY 178/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1694 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 818 days
Total Mapping Orbits = 10,299
Total Orbits = 11,982

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm150 sequence has performed well since it started on 01-172 (6/21/01). It terminates on 01-199 (7/18/01).

Other - An MGS Mars Relay On-orbit UHF experiment with Stanford University started on 01-177 (6/26/01) and finishes on 01-179 (6/28/01). So far, the experiment has progressed nominally. A more detailed report will be forthcoming following the data analyses.

Eight more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 145 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mz112 UHF Relay-16 experiment, and ROTO mini-sequences mz111 & mz113. There have been 5,466 command files radiated to the spacecraft since launch.

Upcoming Events:

MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01). A Bistatic Radar Test is planned for 01-217 (8/5/01). More MOLA Polar Scans are scheduled for 01-219 (8/7/01) and 01-220 (8/8/01). Finally, the first of several Delta-DOR experiments will take place on 01-225 (8/13/01).


Wednesday, June 20, 2001 (DOY 164/19:00:00 to DOY 171/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1687 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 811 days
Total Mapping Orbits = 10,214
Total Orbits = 11,897

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm148 sequence executed successfully from 01-165 (6/14/01) through 01-167 (6/16/01). The mm149 sequence has performed well since it started on 01-168 (6/17/01). It terminates on 01-171 (6/20/01). The mm150 sequence, successfully uplinked on 01-170 (6/19/01), begins executing on 01-172 (6/21/01). The start of mm150 marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Therefore, background command sequences can take advantage of the on-board command scripts originally designed for the nominal mapping mission. 28-day background sequences will become the norm instead of the 3 and 4 day beta-supplement sequences.

Other - Eleven more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 137 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 12 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz109 & mz110. We also updated Solar Array AEM Script #1 timing to avoid potential electromagnetic interference (EMI) with the solar arrays during HGA transmissions to Earth. There have been 5,449 command files radiated to the spacecraft since launch.

Upcoming Events:

Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-179 (6/28/01). MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01).


Wednesday, June 13, 2001 (DOY 157/19:00:00 to DOY 164/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1680 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 804 days
Total Mapping Orbits = 10,129
Total Orbits = 11,812

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm146 sequence executed successfully from 01-158 (6/7/01) through 01-160 (6/09/01). The mm147 sequence has performed well since it started on 01-161 (6/10/01). It terminates on 01-164 (6/13/01). The mm148 sequence, successfully uplinked on 01-163 (6/12/01), begins executing on 01-165 (6/14/01).

Other - Nine more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 126 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

Uplinks:

There have been 18 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequences mz107 & mz108. There have been 5,437 command files radiated to the spacecraft since launch.

Upcoming Events:

DOY 01-172 (6/21/01) marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Nominal mapping sequences will not be as command intensive as the beta-supplement sequences. Therefore, 28-day background sequences will be the norm instead of the 3 and 4 day beta-supplement sequences.

Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-179 (6/28/01). MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01).


Wednesday, June 6, 2001 (DOY 150/19:00:00 to DOY 157/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1673 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 797 days
Total Mapping Orbits = 10,043
Total Orbits = 11,726

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm144 sequence executed successfully from 01-151 (5/31/01) through 01-153 (6/02/01). The mm145 sequence has performed well since it started on 01-154 (6/03/01). It terminates on 01-157 (6/06/01). The mm146 sequence, successfully uplinked on 01-156 (6/05/01), begins executing on 01-158 (6/07/01).

Other - Ten more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 117 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

The Sun Monitor Ephemeris fault protection is disabled to prevent another C-Mode entry due to sun-sensor shadowing by the HGA. Sun-sensor shadowing is the most likely cause of the 5/2/01 entry into C-Mode. The shadowing was caused by a combination of planetary geometry and beta-supplement HGA positioning. The 35 degree Solar Panel offpoint caused the SAM sun-sensor instead of the SAP sun-sensor to be selected for sensing sun position. Flight software could not accurately compute sun position when the SAM sun-sensor became shadowed by the HGA. Other fault protection routines continue to protect MGS from losing its attitude knowledge.

Uplinks:

There have been 13 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz104, mz105, & mz106. There have been 5,419 command files radiated to the spacecraft since launch.

Upcoming Events:

DOY 01-172 (6/21/01) marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Nominal mapping sequences will not be as command intensive as the beta-supplement sequences. Therefore, 28-day background sequences will be the norm instead of the 3 and 4 day beta-supplement sequences.

Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-179 (6/28/01). MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01).


Wednesday, May 30, 2001 (DOY 143/19:00:00 to DOY 150/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1666 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 790 days
Total Mapping Orbits = 9,957
Total Orbits = 11,640

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm142 sequence executed successfully from 01-144 (5/24/01) through 01-146 (5/26/01). The mm143 sequence has performed well since it started on 01-147 (5/27/01). It terminates on 01-150 (5/30/01). The mm144 sequence, successfully uplinked on 01-149 (5/29/01), begins executing on 01-151 (5/31/01).

Other - Nine more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 107 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

The Sun Monitor Ephemeris fault protection continues to be disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.

Uplinks:

There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequence mz103.

Three solar array position management scripts were updated to offset the commanded solar array positions by 35 degrees instead of the previous offset of 25 degrees. The update should extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays

There have been 5,406 command files radiated to the spacecraft since launch.

Upcoming Events:

DOY 01-172 (6/21/01) marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Nominal mapping sequences will not be as command intensive as the beta-supplement sequences. Therefore, 28-day background sequences will be the norm instead of the 3 and 4 day beta-supplement sequences.

Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-180 (6/29/01).


Wednesday, May 23, 2001 (DOY 136/19:00:00 to DOY 143/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1659 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 783 days
Total Mapping Orbits = 9,871
Total Orbits = 11,554

Recent Events:

Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm140 sequence executed successfully from 01-137 (5/17/01) through 01-139 (5/19/01). The mm139 sequence has performed well since it started on 01-140 (5/20/01). It terminates on 01-143 (5/23/01). The mm142 sequence, successfully uplinked on 01-142 (5/22/01), begins executing on 01-144 (5/24/01).

Other - Eleven more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 98 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. All science instruments have been powered-on. The TES was powered-up on 01-138 (5/18/01).

The Sun Monitor Ephemeris fault protection continues to be disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.

Uplinks:

There have been 15 uplinks to the spacecraft during the past week, including the TES power-on command file, instrument command loads, the background sequences cited above, and ROTO mini-sequences mz100b, mz101, and mz102. There have been 5,389 command files radiated to the spacecraft since launch.

Upcoming Events:

Within the next week, we will update the three solar array position management scripts to offset the commanded solar array positions by 35 degrees instead of the present offset of 25 degrees. This update is needed to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays.

Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-180 (6/29/01).


Wednesday, May 16, 2001 (DOY 129/19:00:00 to DOY 136/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1652 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 776 days
Total Mapping Orbits = 9,786
Total Orbits = 11,469

Recent Events:

Background Sequences - Except for the TES being off, the spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm138 sequence executed successfully from 01-130 (5/10/01) through 01-132 (5/12/01). The mm139 sequence has performed well since it started on 01-133 (5/13/01). It terminates on 01-136 (5/16/01). The mm140 sequence, successfully uplinked on 01-135 (5/15/01), begins executing on 01-137 (5/17/01).

Other - Twelve Radio Science Occultation Egress Scans contained in the mz097 mini-sequence were successfully performed on 01-133 (5/13/01) and 01-134 (5/14/01). An MGS Mars Relay On-orbit UHF Test, initiated by the Mars Exploration Rover project, was conducted successfully with Stanford University on 01-135 (5/15/01) and 01-136 (5/16/01). Three more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 87 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. All science instruments have been powered-on except the TES. During C-Mode recovery, the TES was powered-on, then off when it did not respond correctly to the NIPC commands prepared by the TES Team. The TES team determined the problem to be with the NIPC file itself and not the with the TES instrument. The TES will be powered-up on 01-138 (5/18/01).

The Sun Monitor Ephemeris fault protection continues to be disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.

Uplinks:

There have been 22 uplinks to the spacecraft during the past week, including three C-Mode recovery clean-up commands, new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, the mz097 Radio Science mini-sequence, and ROTO mini-sequences mz099 and mz100. There have been 5,374 command files radiated to the spacecraft since launch.

Upcoming Events:

The Thermal Emission Spectrometer will be powered-up on 01-138 (5/18/01). Within the next few weeks, we will update the three solar array position management scripts to offset the commanded solar array positions by 35 degrees instead of the present offset of 25 degrees. This update is needed to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays.

Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-180 (6/29/01).


Wednesday, May 9, 2001 (DOY 122/19:00:00 to DOY 129/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1645 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 769 days
Total Mapping Orbits = 9,701
Total Orbits = 11,384

Recent Events:

Background Sequences - There have been no background sequences operating since MGS entered C-Mode a week ago on 01-122 (5/02/01). Last week, the mm135 sequence terminated approximately fourteen hours earlier than expected due to C-Mode entry. The mm136 sequence, though uplinked, was prevented from starting on 01-123 (5/3/01) by C-Mode. The mm137 sequence was never uplinked. Recovery efforts have gone well the past two days and we expect to start normal background sequencing with mm138. It will start today, 01-129 (5/9/01), at 23:57:00 UTC Spacecraft Event Time. mm139 is scheduled for uplink on 01-131 (5/11/01). It will commence on 01-133 (5/13/01).

Other - No ROTOs or other special science scans were conducted this week. The mz095 mini-sequence was used to return MGS to its normal NADIR pointing attitude. It also triggered an on-board command script to control movement of the HGA and operate the downlink transmitter during the transition from C-Mode to nominal mapping. The mz096 mini-sequence was prepared in the optimistic hope that we might recover in time to conduct a ROTO. It was never uplinked due to the intense effort required to prepare and uplink the C-Mode recovery command files. The mz098 mini-sequence was uplinked today to terminate the HGA command script shortly before the mm138 background sequence goes active.

Spacecraft Health:

All subsystems report good health and status. All science instruments have been powered-on except the TES. The TES was powered-on, then off when it did not respond correctly to the NIPC commands prepared by the TES Team. The TES team suspects that the problem may be with the NIPC file itself and not the with the TES instrument.

The Sun Monitor Ephemeris fault detection and response have been disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.

Uplinks:

There have been 66 C-Mode recovery uplinks to the spacecraft during the past week. There have been 5,352 command files radiated to the spacecraft since launch.

Upcoming Events:

The Radio Science Occultation Egress Scans contained in the mz097 mini-sequence should take place as scheduled on 01-133 (5/13/01) and 01-134 (5/14/01). An MGS Mars Relay On-orbit UHF Test, initiated by the Mars Exploration Rover project, will be conducted with Stanford University on 01-135 (5/15/01) and 01-136 (5/16/01).


Wednesday, May 2, 2001 (DOY 115/19:00:00 to DOY 122/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1638 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 762 days
Total Mapping Orbits = 9,615
Total Orbits = 11,298

Recent Events:

Background Sequences -- The spacecraft is now in Contingency Mode (C-Mode), so background sequence processing has terminated until the Spacecraft Team intervenes. The mm134 sequence executed successfully from 01-116 (4/26/01) through 01-118 (4/28/01). The mm135 sequence performed well from the time it started on 01-119 (4/29/01) until it terminated on 01-122 (5/02/01) at 10:10:55 Spacecraft Event Time (SCET) with a C-Mode entry. The mm136 sequence, successfully uplinked on 01-121 (5/01/01), was to begin executing on 01-123 (5/03/01), but will not due to the C-Mode entry.

Other - MGS transmitted high frequency spacecraft body rate data to Earth on 01-115 (4/25/01). The data will provide insight into the health of the -Y solar array hinge and the effects of solar array motion on TES data. Four of five MOC Defocus Calibration Scans were performed by the mm134 and mm135 sequences before C-Mode was entered. The fifth scan may be made-up at some future date. All four ROTOs contained in the mz093 mini-sequence were performed. The mz094 mini-sequence, containing five ROTOs, will not be uplinked due to C-Mode recovery. MGS has performed 84 Roll Only Targeted Observations to date.

Spacecraft Health:

All subsystems report good health and safe status consistent with C-Mode entry. Downlink telemetry is consistent with the following C-Mode state: Spacecraft coning about the sun with the solar arrays automatically tracking the sun and generating adequate power; HGA "frozen" in the position it was in when the spacecraft entered C-Mode; 7.8125 bps uplink and 10 bps downlink communications provided through the LGA; science instruments powered off.

MGS project engineers have initiated the C-Mode Recovery Plan.

We know that the Sun Monitor Ephemeris fault response sent MGS into C-Mode but we do not know why. The spacecraft continually compares the sun position calculated from on-board sun sensors to the expected sun position provided by the Spacecraft Team. When the two positions diverge greater that five degrees for greater than two seconds, the Sun Monitor Ephemeris fault response initiates C-Mode.

Uplinks:

There have been 16 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequence mz093.

There have been 5,286 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm137 background sequence will not be uplinked on 01-124 (5/04/01) because we are recovering from C-mode. If the recovery effort goes well, background sequence processing will start with mm138. Radio Science Occultation Egress Scans are scheduled for 01-133 (5/13/01) and 01-134 (5/14/01). An MGS Mars Relay On-orbit UHF Test, initiated by the Mars Exploration Rover project, will be conducted with Stanford University on 01-135 (5/15/01) and 01-136 (5/16/01).


Wednesday, April 25, 2001 (DOY 108/19:00:00 to DOY 115/19:00:00 UTC)
This report covers two weeks.

Launch / Days since Launch = Nov. 7, 1996 / 1631 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 755 days
Total Mapping Orbits = 9,530
Total Orbits = 11,213

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm132 sequence executed successfully from 01-109 (4/19/01) through 01-111 (4/21/01). The mm133 sequence has performed well since it started on 01-112 (4/22/01). It terminates on 01-115 (4/25/01). The mm134 sequence, successfully uplinked on 01-114 (4/24/01), begins executing on 01-116 (4/26/01).

Other - MGS transmitted high frequency spacecraft body rate data to Earth on 01-115 (4/25/01). The data will provide insight into the health of the -Y solar array hinge and the effects of solar array motion on TES data. MGS has performed 75 Roll Only Targeted Observations to date.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 12 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz091 through mz092.

The last two of three solar array position management scripts were modified to offset the commanded solar array positions by 25 degrees. Our goal is to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays.

There have been 5,270 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm135 background sequence will be uplinked on 01-117 (4/27/01). MOC Defocus Calibration Scans will be performed by the mm134 and mm135 sequences between 01-116 (4/26/01) and 01-123 (5/02/01). Radio Science Occultation Egress Scans are scheduled for 01-132 (5/12/01) and 01-133 (5/13/01). ROTO mini-sequences mz092 and mz093 will execute this next week.


Wednesday, April 18, 2001 (DOY 094/19:00:00 to DOY 108/19:00:00 UTC)

This report covers two weeks.

Launch / Days since Launch = Nov. 7, 1996 / 1624 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 748 days
Total Mapping Orbits = 9,444
Total Orbits = 11,127

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm128, mm129, and mm130 sequences executed successfully from 01-095 (4/05/01) through 01-104 (4/14/01). The mm131 sequence has performed well since it started on 01-105 (4/15/01). It terminates on 01-108 (4/18/01). The mm132 sequence, successfully uplinked on 01-107 (4/17/01), begins executing on 01-109 (4/19/01).

Other - MGS successfully performed twelve Radio Science Occultation Egress Scans on 01-095 (4/5/01) and 01-096 (4/6/01). They were contained in the mz085 mini-sequence. MGS has performed 65 Roll Only Targeted Observations to date.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 30 uplinks to the spacecraft during the past two weeks, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, a thruster accumulator reset command, and ROTO mini-sequences mz086 through mz090.

Commands were uplinked to modify the Reaction Wheel Assembly fault protection software and associated scripts. The modified response will allow a quicker recovery should another reaction wheel fail.

The first of three solar array position management scripts was modified to offset the commanded solar array positions by 25 degrees. Our goal is to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays. We will update the other two scripts after verifying the expected spacecraft performance under the first script.

There have been 5,258 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm133 background sequence will be uplinked on 01-110 (4/20/01). On 01-115 (4/25/01) of that sequence, MGS will transmit high frequency spacecraft body rate data to Earth. The data will provide insight into the health of the -Y solar array hinge and the effects of solar array motion on TES data. MOC Defocus Calibration Scans will be performed by the mm134 and mm135 sequences between 01-116 (4/26/01) and 01-123 (5/02/01). Radio Science Occultation Egress Scans are scheduled for 01-132 (5/12/01) and 01-133 (5/13/01).

ROTO mini-sequences mz090 and mz091 will execute this next week.


Wednesday, April 04, 2001 (DOY 087/19:00:00 to DOY 094/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1610 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 734 days
Total Mapping Orbits = 9,272
Total Orbits = 10,955

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm126 sequence executed successfully from 01-088 (3/29/01) through 01-090 (3/31/01). The mm127 sequence has performed well since it started on 01-091 (4/01/01). It terminates on 01-094 (4/04/01). The mm128 sequence, successfully uplinked on 01-093 (4/03/01), begins executing on 01-095 (4/05/01).

Other - MGS performed 6 Roll Only Targeted Observations since the last status report, bringing the total number of ROTOs to 46.

Spacecraft Health:

All subsystems report nominal health.

Uplinks: There have been 15 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, ROTO mini-sequence mz084, and Radio Science Occultation Egress Scan mini-sequence mz085. There have been 5,228 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm129 background sequence will be uplinked on 01-096 (4/06/01). ROTO mini-sequences mz086 and mz087 will be uplinked and executed this next week. Radio Science Occultation Egress Scans, contained in the mz085 mini-sequence, will take place on 01-095 (4/5/01) and 01-096 (4/6/01).


Wednesday, March 28, 2001 (DOY 080/19:00:00 to DOY 087/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1603 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 727 days
Total Mapping Orbits = 9,162
Total Orbits = 10,845

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm124 sequence executed successfully from 01-081 (3/22/01) through 01-083 (3/24/01). The mm125 sequence has performed well since it started on 01-084 (3/25/01). It terminates on 01-087 (3/28/01). The mm126 sequence, successfully uplinked on 01-086 (3/27/01), begins executing on 01-088 (3/29/01).

Other - On 01-082 (3/23/01), the mz081 Relay-22 mini-sequence commanded MGS to a more fuel-efficient attitude by inducing a +22 degree Pitch offset. The spacecraft maintained this attitude for approximately eight hours. The data collected helped characterize the thermal, momentum buildup, fuel usage, and Starex processing profiles of the spacecraft in the new attitude.

During the Relay-22 Demo, Thermal subsystem performance was nominal. The predicted temperature response agreed well with the observed data. Temperature changes were generally small with the single exception of the MOC secondary mirror, which showed a 5°C temperature increase as predicted. This increase is not a concern. There are no thermal issues for the expected final pitch angle of somewhat less than 22 degrees.

Attitude Control also looked nominal but requires more investigation since the MOC team reported Roll offpoints large enough to be noticed by their instrument. The spin momentum buildup rate was -0.5 Nms/hr, which would result in an unload event every 18 hours vs. the present 7.5 hours. Adjusting current fuel use to the new rate of spin momentum buildup, we estimate the daily fuel use for the new configuration to be approximately 15 g/day (11 g/day spin, 4 g/day yaw). This represents approximately half the fuel consumption of the nominal attitude profile. We anticipate a Pitch offset near 16 degrees to be near optimum. As expected, there was no noticeable change in the Yaw momentum buildup rate. Starex performed nominally, converging in 11 stars. No major changes in gyro biases (versus nominal) were observed.

We were unable to collect high frequency body rate data because of a subtle error in the way the Solid State Recorders were commanded. We expect to collect this data in the near future in order to diagnose the health of the -Y solar array hinge. The data will also help us determine what effect solar array motion has on TES instrument data.

The Power subsystem performed nominally during the Relay-22 Demonstration.

Three new Solar Array Autonomous Eclipse Management scripts were loaded into memory this week. They will go active on 01-088 (3/29/01), returning Solar Array management from a 4-motion strategy to a 3-motion strategy. This may extend the life of the solar array gimbals and may reduce solar array noise effects upon the TES data.

MGS performed 4 Roll Only Targeted Observations since the last status report, bringing the total number of ROTOs to 40.

Spacecraft Health:

All subsystems report nominal health.

Uplinks: There have been 13 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, ROTO mini-sequences mz082 and mz083, and three modified Solar Array Autonomous Eclipse Management scripts. There have been 5,213 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm127 background sequence will be uplinked on 01-089 (3/30/01). ROTO mini-sequences mz084 and mz085 will be uplinked and executed this next week. Radio Science Occultation Egress Scans, contained in the mz085 mini-sequence, will take place on 01-095 (4/5/01) and 01-096 (4/6/01).



Wednesday, March 21, 2001 (DOY 073/19:00:00 to DOY 080/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1596 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 720 days
Total Mapping Orbits = 9,102
Total Orbits = 10,785

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm122 sequence executed successfully from 01-074 (3/15/01) through 01-076 (3/17/01). The mm123 sequence has performed well since it started on 01-077 (3/18/01). It terminates on 01-080 (3/21/01). The mm124 sequence, successfully uplinked on 01-079 (3/20/01), begins executing on 01-081 (3/22/01).

Other - MGS performed 10 Roll Only Targeted Observations since the last status report, bringing the total number of ROTOs to 36.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 10 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, the ROTO mini-sequence mz080, and the Relay-22 Demo mini-sequence mz081. There have been 5,200 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm125 background sequence will be uplinked on 01-082 (3/23/01). ROTO mini-sequences mz082 and mz083 will be uplinked and executed this next week. On 01-082 (3/23/01), the mz081 mini-sequence will command MGS to a more fuel-efficient attitude for approximately four hours. The data collected during this demonstration will allow us to characterize the thermal, momentum buildup, fuel usage, and Starex processing profiles of the spacecraft in the new attitude. We will also gather high frequency body rate data to diagnose the health of the -Y solar array hinge. This knowledge will help us plan for future mission activities.


Wednesday, March 14, 2001 (DOY 066/19:00:00 to DOY 073/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1589 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 713 days
Total Mapping Orbits = 9,016
Total Orbits = 10,699

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm120 sequence executed successfully from 01-067 (3/08/01) through 01-069 (3/10/01). The mm121 sequence has performed well since it started on 01-070 (3/11/01). It terminates on 01-073 (3/14/01). The mm122 sequence, successfully uplinked on 01-072 (3/13/01), begins executing on 01-074 (3/15/01).

Other - MGS performed 9 Roll Only Targeted Observations since the last status report, bringing the total number of ROTOs to 26.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 20 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequences mz077 and mz078. There have been 5,190 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm123 background sequence will be uplinked on 01-075 (3/16/01). ROTO mini-sequences mz079 and mz080 will be uplinked and executed this next week. On 01-082 (3/23/01), the mz081 mini-sequence will command MGS to a more fuel-efficient attitude for approximately four hours. The data collected during this demonstration will allow us to characterize the thermal, momentum buildup, fuel usage, and Starex processing profiles of the spacecraft in the new attitude. We will also gather high frequency body rate data to diagnose the health of the -Y solar array hinge. This knowledge will help us plan for future mission activities.


Wednesday, March 7, 2001 (DOY 059/02:00:00 to DOY 066/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1582 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 706 days
Total Mapping Orbits = 8,930
Total Orbits = 10,613

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm118 sequence executed successfully from 01-060 (3/01/01) through 01-062 (3/03/01). The mm119 sequence has performed well since it started on 01-063 (3/04/01). It terminates on 01-066 (3/07/01). The mm120 sequence, successfully uplinked on 01-065 (3/06/01), begins executing on 01-067 (3/08/01).

Other - MGS performed 11 Roll Only Targeted Observations since the last status report, bringing the total number of ROTOs to 17.

A flight software patch to the Safe Mode code was uplinked on 01-060 (3/01/01). The purpose of this patch is to prevent the HGA from entering the HGA exclusion zone during a Safe Mode entry. The patch reduces HGA risk and allows increased SSR playback time or increased real-time data transmission during every communications orbit.

A parameter update was uplinked on 01-064 (3/05/01) to ensure entry into the Safe Mode response if another RWA failure occurs.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 26 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, the Safe Mode patch and parameter update, and ROTO mini-sequences mz075 and mz076. There have been 5,170 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm121 background sequence will be uplinked on 01-068 (3/09/01). ROTO mini-sequences mz077 and mz078 will be uplinked and executed this next week.


Wednesday, February 28, 2001 (DOY 052/19:00:00 to DOY 059/02:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1575 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 699 days
Total Mapping Orbits = 8,836
Total Orbits = 10,519

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm116 sequence executed successfully from 01-053 (2/22/00) through 01-055 (2/24/01). The mm117 sequence has performed well since it started on 01-056 (2/25/01). It terminates on 01-059 (2/28/01). The mm118 sequence, successfully uplinked on 01-058 (2/27/01), begins executing on 01-060 (3/01/01).

Other - MGS performed five Roll Only Targeted Observations since the last status report, bringing the total number of ROTOs to six.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 9 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz073 and mz074. There have been 5,144 command files radiated to the spacecraft since launch.

Upcoming Events:

A flight software patch to the Safe Mode code will be uplinked on 01-060 (3/01/01). The purpose of this patch is to prevent the HGA from entering the HGA exclusion zone during a Safe Mode entry. Presently, when the S/C enters Safe Mode, the HGA automatically slews directly to a predetermined target position. Unfortunately, this type of slew poses a risk in some cases due to the HGA gimbal obstruction. It is possible that the HGA could drive through the HGA exclusion zone on its way to the target position. The project has mitigated this risk to date by building background sequences that avoid commanding the HGA into potentially hazardous positions. The unfortunate trade-off has been reduced communications time each orbit. The HGA Safe Mode software patch causes the HGA to "freeze" its position upon Safe Mode entry. Consequently, the project regains communications time every orbit by moving the risk mitigation from nominal sequencing to the Safe Mode fault response.

The mm119 background sequence will be uplinked on 01-061 (3/02/01). ROTO mini-sequences mz075 and mz076 will be uplinked and executed this next week.


Wednesday, February 21, 2001 (DOY 045/19:00:00 to DOY 052/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1568 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 692 days
Total Mapping Orbits = 8,759
Total Orbits = 10,442

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm114 sequence executed successfully from 01-046 (2/15/00) through 01-048 (2/17/01). The mm115 sequence has performed well since it started on 01-049 (2/18/01). It terminates on 01-052 (2/21/01). The mm116 sequence, successfully uplinked on 01-051 (2/20/01), begins executing on 01-053 (2/22/01).

Other - MGS performed flawlessly during the Roll Only Targeted Observation demonstration executed on orbit #8690 of 01-047 (2/16/00). Post-test analyses of the engineering data verified nominal performance by all subsystems.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 6 uplinks to the spacecraft during the past week, including instrument command loads and the background sequences cited above. There have been 5,135 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm117 background sequence will be uplinked on 01-054 (2/23/01). Because the ROTO demonstration was successful, standard procedure will be to uplink two ROTO mini-sequences each week. The ROTO mini-sequences for this next week are mz073 and mz074.


Wednesday, February 7, 2001 (DOY 031/19:00:00 to DOY 038/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1554 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 678 days
Total Mapping Orbits = 8,575
Total Orbits = 10,258

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm110 sequence executed successfully from 01-032 (2/1/00) through 01-034 (2/3/01). The mm111 sequence has performed well since it started on 01-035 (2/4/01). It terminates on 01-038 (2/7/01). The mm112 sequence, successfully uplinked on 01-037 (2/6/01), begins executing on 01-039 (2/08/01).

Other - Another successful DDOR experiment was performed on 01-034 (2/3/01) as part of the mm110 background sequence.

Spacecraft Health:

All subsystems report nominal health. Investigation into the root cause of the X-axis Reaction Wheel failure continues. Although we are confident that a short circuit within the RWA-X electronics caused the failure, isolating the exact piece-part that failed seems unlikely. Work continues in identifying operational impacts associated with using RWA-S for attitude control. We are also investigating methods of protecting the spacecraft against a second RWA failure.

Uplinks:

There have been 16 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. We also increased the Momentum Unload Give Up Timer to 120 minutes so that manually induced momentum unloads do not terminate prematurely due to worst-case phasing errors. (See the 1/24/01 MGS Status Report) Finally, we reset the Audit Queue Counter to a value consistent with the Audit Queue activity that occurred since the counter reached its maximum value of 255. This particular counter does not rollover automatically and must be reset with a ground command when it reaches its maximum value. There have been 5,113 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm113 background sequence will be uplinked on 01-040 (2/09/01). Development of the mz072 Roll Only Targeted Observation (ROTO) Demonstration mini-sequence will commence on 01-043 (2/12/01).


Wednesday, January 24, 2001 (DOY 017/19:00:00 to DOY 024/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1540 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 664 days
Total Mapping Orbits = 8,416
Total Orbits = 10,099

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm106 sequence executed successfully from 01-018 (1/18/00) through 01-020 (1/20/01). The mm107 sequence has performed well since it started on 01-021 (1/21/01). It terminates on 01-024 (1/24/01). The mm108 sequence, successfully uplinked on 01-023 (1/23/01), begins executing on 01-025 (1/25/01).

Other - Two unrelated spacecraft anomalies occurred on 01-018 (1/18/91).

The first anomaly occurred within the first two hours of 01-018 (1/18/91). A Yaw Axis momentum unload terminated prematurely, failing to completely unload Z-Axis momentum to 1.0 Nms. Instead, the momentum unload terminated at 2.5 Nms. This required flight software to immediately command another Yaw Axis momentum unload to complete the task of reaching 1.0 Nms. Subsequent analysis revealed that the unload was prematurely terminated by the "give up" timer used to prevent unloads from persisting beyond the time span allowed. The Yaw unload in question was induced by the mz070 MOLA Polar Scan mini-sequence. Commands within the mini-sequence lowered the unload threshold to 2.0 Nms in order to dump momentum before the MOLA Polar Scans began. This routine procedure was required because MOLA Polar Scans do not allow proper Yaw momentum unloading. Unfortunately, the timing of the induced unload was out-of-phase with the momentum profile for that particular orbit. Flight software waited appropriately until the unload could be accomplished in-phase with the momentum profile. However, the delay stretched the execution of the unload beyond the established "give up" boundary and the unload terminated early. Flight software responded appropriately throughout this scenario, eventually reducing the Z-Axis momentum to 1.0 Nms without ground intervention. The MOLA Polar scans for the subsequent three orbits executed nominally. Corrective action to increase the "give-up" timer parameter is in work to ensure that future momentum unloads do not terminate prematurely due to worst-case phasing errors.

The second anomaly involved a hardware failure on 01-018 (1/18/01). At approximately 15:35:43 Spacecraft Event Time (SCET) Universal Time Coordinated (UTC), the X-axis Reaction Wheel Assembly (RWA-X) failed. Redundancy Management (REDMAN) code within flight software reacted appropriately by switching X-axis attitude control to the redundant "Skew" Reaction Wheel Assembly (RWA-S). Stored-sequence command processing proceeded nominally, allowing MGS to continue mapping without interruption. A command was uplinked on 01-019 (1/19/01) to terminate the mz070 mini-sequence, thereby ensuring the MOLA Polar Scans would not occur until the anomaly was understood. On 01-020 (1/20/91), a command was uplinked to keep RWA-S reaction wheel speeds within comfotable limits by reducing the nominal Yaw Axis momentum unload threshold from 10 Nms to 6 Nms. The mz071C mini-sequence was uplinked and executed on 01-024 (1/24/91) to determine the future availability of RWA-X. RWA-X did not respond during the 20-second test, verifying that it had failed. The spacecraft team is continuing its probe into the probable root cause(s) of the failure. The leading theory is that a component failed in the RWA-X electronics. Our goal is to determine the most probable root cause(s) of the failure so that we can adequately maintain spacecraft health and capability to achieve extended mission objectives. Meanwhile, the MGS spacecraft is operating as designed on the redundant reaction wheel.

One Delta Differential One-Way Range (DDOR) experiment was conducted on 01-024 (1/24/01).

Spacecraft Health:

RWA-X has failed, forcing the Attitude and Articulation Control Subsystem (AACS) to operate on the redundant "skew" reaction wheel for attitude control about the X-axis. The Electrical Power Subsystem (EPS) experienced a fault that probably originated in the RWA-X electronics. The fault has cleared and the EPS is operating normally. The TWTA-2 filament of the Telecommunications subsystem switched OFF in response to the EPS fault, as designed. It is back on line and operating nominally. The Payload Data Subsystem (PDS) experienced a "warm" Power On Reset (POR) and the payload bus current momentarily dropped by 0.2 amps. The PDS RAM remained intact, allowing the PDS to recover within two telemetry frames. All other subsystems report nominal health.

Uplinks:

There have been 18 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, the background sequences, anomaly related commands, and the mz071 mini-sequence. There have been 5,091 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm109 background sequence will be uplinked on 01-026 (1/26/01). The Roll Only Targeted Observation (ROTO) demonstration scheduled for this weekend has been delayed pending results from the anomaly investigation. Another DDOR experiment is scheduled for 01-027 (1/27/01). It is contained in the mm108 sequence. 01-031 (1/31/01) will mark the end of the MGS primary mission and 01-032 (2/1/01) will mark our entry into the extended mission phase.


Wednesday, January 17, 2001 (DOY 010/19:00:00 to DOY 017/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1533 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 657 days
Total Mapping Orbits = 8,331
Total Orbits = 10,014

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm104 sequence executed successfully from 01-011 (1/11/00) through 01-013 (1/13/01). The mm105 sequence has performed well since it started on 01-014 (1/14/01). It terminates on 01-017 (1/17/01). The mm106 sequence, successfully uplinked on 01-016 (1/16/01), begins executing on 01-018 (1/18/01).

Other - MGS successfully completed twelve Radio Science Occultation Egress Scans from 01-010 (1/10/01) to 01-011 (01/11/01). One Delta Differential One-Way Range (DDOR) experiment was conducted on 01-013 (1/13/01). Data from this and other DDOR experiments are being analyzed and should assist the Mars Odyssey Program in calibrating the interplanetary navigation system.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 8 uplinks to the spacecraft during the last week, including instrument command loads, the background sequences cited above, and the mz070 mini-sequence. There have been 5,073 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm107 background sequence will be uplinked on 01-019 (1/19/01). MOLA Polar Scans, contained in the mz070 mini-sequence, are scheduled for 01-018 (1/18/01) through 01-022 (1/22/01). On 01-025 (1/25/01), a Roll Only Targeted Observation (ROTO) demonstration will be conducted on the spacecraft. It will verify our readiness to conduct these observations during the extended mission. Two more DDOR experiments are scheduled for 01-024 (1/24/01) and 01-027 (1/27/01). 01-031 (1/31/01) will mark the end of the MGS primary mission and 01-032 (2/1/01) will mark our entry into the extended mission.


Wednesday, January 10, 2001 (DOY 003/19:00:00 to DOY 010/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1526 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 650 days
Total Mapping Orbits = 8,245
Total Orbits = 9,848

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm102 sequence executed successfully from 01-004 (1/4/00) through 01-006 (1/6/01). The mm103 sequence has performed well since it started on 01-007 (1/7/01). It terminates on 01-010 (1/10/01). The mm104 sequence, successfully uplinked on 01-009 (1/9/01), begins executing on 01-011 (1/11/01).

Other -- Two Delta Differential One-Way Range (DDOR) experiments were conducted on 01-009 (1/9/01). Data from these DDOR experiments are being analyzed and should assist the Mars Odyssey Program in calibrating the interplanetary navigation system.

Spacecraft Health:

All subsystems report nominal health.

Uplinks: There have been 16 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and the mz068 and mz069 mini-sequences. There have been 5,065 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm105 background sequence will be uplinked on 01-012 (1/12/01). Radio Science Occultation Egress Scans, scheduled for 01-010 (1/10/01) through 01-011 (01/11/01), will be commanded by the,mz068, & mz069 mini-sequences. Another DDOR experiment will be conducted on 01-013 (1/13/01). MOLA Polar Scans are scheduled for 01-018 (1/18/01) through 01-022 (1/22/01). On 01-025 (1/25/01), a Roll Only Targeted Observation (ROTO) demonstration will be conducted on the spacecraft. It will verify our readiness to conduct these observations during the extended mission. Two more DDOR experiments are scheduled for 01-024 (1/24/01) and 01-027 (1/27/01). 01-031 (1/31/01) will mark the end of the MGS primary mission and 01-032 (2/1/01) will mark our entry into the extended mission.


Wednesday, December 20, 2000 (DOY 348/19:00:00 to DOY 355/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1505 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 629 days
Total Mapping Orbits = 7,988
Total Orbits = 9,591

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm096 sequence executed successfully from 00-349 (12/14/00) through 00-351 (12/16/00). The mm097 sequence has performed well since it started on 00-352 (12/17/00). It terminates on 00-355 (12/20/00). The mm098 sequence, successfully uplinked on 00-354 (12/19/00), begins executing on 00-356 (12/21/00).

Other -- Science Campaign F, which started on 00-345 (12/10/00), finishes tomorrow 00-356 (12/21/00). MGS received 24 hour/day coverage during the campaign, greatly increasing the amount of high resolution real-time science data that it transmitted to Earth. The first of two back-to-back Radio Science Occultation Egress Scan experiments was successfully completed yesterday 00-354 (12/19/00). The second experiment started today and terminates tomorrow 00-356 (12/21/00).

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 19 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. There have been 5,026 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm099, mm100, mm101, and mm102 background sequences will be uplinked on 00-357 (12/22/00), 00-361 (12/26/00), 00-364 (12/29/00), and 01-002 (01/02/01) respectively. Two Delta Differential One-Way Range (DDOR) experiments will be conducted on 01-009 (1/9/01). Data from these DDOR experiments will assist the Mars Odyssey Program in calibrating the interplanetary navigation system. Radio Science Occultation Egress Scans, scheduled for 01-010 (1/10/01) through 01-011 (01/11/01), will be commanded by the,mz068, & mz069 mini-sequences.


Wednesday, December 13, 2000 (DOY 341/19:00:00 to DOY 348/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1498 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 622 days
Total Mapping Orbits = 7,902
Total Orbits = 9,505

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm094 sequence executed successfully from 00-342 (12/7/00) through 00-344 (12/9/00). The mm095 sequence has performed well since it started on 00-345 (12/10/00). It terminates on 00-348 (12/13/00). The mm096 sequence, successfully uplinked on 00-347 (12/12/00), begins executing on 00-349 (12/14/00).

Other - No special science scans were conducted this week. Science Campaign F started on 00-345 (12/10/00) and lasts until 00-356 (12/21/00). MGS is receiving 24 hour/day coverage during the campaign, greatly increasing the amount of high resolution real-time science data that it transmits to Earth.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 7 uplinks to the spacecraft during the last week, including instrument command loads and the sequences cited above. There have been 5,007 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm097 background sequence will be uplinked on 00-350 (12/15/00). Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00) through 00-356 (12/21/00), will be commanded by the mz065,mz066, & mz067 mini-sequences.


Wednesday, December 6, 2000 (DOY 334/19:00:00 to DOY 341/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1491 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 615 days
Total Mapping Orbits = 7,817
Total Orbits = 9,420

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm092 sequence executed successfully from 00-335 (11/30/00) through 00-337 (12/2/00). The mm093 sequence has performed well since it started on 00-338 (11/3/00). It terminates on 00-341 (11/6/00). The mm094 sequence, successfully uplinked on 00-340 (12/5/00), begins executing on 00-342 (12/7/00).

Other - No special science scans were conducted this week.

Spacecraft Health:

All subsystems report nominal health.

Uplinks: There have been 8 uplinks to the spacecraft during the last week, including instrument command loads and the sequences cited above. There have been 5,000 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm095 background sequence will be uplinked on 00-343 (12/8/00). Science Campaign F commences on 00-345 (12/10/00) and lasts until 00-356 (12/21/00). Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00) through 00-356 (12/21/00), will be commanded by the mz065,mz066, & mz067 mini-sequences.


Wednesday, November 29, 2000 (DOY 327/19:00:00 to DOY 334/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1484 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 608 days
Total Mapping Orbits = 7,731
Total Orbits = 9,334

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm090 sequence executed successfully from 00-328 (11/23/00) through 00-330 (11/25/00). The mm091 sequence has performed well since it started on 00-331 (11/26/00). It terminates on 00-334 (11/29/00). The mm092 sequence, successfully uplinked on 00-333 (11/28/00), begins executing on 00-335 (11/30/00).

The background sequences now command SSR record and playback rates of 8 ksps and 42 ksps respectively. We were able to double the previous rates because of the improved telecom link margin available, as Earth and Mars get closer to each other. The change took effect on 00-331 (11/26/00).

Other - No special science scans were conducted this week.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. There have been 4,992 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm093 background sequence will be uplinked on 00-336 (12/1/00). Science Campaign F commences on 00-345 (12/10/00) and lasts until 00-356 (12/21/00). Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00) through 00-356 (12/21/00), will be commanded by the mz065,mz066, & mz067 mini-sequences.


Wednesday, November 22, 2000 (DOY 320/19:00:00 to DOY 327/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1477 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 601 days
Total Mapping Orbits = 7,645
Total Orbits = 9,248

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm088 sequence executed successfully from 00-321 (11/16/00) through 00-323 (11/18/00). The mm089 sequence has performed well since it started on 00-324 (11/20/00). It terminates on 00-327 (11/22/00). The mm090 sequence, successfully uplinked on 00-326 (11/21/00), begins executing on 00-328 (11/23/00).

Other - Radio Science Occultation Egress Scans, contained in the mz063 and mz064 mini-sequences, were accomplished successfully on 00-322 (11/17/00) through 00-325 (11/20/00). Twenty-four total scans were performed.

Spacecraft Health:

All subsystems report nominal health. Telecom link margin is improving as the distance between Earth and Mars decreases. This will allow us to increase the record and playback rates by a factor of two. We plan to increase the record rate to 8 ksps on 00-331 (11/26/00) and the playback rate to 42 ksps on 00-332 (11/27/00).

Uplinks:

There have been 17 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. There have been 4,979 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm091 background sequence will be uplinked on 00-329 (11/24/00). Science Campaign F commences on 00-345 (12/10/00) and lasts until 00-356 (12/21/00). Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00) through 00-356 (12/21/00), will be commanded by the mz065 & mz066 mini-sequences.


Wednesday, November 15, 2000 (DOY 313/19:00:00 to DOY 320/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1470 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 594 days
Total Mapping Orbits = 7,559
Total Orbits = 9,162

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm086 sequence executed successfully from 00-314 (11/9/00) through 00-316 (11/11/00). The mm087 sequence has performed well since it started on 00-317 (11/13/00). It terminates on 00-320 (11/15/00). The mm088 sequence, successfully uplinked on 00-319 (11/14/00), begins executing on 00-321 (11/16/00).

Other - MOLA Polar Scans, contained in the mz062 mini-sequence, were performed successfully on 00-316 (11/11/00) through 00-319 (11/14/00). Data processing will begin as soon as the data are available on the central database.

Spacecraft Health:

All subsystems report nominal health. Telecom link margin is improving as the distance between Earth and Mars decreases. This will allow us to increase the record and playback rates by a factor of two. We plan to increase the record rate to 8 ksps on 00-331 (11/26/00) and the playback rate to 42 ksps on 00-332 (11/27/00).

Uplinks:

There have been 15 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. Unfortunately, seven uplinks attempted today (00-320) were unsuccessful due to bad spacecraft frequency predictions. The affected command files will be uplinked tomorrow morning, 00-321 (11/16/00). There have been 4,947 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm089 background sequence will be uplinked on 00-322 (11/17/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz063 & mz064 mini-sequences. The mz063a command file will be retransmitted to the spacecraft tomorrow, 00-321 (11/16/00), because today's attempt failed as explained above.


Wednesday, November 8, 2000 (DOY 306/19:00:00 to DOY 313/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1463 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 587 days
Total Mapping Orbits = 7,473
Total Orbits = 9,076

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm084 sequence executed successfully from 00-307 (11/2/00) through 00-309 (11/4/00). The mm085 sequence has performed well since it started on 00-310 (11/6/00). It terminates on 00-313 (11/8/00). The mm086 sequence, successfully uplinked on 00-312 (11/7/00), begins executing on 00-314 (11/9/00).

Other - No special science scans were conducted this week.

Spacecraft Health:

All subsystems report nominal health. The Safe Mode mission-phase-relays have been commanded to the Mapping state. Therefore, in the unlikely event that MGS enters Safe Mode, it will remain in a positive power margin state.

Uplinks:

There have been 8 uplinks to the spacecraft during the last week, including instrument command loads, the sequences cited above, and the command to change the mission-phase-relays to Mapping. There have been 4,947 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm087 background sequence will be uplinked on 00-315 (11/10/00). MOLA Polar Scans, contained in the mz062 mini-sequence, will be performed on 00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz063 & mz064 mini-sequences.


Wednesday, October 25, 2000 (DOY 292/19:00:00 to DOY 299/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1449 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 573 days
Total Mapping Orbits = 7,303
Total Orbits = 8,906

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm080 sequence executed successfully from 00-293 (10/19/00) through 00-295 (10/21/00). The mm081 sequence has performed well since it started on 00-296 (10/22/00). It terminates on 00-299 (10/25/00). The mm080 sequence, successfully uplinked on 00-298 (10/24/00), begins executing on 00-300 (10/26/00).

Other - No special science scans were conducted this week.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 7 uplinks to the spacecraft during the last week, including instrument command loads and the sequences cited above. There have been 4,924 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm083 background sequence will be uplinked on 00-301 (10/27/00). The next set of specialized science observations occur in November. MOLA Polar Scans, contained in the mz062 mini-sequence, will be performed on 00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz063 mini-sequence.


Wednesday, October 18, 2000 (DOY 285/19:00:00 to DOY 292/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1442 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 566 days
Total Mapping Orbits = 7,217
Total Orbits = 8,820

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm078 sequence executed successfully from 00-286 (10/12/00) through 00-288 (10/14/00). The mm079 sequence has performed well since it started on 00-289 (10/15/00). It terminates on 00-292 (10/18/00). The mm080 sequence, successfully uplinked on 00-291 (10/17/00), begins executing on 00-293 (10/19/00).

Other - MGS successfully completed twelve Radio Science Occultation Egress Scans on 00-287 (10/13/00) and 00-288 (10/14/00). They were part of the mz061 mini-sequence.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads and the sequences cited above. There have been 4,917 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm081 background sequence will be uplinked on 00-294 (10/20/00). The next set of specialized science observations occur in November. MOLA Polar Scans, contained in the mz062 mini-sequence, will be performed on 00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz062 mini-sequence.


Wednesday, October 11, 2000 (DOY 278/19:00:00 to DOY 285/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1435 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 559 days
Total Mapping Orbits = 7,131
Total Orbits = 8,734

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm076 sequence executed successfully from 00-279 (10/5/00) through 00-281 (10/7/00). The mm077 sequence has performed well since it started on 00-282 (10/8/00). It terminates on 00-285 (10/11/00). The mm078 sequence, successfully uplinked on 00-285 (10/11/00), begins executing on 00-286 (10/12/00).

Other - MGS completed fifteen MOLA Polar Scans over five days from 00-281 (10/7/00) through 00-285 (10/11/00). They were part of the mz059 mini-sequence.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads and the sequences cited above. There have been 4,904 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm079 background sequence will be uplinked on 00-287 (10/13/00). The next set of specialized science observations occur in November. MOLA Polar Scans, contained in the mz062 mini-sequence, will be performed on 00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz062 mini-sequence.


Wednesday, October 4, 2000 (DOY 271/19:00:00 to DOY 278/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1428 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 552 days
Total Mapping Orbits = 7,045
Total Orbits = 8,648

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm074 sequence executed successfully from 00-272 (9/28/00) through 00-274 (9/30/00). The mm075 sequence has performed well since it started on 00-275 (10/1/00). It terminates on 00-278 (10/4/00). The mm076 sequence, successfully uplinked on 00-277 (10/3/00), begins executing on 00-279 (10/5/00).

Other - This week MGS completed the fifth and sixth MOC Focus Calibrations. Both MOC Calibration Images hit the three targeted stars (Alcyone, Maia and Taygeta) with no image drops near the stars. Cross-track positions measured 2.1 - 2.2 milli-radians from the center on the same side of the detector as observed in previous star images. This is within the MGS pointing accuracy error budget.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 16 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads and the sequences cited above. There have been 4,891 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm077 background sequence will be uplinked on 00-280 (10/6/00). MOLA Polar Scans, contained in the mz059 mini-sequence, will be performed on 00-281 (10/7/00) through 00-285 (10/11/00). Radio Science Occultation Egress Scans, scheduled for 00-287 (10/13/00) and 00-288 (10/14/00), will be commanded by the mz061 mini-sequence.


Wednesday, September 27, 2000 (DOY 264/19:00:00 to DOY 271/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1421 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 545 days
Total Mapping Orbits = 6,959
Total Orbits = 8,562

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm072 sequence executed successfully from 00-265 (9/21/00) through 00-267 (9/23/00). The mm073 sequence has performed well since it started on 00-268 (9/24/00). It terminates on 00-271 (9/27/00). The mm074 sequence, successfully uplinked on 00-270 (9/26/00), begins executing on 00-272 (9/28/00).

Other - This week MGS completed the second, third, and forth of five scheduled MOC Focus Calibrations. The results of calibration #2 were inconclusive due to gaps in the data. The Deep Space Network antenna had difficulty maintaining the data downlink due to poor weather at the receiver site. MOC Focus Calibrations #3 and #4 were successful in imaging most of the targeted stars, providing scientists and engineers with data that will be used to improve the precision MOC targeting capabilities of MGS.

Spacecraft Health:

All subsystems report nominal health. During the beta-supplement phase of this mission we have been contending with the issue of how to retrieve from MGS all of the science and engineering data that is recorded. We knew that eventually planetary position geometry combined with the need to maneuver the spacecraft around the HGA gimbal obstruction would result in our inability to playback all of the data within the available downlink windows. We have attempted two modifications in the Solid State Recorder (SSR) record/playback strategy over the past weeks. The modification that works the best is analogous to pressing the "pause" button on a typical tape recorder. So, every time we playback SSR Track 7, we command the SSR to "pause" just before MGS becomes occulted by Mars or it maneuvers around the HGA gimbal obstruction. We pick up the playback of SSR Track 7 during the next downlink opportunity. Presently, it takes three separate downlink opportunities to playback SSR Track 7 completely. With less than 45 minutes of each 2 hour orbit available for playback, it already takes 12 downlink opportunities over 6 complete orbits to playback SSR Tracks 1 through 6. Therefore, MGS requires 15 - 16 hours of downlink each day to playback all recorded data. This situation will gradually improve as planetary geometry becomes more favorable. The beta-supplement phase of this mission ends in late June of 2001.

Uplinks:

There have been 13 uplinks to the spacecraft during the last week, including instrument command loads and sequences cited above. There have been 4,875 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm075 background sequence will be uplinked 00-273 (9/29/00). MOC Focus Calibration #5 contained in the mz058 mini-sequence, will be performed on 00-272 (9/28/00). An additional MOC Focus Calibration (#6) is scheduled for 00-277 (10/3/00) to gain the data lost during MOC Focus Calibration #2. It's uplink designation will be mz060. MOLA Polar Scans, contained in the mz059 mini-sequence, will be performed 00-281 (10/7/00) through 00-285 (10/11/00). Radio Science Occultation Egress Scans are scheduled for 00-287 (10/13/00) and 00-288 (10/14/00).


Wednesday, September 20, 2000 (DOY 257/19:00:00 to DOY 264/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1414 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 538 days
Total Mapping Orbits = 6,874
Total Orbits = 8,477

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm070 sequence executed successfully from 00-258 (9/14/00) through 00-260 (9/16/00). The mm071 sequence has performed well since it started on 00-261 (9/17/00). It terminates on 00-264 (9/20/00). The mm072 sequence, successfully uplinked on 00-263 (9/19/00), begins executing on 00-265 (9/21/00).

Other - MGS successfully completed the first of five MOC Focus Calibrations on 00-262 (9/18/00). The MOC focus calibration image contained the three targeted stars (Alcyone, Maia and Taygeta). Downtrack position was good and crosstrack position improved from previous calibrations.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 17 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4,862 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm073 background sequence will be uplinked 00-266 (9/22/00). MOC Focus Calibrations #2 - #5, contained in the mz057 and mz058 mini-sequences, will be performed 00-266 (9/22/00) through 00-272 (9/28/00). MOLA Polar Scans will be performed 00-281 (10/7/00) through 00-285 (10/11/00). They will be contained in the mz059 mini-sequence.


Wednesday, September 13, 2000 (DOY 250/19:00:00 to DOY 257/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1407 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 531 days
Total Mapping Orbits = 6,788
Total Orbits = 8,391

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm068 sequence executed successfully from 00-251 (9/7/00) through 00-253 (9/09/00). The mm069 sequence has performed well since it started on 00-254 (9/10/00). It terminates on 00-257 (9/13/00). The mm070 sequence, successfully uplinked on 00-256 (9/12/00), begins executing on 00-258 (9/14/00).

Other - MGS successfully completed twelve Radio Science Occultation Egress Scans, between 00-252 (9/8/00) and 00-253 (9/09/00). They were contained in the mz055 mini-sequence. Scientists are analyzing the resulting data set.

Spacecraft Health:

All subsystems report nominal health. Because MGS is approaching aphelion, the average energy margin per orbit has been dropping as expected. Two new solar array motion scripts, designed to increase power margin, began operating on 00-251 (9/7/00). The spacecraft is now maintaining 60 Watt-hours of average energy margin per orbit compared to 35 Watt-hours just before the new scripts took effect. We expect the spacecraft to maintain an average energy margin per orbit greater than 40 Watt-hours through aphelion.

Uplinks:

There have been 15 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4,845 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm071 background sequence will be uplinked 00-259 (9/15/00). MOC Focus Calibrations, scheduled for 00-262 (9/18/00) through 00-272 (9/28/00), will be contained in the mz056, mz057, and mz058 mini-sequences.


Wednesday, September 06, 2000 (DOY 243/19:00:00 to DOY 250/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1400 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 524 days
Total Mapping Orbits = 6,703
Total Orbits = 8,306

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm066 sequence executed successfully from 00-244 (8/31/00) through 00-246 (9/02/00). The mm067 sequence has performed well since it started on 00-247 (9/3/00). It terminates on 00-250 (9/6/00). The mm068 sequence, successfully uplinked on 00-249 (8/5/00), begins executing on 00-251 (9/7/00).

Other - Between 00-243 (8/30/00) and 00-246 (9/2/00) MGS specifically targeted the North and South poles with the laser altimeter during thirteen orbits covering 360 degrees of latitude. Now that the mz054 MOLA Polar Scan mini-sequence has successfully terminated, scientists are processing the resulting data set.

Spacecraft Health:

All subsystems report nominal health. As MGS approaches aphelion, the average energy margin per orbit is dropping as expected. Two new solar array motion scripts have been uplinked to maintain 40 Watt-hours of average energy margin per orbit while MGS travels near aphelion. They take effect on 00-251 (9/7/00).

Uplinks:

There have been 17 uplinks to the spacecraft during the last week, including instrument command loads, the previously cited background sequences, the two new solar array motion scripts, and the mz055 mini-sequence. The mz055 mini-sequence will command Radio Science Occultation Egress Scans between 00-252 (9/8/00) and 00-253 (9/09/00).

There have been 4,830 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm069 background sequence will be uplinked 00-252 (9/8/00). MOC Focus Calibrations, scheduled for 00-262 (9/18/00) through 00-272 (9/28/00), will be contained in the mz056, mz057, and mz058 mini-sequences.


Wednesday, August 30, 2000 (DOY 236/19:00:00 to DOY 243/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1393 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 517 days
Total Mapping Orbits = 6,617
Total Orbits = 8,220

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm064 sequence executed successfully from 00-237 (8/24/00) through 00-239 (8/26/00). The mm065 sequence has performed well since it started on 00-240 (8/27/00). It terminates on 00-243 (8/30/00). The mm066 sequence, successfully uplinked on 00-242 (8/29/00), begins executing on 00-244 (8/31/00).

Other - The mz054 mini-sequence containing the MOLA Polar Scans was uplinked 00-241 (8/28/00). Between 00-243 (8/30/00) and 00-246 (9/2/00) MGS will specifically target the North and South poles with the laser altimeter during thirteen orbits covering 360 degrees of latitude.

Spacecraft Health:

All subsystems report nominal health. As MGS approaches aphelion, the average energy margin per orbit is dropping as expected. Power projections indicate that the average energy margin per orbit will drop below the 40 Watt-hour threshold between early September 2000 and mid-January 2001. Though the spacecraft is capable of operating nominally below this threshold, the project has elected to maintain the average energy margin at or above 40 Watt-hours. The on-board command scripts that control solar array motion will be modified to provide the desired margin. This change will take effect 00-251 (9/7/00).

Uplinks:

There have been 9 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4,813 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm067 background sequence will be uplinked 00-245 (9/1/00). Radio Science Occultation Egress Scans, scheduled for 00-252 (9/8/00) through 00-253 (9/09/00), are contained in the mz055 mini-sequence. It will be uplinked 00-250 (9/6/00). MOC Focus Calibrations are scheduled for 00-262 (9/18/00) through 00-272 (9/28/00).


Wednesday, August 16, 2000 (DOY 222/19:00:00 to DOY 229/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1379 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 503 days
Total Mapping Orbits = 6446
Total Orbits = 8049

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm060 sequence executed successfully from 00-223 (8/10/00) through 00-225 (8/12/00). The mm061 sequence has performed well since it started on 00-226 (8/13/00). It terminates on 00-229 (8/16/00). The mm062 sequence, successfully uplinked on 00-228 (8/15/00), begins executing on 00-230 (8/17/00).

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 14 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4788 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm063 background sequence will be uplinked 00-231 (8/18/00). MOLA Polar Scans are scheduled for 00-243 (8/30/00) through 00-246 (9/2/00).


Wednesday, August 9, 2000 (DOY 215/19:00:00 to DOY 222/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1372 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 496 days
Total Mapping Orbits = 6360
Total Orbits = 7963

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm058 sequence executed successfully from 00-216 (8/03/00) through 00-218 (8/05/00). The mm059 sequence has performed well since it started on 00-219 (8/06/00). It terminates on 00-222 (8/09/00). The mm060 sequence, successfully uplinked on 00-222 (8/09/00), begins executing on 00-223 (8/10/00).

The spacecraft successfully completed twelve Radio Science Occultation Egress Scans on 00-221 (8/8/00) and 00-222 (8/9/00). The AACS performed well using the same off-NADIR pointing scheme that proved successful last May.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 9 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4774 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm061 background sequence will be uplinked 00-224 (8/11/00). MOLA Polar Scans are scheduled for 00-242 (8/29/00) through 00-246 (9/2/00).


Wednesday, August 2, 2000 (DOY 208/19:00:00 to DOY 215/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1365 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 489 days
Total Mapping Orbits = 6274
Total Orbits = 7877

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm056 sequence executed successfully from 00-209 (7/27/00) through 00-211 (7/29/00). The mm057 sequence has performed well since it started on 00-212 (7/30/00). It terminates on 00-215 (8/02/00). The mm058 sequence, successfully uplinked on 00-214 (8/01/00), begins executing on 00-216 (8/03/00).

On 00-214 (8/01/00), the MOLA was turned on as part of the mm057 sequence. It had been off for a two-month period that included Solar Conjunction. MOLA laser transmitter life is directly related to its on-time. We plan to double its remaining useful life by operating the instrument every other month.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4765 command files radiated to the spacecraft since launch.

Upcoming Events:

The mz053 mini-sequence will be uplinked 00-216 (8/03/00). It contains the Radio Science Occultation Egress Scans that will take place on 00-221 (8/8/00) and 00-222 (8/9/00). The mm059 background sequence will be uplinked 00-217 (8/04/00).


Wednesday, July 26, 2000 (DOY 201/19:00:00 to DOY 208/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1358 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 482 days
Total Mapping Orbits = 6189
Total Orbits = 7792

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm054 sequence executed successfully from 00-202 (7/20/00) through 00-204 (7/22/00). The mm055 sequence has performed well since it started on 00-205 (7/23/00). It terminates on 00-208 (7/26/00). The mm056 sequence, successfully uplinked on 00-207 (7/25/00), begins executing on 00-209 (7/27/00).

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. On 00-203 (7/21/00) we successfully demonstrated the capability to perform uplinks using the new DSS-14 X-band transmitter. There have been 4752 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm057 background sequence will be uplinked 00-210 (7/28/00). The MOLA will be turned-on on 00-214 (8/1/00). Radio Science Occultation Egress Scans will take place 00-221 (8/8/00) and 00-222 (8/9/00).


Wednesday, July 19, 2000 (DOY 194/19:00:00 to DOY 201/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1351 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 475 days
Total Mapping Orbits = 6103
Total Orbits = 7706

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm052 sequence executed successfully from 00-195 (7/13/00) through 00-197 (7/15/00). The mm053 sequence has performed well since it started on 00-198 (7/16/00). It terminates on 00-201 (7/19/00). The mm054 sequence, successfully uplinked on 00-200 (7/18/00), begins executing on 00-202 (7/20/00).

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 12 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, MOC turn-on commands, instrument command loads, and the background sequences cited above. There have been 4739 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm055 background sequence will be uplinked 00-203 (7/21/00).


Wednesday, July 12, 2000 (DOY 187/19:00:00 to DOY 194/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1344 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 468 days
Total Mapping Orbits = 6017
Total Orbits = 7620

Recent Events:

Background Sequences -- We are in the last day of the Solar Conjunction phase of the mission and sequences continue to execute nominally. The mm051 sequence will terminate and the mm052 sequence will begin on 00-195 (7/13/00). mm052, the first beta-supplement sequence to execute since 00-174 (6/22/00), will start recording science data on 00-195 (7/13/00). Playbacks of science data commence on 00-196 (7/14/00).

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 10 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files and the mm052 background sequence. We turned off two-way non-coherent mode to regain two-way Doppler capability and we set the Command Loss Timer to its nominal value of 104 hours. The total number of command files radiated to the spacecraft since launch is 4727.

Upcoming Events:

The MOC will be turned on tomorrow, 00-195 (7/13/00), via real-time commands. The mm053 background will be uplinked 00-196 (7/14/00).


Wednesday, July 05, 2000 (DOY 180/19:00:00 to DOY 187/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1337 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 461 days
Total Mapping Orbits = 5932
Total Orbits = 7535

Recent Events:

Background Sequences -- We are in the Solar Conjunction phase of the mission. The mm050 sequence is progressing nominally. The mm051 sequence will commence on 00-190, (7/8/00).

Spacecraft Health:

All subsystems report nominal health. We saw the noise in the downlink signal increase as the Sun-Earth-Mars (SEM) angle approached the minimum value of 0.87 degrees on 00-183 (7/1/00). We received no telemetry from 00-181 (6/29/00) through 00-183 (7/1/00) due to Solar Conjunction. Now, the downlink signal is gradually improving as the SEM angle increases.

Uplinks:

No commands were uplinked this week. Total command files radiated to the spacecraft since launch is 4717.

Upcoming Events:

We expect to return to normal spacecraft configuration and beta-supplement command sequences starting with the mm052 sequence on 00-195 (7/13/00). We continue to monitor spacecraft health and the actual vs. predicted timing of orbital events. The spacecraft attempts to contact Earth during three of the twelve orbits each day during the Solar Conjunction period. When the downlink signal is good, we receive engineering telemetry and the actual Mars equator crossing time for that orbit. We compare the actual equator crossing time with the predicted equator crossing time to determine the accuracy with which we placed spacecraft maneuvers. We expect the accuracy of our orbital timing to degrade with time. Tracking the rate at which the timing degrades helps us ensure the spacecraft health during the Solar Conjunction. We are prepared to cancel or rebuild stored sequences if timing degradation reaches unacceptable levels. Presently our predictions deviate from actual orbit timing by less than twenty-two seconds. This is well within the established timing envelope. Timing would have to deviate by 75 seconds before we considered canceling the stored sequence. We anticipate satisfactory timing throughout the remainder of mm050 and mm051. We expect to obtain satisfactory two-way Doppler tracking data on 00-190 (7/8/00). Orbital timing estimates will return to normal in the week following. Sequence development of mm052 and mm053 is proceeding nominally.


Wednesday, June 28, 2000 (DOY 173/19:00:00 to DOY 180/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1330 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 454 days
Total Mapping Orbits = 5846
Total Orbits = 7449

Recent Events:

Background Sequences -- The mm050 and mm051 Solar Conjunction sequences were uplinked successfully and the MOC was turned off by commands in the mm049 sequence. The mm050 sequence became active on 00-175 (6/23/00). We are now in the Solar Conjuction phase of the mission.

Spacecraft Health:

All subsystems report nominal health. We are seeing more noise in the downlink signal as the Sun-Earth-Mars angle decreases. This is expected. The Sun-Earth-Mars angle will reach a minimum of 0.87 degrees on 00-183 (7/1/00). The downlink signal will gradually improve with time beyond that date.

Uplinks:

Only one file was uplinked to the spacecraft during the last week. It was the mm051 sequence. Total command files radiated to the spacecraft since launch is 4717.

Upcoming Events:

We expect to return to normal spacecraft configuration and beta-supplement command sequences starting with the mm052 sequence on 00-195 (7/13/00). Until then, we will monitor spacecraft health and the actual vs. predicted timing of orbital events. The spacecraft attempts to contact Earth during three of the twelve orbits each day during the Solar Conjunction period. When the downlink signal is good, we receive engineering telemetry and the actual Mars equator crossing time for that orbit. We compare the actual equator crossing time with the predicted equator crossing time to determine the accuracy with which we placed spacecraft maneuvers. We expect the accuracy of our orbital timing to degrade with time. Tracking the rate at which the timing degrades will help us ensure the spacecraft health during the next few weeks. We are prepared to cancel or rebuild stored sequences if timing degradation reaches unacceptable levels. Presently our predictions deviate from actual orbit timing by less than six seconds. This is well within the established parameters (Gee, I sound like Data). Once the spacecraft emerges from Solar Conjunction and we are able to obtain two-way Doppler tracking data, our orbital timing estimates will return to normal.


Wednesday, June 14, 2000 (DOY 159/19:00:00 to DOY 166/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1316 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 440 days
Total Mapping Orbits = 5674
Total Orbits = 7277

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm046 background sequence executed successfully from 00-160 (6/08/00) through 00-163 (6/11/00). The mm047 background sequence has been performing nominally since 00-164 (6/12/00) and will terminate at the end of day 00-166 (6/14/00). The mm048 sequence was successfully uplinked on 00-165 (6/13/00) and will begin executing on 00-167 (6/15/00).

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 17 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. Total command files radiated to the spacecraft since launch is 4702.

Upcoming Events:

We are in the final stages of Solar Conjunction command sequence generation and testing. The mm050 and mm051 sequences will contain the lion's share of spacecraft commands for the Solar Conjunction period, 6/21/00 through 7/12/00. To prepare for Solar Conjunction, the MOC will be turned off using commands resident in the mm049 sequence. We expect to return to normal spacecraft configuration and beta-supplement command sequences starting with mm052 on 00-195 (7/13/00).


Wednesday, June 07, 2000 (DOY 145/19:00:00 to DOY 159/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1309 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 433 days
Total Mapping Orbits = 5589
Total Orbits = 7192

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The following background sequences executed successfully: mm042 from 00-146 (5/25/00) through 00-149 (5/28/00); mm043 from 00-150 (5/29/00) through 00-152 (5/31/00); mm044 from 00-153 (6/01/00) through 00-156 (6/04/00); and mm045 from 00-157 (6/05/00) through 00-159 (6/07/00). The mm046 sequence was successfully uplinked on 00-158 (6/06/00) and will begin executing on 00-160 (6/08/00).

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 19 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. Total command files radiated to the spacecraft since launch is 4685.

Upcoming Events:

Normal beta-supplement sequences are planned between now and Solar Conjunction. We are in the initial stages of Solar Conjunction command sequence generation and testing. The mm050, and mm051 sequences will contain the lion's share of spacecraft commands for the Solar Conjunction period, 6/21/00 through 7/12/00. There will be some spacecraft configuration commands related to Solar Conjunction contained in the mm049 and mm052 sequences.


Wednesday, May 24, 2000 (DOY 131/19:00:00 to DOY 145/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1295 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 419 days
Total Mapping Orbits = 5418
Total Orbits = 7021

Recent Events:

Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The following background sequences executed successfully: mm038 from 00-132 (5/11/00) through 00-135 (5/14/00); mm039 from 00-136 (5/15/00) through 00-138 (5/17/00); mm040 from 00-139 (5/18/00) through 00-142 (5/21/00); and mm041 from 00-143 (5/22/00) through 00-145 (5/24/00). The mm042 sequence was successfully uplinked on 00-144 (5/23/00) and will begin executing on 00-146 (5/25/00).

Science Experiments - Three science experiment campaigns took place during the past two weeks. They were Bistatic Radar, MOLA Off-NADIR Polar Scans, and Radio Science Occultation Egress Scans. Commands for the Bistatic Radar experiment were included in the mm038 sequence as part of DOY 135 activities. Commands for the MOLA Off-NADIR Polar Scans composed the mz051 mini-sequence. They executed over 11 consecutive orbits on DOY 138 and DOY 139. Finally, MGS performed Radio Science Occultation Egress Scans on DOY 141,142, and 143 according to the mz052 mini-sequence. Overall, spacecraft performance during all experiments was nominal. The following paragraphs provide additional information regarding AACS performance.

In the MOLA experiment, we used the same CSA offset quaternions as the previous two polar opportunities. The SARBES (Starex reset) command was eliminated from this sequence and replaced with a general memory load of high rate gyro bias estimates and a separate software command to load the high rate steady state gyro biases. We also retained the divided North and South Pole slews implemented with the last MOLA polar opportunity. We are happy to report that the Starex problems observed in previous MOLA polar experiments have disappeared. Starex performance was completely, totally, and utterly nominal. Slew performance was superb, as it was for the previous polar experiments.

For the first time during a Radio Science Occultation Egress experiment, we used an Off-NADIR pointing scheme. AACS performance proved nominal, comparing well with predicts. Again, Starex performed superbly, converging in 10 stars. We successfully used the same method of gyro bias loading in the Radio Science experiment that we used in the MOLA Polar Scan experiment. Preliminary results indicate that the science teams received useful data during these experiments. Therefore, we plan to use the same spacecraft pointing and sequence development techniques for future MOLA and Radio Science experiments.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 28 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. Total command files radiated to the spacecraft since launch is 4666.

Upcoming Events:

Normal beta-supplement sequences are planned between now and Solar Conjunction. We are in the final stages of Solar Conjunction planning. The mm050 sequence will cover the Solar Conjunction period between 6/21/00 and 7/12/00.


Wednesday, May 10, 2000 (DOY 124/19:00:00 to DOY 131/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1281 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 405 days
Total Mapping Orbits = 5250
Total Orbits = 6853

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm036 sequence executed successfully from 00-125 (5/4/00) through 00-128 (5/7/00). The mm037 sequence also successfully executed from 00-129 (5/8/00) through 00-131 (5/10/00). The mm038 sequence was successfully uplinked on 00-130 (5/9/00) and will begin execution on 00-132 (5/11/00).

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 16 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm037 and mm038 sequences. Total command files radiated to the spacecraft since launch is 4638.

Upcoming Events:

A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is in final development and will execute on May 14. The commands to perform this experiment have been incorporated into the mm039 sequence, which is scheduled to be uplinked on 00-134 (5/13/00)

The next monthly MOLA off-nadir polar scan mini-sequence (mz051) is also in final development and will execute over 12 consecutive orbits beginning on May 17.

The implementation of the first Radio Science occultation egress scans, replacing the previous fixed-HGA periods for obtaining occultation egress data, is also in development at this time and is scheduled for execution on 5/20-5/22/00.


Wednesday, May 3, 2000 (DOY 117/19:00:00 to DOY 124/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1274 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 398 days
Total Mapping Orbits = 5164
Total Orbits = 6767

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm034 sequence executed successfully from 00-118 (4/27/00) through 00-121 (4/30/00). The mm035 sequence also successfully executed from 00-122 (5/1/00) through 00-124 (5/3/00). The mm036 sequence was successfully uplinked on 00-123 (5/2/00) and will begin execution on 00-125 (5/4/00).

The mz050 mini-sequence, containing the retry of the two missed MOC focus star scans, successfully executed on 4/28 and 4/30. The updated quaternion for these scans correctly accounted for the bias error due to the IMU being commanded to high rate mode and resulted in the stars being correctly centered in the image.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 11 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm035 and mm036 sequences. Total command files radiated to the spacecraft since launch is 4622.

Upcoming Events:

A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is in final development and will execute on May 14.

The next monthly MOLA Off-Nadir Polar Scans is about to begin development. The scans are scheduled for 12 consecutive orbits beginning on May 17.

The implementation of the first Radio Science occultation egress scans, replacing the previous fixed-HGA periods for obtaining occultation egress data, is also on schedule for execution on 5/20-5/22/00.


Wednesday, April 26, 2000 (DOY 110/19:00:00 to DOY 117/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1267 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 391 days
Total Mapping Orbits = 5078
Total Orbits = 6681

Recent Events:

MGS reached the 5000 mapping orbit milestone on 00-111 (4/20/00) at 12:31:55 UTC.

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm032 sequence executed successfully from 00-111 (4/20/00) through 00-114 (4/23/00). The mm033 sequence also successfully executed from 00-115 (4/24/00) through 00-117 (4/26/00). The mm034 sequence was successfully uplinked on 00-116 (4/25/00) and will begin execution on 00-118 (4/27/00). The mz050 mini-sequence, containing the retry of the two missed MOC focus star scans on 4/28 and 4/30, is scheduled for uplink on 00-118 (4/27/00).

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 19 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm033 and mm034 sequences. Total command files radiated to the spacecraft since launch is 4611.

Upcoming Events:

A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is on schedule for execution on 5/14/00.

The implementation of the first Radio Science occultation egress scans, replacing the previous fixed-HGA periods for obtaining occultation egress data, is also on schedule for execution on 5/20-5/22/00.


Wednesday, April 19, 2000 (DOY 0103/19:00:00 to DOY 0110/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1260 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 384 days
Total Mapping Orbits = 4992
Total Orbits = 6595

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm030 sequence executed successfully from 00-104 (4/13/00) through 00-107 (4/16/00). The mm031 sequence also successfully executed from 00-108 (4/17/00) through 00-110 (4/19/00). The mm032 sequence was successfully uplinked on 00-108 (4/17/00) and will begin execution on 00-111 (4/20/00).

A retry of the two missed MOC focus star scans is scheduled for 4/28 and 4/30. The second attempts will utilize an updated scan attitude to account for the gyro bias error propagated when the IMU is switched from low rate to high rate mode for the slews.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 11 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm032 and mm033 sequences. Total command files radiated to the spacecraft since launch is 4592.

Upcoming Events:

A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is on schedule for execution on 5/14/00, upon Project approval expected next week.

The implementation of the first Radio Science occultation egress scans, replacing the previous fixed-HGA periods for obtaining occultation egress data, are also on schedule for execution on 5/20-5/22/00.


Wednesday, April 12, 2000 (DOY 096/19:00:00 to DOY 0103/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1253 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 377 days
Total Mapping Orbits = 4906
Total Orbits = 6509

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm028 sequence executed successfully from 00-97 (4/6/00) through 00-100 (4/9/00). The mm029 sequence also successfully executed from 00-101 (4/10/00) through 00-103 (4/12/00). The mm030 sequence was successfully uplinked on 00-102 (4/11/00) and will begin execution on 00-104 (4/13/00).

Included in the mm028 sequence, was the fifth and last star scan of the current MOC focus campaign, and a 24-hour period of MOLA off-nadir scans of the North and South Poles, on 00-99 through 00-100 (4/8-4/9/00). The spacecraft performance during the final MOC star scan was nominal, but the stars were not seen in the image. Thus two of the five scans resulted in not seeing the stars. All indications are that the missed stars were due to a knowledge error in designing the scans. A retry of the two missing star scans will be scheduled for later in April, with an updated scan attitude.

Spacecraft performance during the MOLA scans was also nominal, with a single STAREX (star processing code) anomaly occurring proceeding the first MOLA off-nadir orbit. A STAREX autonomous reset occurred shortly after the sequence commanded the IMU to high rate mode and issued an intentional bias reset prior to the first off-nadir slew. After the autonomous reset STAREX converged properly and performed nominally for the duration of the MOLA scans.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 16 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm030 and mm031 sequences. Total command files radiated to the spacecraft since launch is 4581.

Upcoming Events:

Planning for the replacement of the monthly fixed-HGA periods for the purpose of obtaining radio science atmospheric occultation egress data, prohibited in normal beta supplement operations due to HGA gimbal constraints, proceeds. The first Radio Science occultation egress scans are scheduled for 5/20-5/22/00. Work has been underway over the last month on determining the feasibility of performing a bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth. All design hurdles have been cleared and work is now underway to implement this experiment for a May 14 opportunity.


Wednesday, April 5, 2000 (DOY 089/19:00:00 to DOY 096/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1245 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 370 days
Total Mapping Orbits = 4820
Total Orbits = 6423

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm026 sequence executed successfully from 00-90(3/30/00) through 00-93 (4/3/00). The mm027 sequence also successfully executed from 00-94 (4/4/00) through 00-96 (4/6/00). The mm028 sequence was successfully uplinked on 00-95 (4/5/00) and will begin execution on 00-97 (4/8/00). Included in the mm028 sequence, is the fifth and last star scan of the current MOC focus campaign, and a 24-hour period of MOLA off-nadir scans of the North and South Poles, scheduled on 00-99 through 00-100 (4/8-4/9/00). The mm029 sequence is scheduled to be uplinked on 00-99 (4/8/00) and will execute from 00-101 (4/10/00) through 00-103 (4/12/00).

The mz049 mini-sequence, containing the first four MOC star scans, has begun execution. The first three scans have completed to date. The MOC successfully acquired the desired stars from the first scan, but the stars were on the edge of their image. The second scan resulted in the MOC not seeing the stars. On the third scan the stars were acquired but were again on the edge of the image. The spacecraft attitude control errors were very small during each of the scans, leading us to believe there is some kind of knowledge error in the design of the scans, resulting in the stars not being centered in the image. AACS is currently analyzing the data and working with JPL and the MOC team to determine the cause of this error. Depending on the success of the fourth and fifth scans, additional scans may be performed in the next couple of weeks to ensure the MOC focus objective.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 14 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm028 and mm029 sequences. Total command files radiated to the spacecraft since launch is 4565.

Upcoming Events:

Planning for the replacement of the monthly fixed-HGA periods for the purpose of obtaining radio science atmospheric occultation egress data, prohibited in normal beta supplement operations due to HGA gimbal constraints, proceeds. The first Radio Science occultation egress scans are scheduled for 5/20-5/22/00.


Wednesday, March 29, 2000 (DOY 082/19:00:00 to DOY 089/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1241 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 363 days
Total Mapping Orbits = 4734
Total Orbits = 6337

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm024 sequence executed successfully from 00-83(3/23/00) through 00-86 (3/26/00). The mm025 sequence also successfully executed from 00-87 (3/27/00) through 00-89 (3/29/00). The mm026 sequence was successfully uplinked on 00-88 (3/28/00) and will begin execution on 00-89 (3/29/00). The mm027 sequence is scheduled to be uplinked on 00-92 (4/1/00) and will execute from 00-94 (4/3/00) through 00-96 (4/5/00). The mz049 mini-sequence, containing four MOC star scans for the purpose of improving the camera focus, was also uplinked successfully on 00-89 (3/29/00). The first star scan will occur on 00-90 at 14:35:56 GMT on the spacecraft.

The mm028 and mm029 sequences are currently in development. A fifth and final MOC focus star scan will be included in the mm028 sequence. It is intended to repeat the MOC focus scans every six months. Also included in the mm028 sequence is the next MOLA North and South Pole off-nadir scans. The MOLA polar scans will begin at approximately 12:00 GMT on 00-99 (4/8/00). The scans will take place over 12 consecutive orbits to provide complete longitudinal coverage of the poles.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 18 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm026, mm027 and mz049 sequences. Total command files radiated to the spacecraft since launch is 4551.

Upcoming Events:

Planning for the replacement of the monthly fixed-HGA periods for the purpose of obtaining radio science atmospheric occultation egress data, prohibited in normal beta supplement operations due to HGA gimbal constraints, proceeds.


Wednesday, March 22, 2000 (DOY 075/19:00:00 to DOY 082/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1234 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 356 days
Total Mapping Orbits = 4648
Total Orbits = 6251

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm022 sequence executed successfully from 00-75 (3/15/00) through 00-78 (3/18/00). The mm023 sequence also successfully executed from 00-79 (3/19/00) through 00-81 (3/21/00). The mm024 sequence was successfully uplinked on 00-81 (3/21/00) and began execution nominally on 00-82 (3/22/00). The mm025 sequence is scheduled to be uplinked on 00-85 (3/25/00) and will execute from 00-86 (3/26/00) through 00-88 (3/28/00).

Work has begun on the development of a series of MOC star scans to optimize the camera focus. Five total star scans of the Pleiades star cluster will be performed, one scan every other day, with the scan being done on the night-side of the orbit. The scans are currently scheduled on the days of 3/30, 4/01, 4/04, 4/05 and 4/07.

A series of FSW memory readout commands were performed over the last week and a half in order to determine the cause of an increased number of floating point overflow counts since the start of beta supplement operations. The results of the MROs determined that the overflows were coming from the polynomial evaluation function called by the articulation code and were a result of the HGA gimbals passing through 0 and 90 degrees, which is happening frequently during beta supplement due to the HGA management. The overflows appear to be benign and at this time, the SCT is still ascertaining whether any action is required.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 18 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm023 and mm024 sequences. Total command files radiated to the spacecraft since launch is 4533.

Upcoming Events:

MOLA Off-nadir North and South Pole scans scheduled for 4/8 and 4/9


Wednesday, March 15, 2000 (DOY 068/19:00:00 to DOY 075/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1227 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 349 days
Total Mapping Orbits = 4562
Total Orbits = 6165

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm020 sequence executed successfully from 00-63 (3/3/00) through 00-72 (3/12/00). The mm021 sequence also successfully executed from 00-63 (3/13/00) through 00-74 (3/14/00). The mm022 sequence was successfully uplinked on 00-73 (3/13/00) and began execution nominally on 00-74 (3/14/00).

Upon completion of the recent four day fixed-HGA mapping campaign performed last week, which resulted in higher than expected MOLA temperatures, the spacecraft team began looking at ways to fix the temperature problem. Additionally in assessing the first fixed-HGA campaign, it was noted that the actual transitions into and out of fixed-HGA mode of operations from the beta supplement mode of operations, were more complicated than anticipated and resulted in a larger than expected loss of science data from the other instruments. The Spacecraft Team presented at the 3/14 Project Mission Planning meeting alternatives to and options for fixing the current fixed-HGA operations. Fixed-HGA operations were to be performed 4-8 days per month for the express purpose of acquiring Radio Science Earth occultation egress measurements, which are prohibited during normal beta supplement mapping operations due to HGA gimbal constraints. From the Mission Planning meeting the favored option was to eliminate the fixed-HGA operations and perform special slews for a specified number of orbits to provide the desired longitudinal planetary coverage for the radio science occultation egress data, similar to the implementation of the MOLA off-nadir polar observations. Final details are in work and will be presented to the Project Change Board next Tuesday (3/21)

Spacecraft Health:

All subsystems are reporting nominal health. Battery 2 was successfully commanded back to VT-2 after transitioning back to beta supplement operations. The red alarm high limit for the MOLA temperature has been decreased by 3 degrees (from 35°C to 32°C) after a meeting with the MOLA engineers.

Uplinks:

There have been 20 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm021 and mm022 sequences. Two uplinks were missed after the final transition from the fixed-HGA Earth pointed attitude back to nadir pointed beta supplement operations due to a large change in the transponder temperature. The uplink sweeps for the beta supplement orbits are tailored specially for the very short uplink windows and are very sensitive to changes in the MOT temperature. The missing uplinks were successfully re-radiated. Total command files radiated to the spacecraft since launch is 4515.

Upcoming Events:

Planning has begun for a focus calibration of the MOC to be performed in late March.


Wednesday, March 8, 2000 (DOY 061/19:00:00 to DOY 068/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1220 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 342 days
Total Mapping Orbits = 4476
Total Orbits = 6158

Recent Events:

The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm018 sequence executed successfully from 00-62 (3/2/00) through 00-65 (3/5/00).

The mm019 sequence (i.e. first fixed-HGA sequence) began execution on 00-65 (3/5/00) and will run through completion of 00-68 (3/8/00). The mm019 sequence contains 12 orbits of MOLA off-nadir polar scans followed by three consecutive days of eight hour fixed-HGA Earth pointed periods, designed to allow radio science Earth occultation egress data, which is prohibited during beta supplement operations due to HGA boom and EMI interference constraints. Two incidents have occurred on the spacecraft during the execution of this sequence, as described below. The next sequence mm020 (another beta supplement sequence), scheduled to execute from 00-69 (3/9/00) through 00-72 (3/12/00), has been successfully uplinked to the spacecraft.

The first incident of the mm019 sequence was with star processing during the MOLA off-nadir Polar scans. The first 12 orbits of the mm019 sequence flew with a -17.1° nadir off-point angle for 45 minutes centered about the South Pole and a 14.4° nadir off-point angle for 45 minutes centered about the North Pole. This left about 30 minutes of star processing time per two-hour orbit. Anticipating that the limited star processing might be problematic, based on the previous MOLA polar scans performed last year, two things were done to ensure that the spacecraft would not lose inertial reference and enter contingency mode fault protection. First a commanded bias reset was issued two hours before the first MOLA scan to coincide with the IMU swap to high rate mode and second the lost logic limit, the number of unidentified stars allowed before an autonomous bias reset, was raised to 60 stars. Twice during the 12 orbit scan sequence, the lost logic limit was exceeded and an autonomous reset was commanded. After each reset the spacecraft successfully converged attitude. Three consecutive cumulative resets are required to actually cause entry into contingency mode. Prior to slewing the spacecraft to the first fixed-HGA Earth pointed attitude following the MOLA scans, the spacecraft attitude was nominal and star processing was properly converged. In spite of the star processing problems, the spacecraft successfully executed all of the slews and returned the data back to Earth, during the subsequent eight hour fixed-HGA Earth pointed period.

The second incident occurred when the MOLA laser temperature approached the 35° upper flight allowable limit, during the last orbit of the second eight-hour fixed-HGA Earth pointed period. The increased temperature was expected but the actual temperatures were about four degrees higher than that predicted by the thermal model. Real-time telemetry was not available for the flight team during the Earth pointed period, which is used for playback of the recorded data. The greater than expected temperature increase was noticed in the playback data on the third and last fixed-HGA Earth pointed period.

The Spacecraft Team is currently reassessing the monthly MOLA off-nadir polar orbit scans and the fixed-HGA Earth periods for radio science egress data, to determine what changes are required to ensure the safety of all the instruments and robustness of the spacecraft in performing these special events. Options will be presented to the Project at the 3/14 Mission Planning meeting. The next fixed-HGA sequence is scheduled for 00-076 (3/16/00) and will most likely be replaced with a beta supplement sequence.

Spacecraft Health:

All subsystems are reporting nominal health. As expected the battery DOD was greater during the four fixed-HGA Earth pointed orbits due to the additional transmitter on time associated with performing the radio science occultation egress event. As a result battery 2 autonomously switched to the VT 1 curve. Upon completion of the fixed-HGA sequence, battery 2 will be commanded back to VT 2.

Uplinks:

There have been 15 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm020 sequence. Total command files radiated to the spacecraft since launch is 4495.

Upcoming Events:

Planning has begun for a focus calibration of the MOC to be performed in late March.


Wednesday, March 1, 2000 (DOY 054/19:00:00 to DOY 061/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1213 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 335 days
Total Mapping Orbits = 4390
Total Orbits = 6072

Recent Events:

The spacecraft continues to operate nominally in performing the daily recording and transmission of the science data. The mm016 sequence executed successfully from 00-55 (2/24/00) through 00-58 (2/27/00). The mm017 sequence began execution on 00-59 (2/28/00) and will run through completion of 00-61 (3/1/00). The next sequence mm018, scheduled to execute from 00-62 (3/2/00) through 00-64 (3/4/00), has been successfully uplinked to the spacecraft.

The first fixed-HGA sequence of the beta supplement mapping phase, mm019, has been generated and will be uplinked Saturday March 4. The mm019 sequence will begin execution on 00-65 and continue through 00-68 (3/8/00). Included in the mm019 sequence is the first of the monthly off-nadir polar scans for the MOLA instrument, approved by the Program. The first 12 orbits of the mm019 sequence will fly with a -17.1 degree nadir off-point angle for 45 minutes centered about the South Pole and a 14.4 degree nadir off-point angle for 45 minutes centered about the North Pole. For the fixed-HGA mapping operations, the spacecraft will be nadir pointed for 24 hours, recording science data on the solid state recorders, then the spacecraft will be oriented to point the HGA bore-sight at Earth for an eight hour playback period to return the data collected on the recorders. During this eight-hour period, the spacecraft will not be nadir pointed and not collecting science data, with the exception of radio science which will perform atmospheric observations as the spacecraft enters and exits Earth occultation. As reported last week the reason for the fixed-HGA sequences is to provide radio science atmospheric observations near the South Pole as the spacecraft exits Earth occultation, a geometry not supported by the HGA gimbals in the beta supplement operations due to EMI and HGA boom interference constraints. Upon completion of the data playback at the end of the eight-hour Earth pointed period, the spacecraft will be turned back to nadir pointing to begin the next fixed-HG A cycle

Spacecraft Health:

All subsystems are reporting nominal health. Three more PDS reset occurred over the last week. The frequency has been increasing over the last two weeks. So far no cause has been found for the recurring resets. The resets appear to have minimal if any impacts to the instruments. We continue to forward all reset data to the PDS software experts at JPL.

Uplinks:

There have been 21 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm017 and mm018 sequences. Total command files radiated to the spacecraft since launch is 4480.

Upcoming Events:

The Navigation team has been looking at the ground track walk on a weekly basis to determine if an orbit trim maneuver (OTM) is required. Prior to the start of beta supplement operations, it appeared that an OTM would be needed sometime in March. However, the latest tracking data for the first few weeks of beta supplement operations shows the rate of the ground track walk decreasing and starting to knee over, which if the trend continues will not necessitate an OTM in the near term. With the likelihood of the next OTM diminishing, planning has begun for a focus calibration of the MOC to be performed in the next few weeks.


Wednesday, February 23, 2000 (DOY 047/19:00:00 to DOY 0454/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1206 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 328 days
Total Mapping Orbits = 4305
Total Orbits = 5987

Recent Events:

The pace of the new mapping Beta sequence generation problem, a build every week, and a realization of new operational constraints imposed by the new mapping scheme, has caused two sequencing errors over the last week.
On 00-048 (2/17/2000) at about 00:00 UTC, the new Beta Supplement sequence, mm014b, was scheduled to kickoff but never went active. Since that new sequence controls the tracking of the HGA to Earth, no downlink was possible. Using a 34-m HEF station, a command was successfully uplinked via LGR-2 to change the uplink rate from 125 bps to 7.8 bps. Then, at 7.8 bps, a mini-sequence was successfully radiated to auto-track the HGA for about 30 minutes per orbit for 4 consecutive orbits, allowing for a 4K real-time downlink. During the first of these orbits, spacecraft telemetry was obtained which showed that MGS was in a healthy condition. During the second of these orbits, the uplink rate was changed back to 125 bps and the new mm014c sequence was uplinked to resume normal operations. The mm014c sequence began execution nominally at 14:20 UTC and has successfully completed execution. The mm015 sequence, was uplinked and began execution on 00-051 (2/20/2000) at 00:00 UTC. The mm015 sequence is scheduled to run through 00-054 (2/23/2000). The net effect of the anomaly was the loss of most of DOY 48 recorded science telemetry.
The cause of the mm014 sequence anomaly was that it was loaded into the incorrect area of the sequence buffer, which was already executing the mm013 sequence. This error was induced by having to split the 7 day beta supplement sequence into two parts due to the size of the sequence and the much reduced uplink time available each orbit due to the complex HGA management. This splitting process introduced an ambiguity in the naming convention: mm013a was used for Part 1 of sequence 013 rather than revision level a, and mm013b was used for Part 2 of sequence 013 rather than revision level b. When a second revision of Part 1 was required, mm013c was used, since mm013b was already taken by Part 2. Due to the ambiguity in the naming convention, mm014 was run through SEQTRAN using the FINCON file from mm013c (Part 1) rather than mm013b (Part 2). The result was that mm014b was loaded into the same buffer area as Part 2 of the previous sequence. Since this previous sequence was still executing when mm014b was uplinked, the new sequence did not go active.

To confound matters, due to the current MGS to Earth range, we are not able to support two-way data (uplink and downlink data) at the high rate 40 ksps real-time downlink rate. Therefore all uplinks are currently performed during orbits in which the recorded data from the previous day is being played back. Therefore confirmation of a successful sequence uplink and activation requires waiting until the next day's data is played back. For this case there was insufficient time available to determine that the sequence load had been rejected and to rebuild a replacement sequence in time. This was due in part to a half-day loss in the schedule due to a problem with our spacecraft test lab (STL).
The second anomaly occurred with the development of the mm016a sequence, which was uplinked successfully to the spacecraft on 00-052 (2/21/200) and scheduled to begin execution on 00-055 (2/24/00) at 00:00 UTC. In this event an error in the recording and playback of the science data was discovered after the sequence had been uplinked. The sequence was successfully terminated on 00-054 (2/23/2000) at ~14:00 UTC and a replacement sequence, mm016b, uplinked several orbits afterwards upon confirmation of the termination of mm016a. The root cause for this anomaly was simply a rush to uplink the sequence early enough to verify its activation in order to avoid a repeat of the mm014 sequence anomaly.

Several changes have been made to the sequence development process for the weekly sequence builds. The first change, which was already going to be made for the next sequence anyhow, was to rename the sequences. The split of the weekly sequences into two parts creates two sequences, mm016 and mm017, for example, rather than mm016a and mm016b. The second and probably the most important change made was to increase the sequence development time by three days to provide sufficient time with margin for development, review, STL validation, uplink and verification of the sequences.

One final note, the failure to get a new sequence on-board the spacecraft poses no risk to the health of the spacecraft. The spacecraft will maintain mapping nadir pointing and articulation of the solar array. Communications from the spacecraft and collection of science data will be interrupted until a new sequence can be uplinked.

Spacecraft Health:

All subsystems are reporting nominal health. A sixth PDS reset occurred on 00-019. So far no cause has been found for the recurring resets. The resets appear to have minimal if any impacts to the instruments. We continue to forward all reset data to the PDS software experts at JPL.

Uplinks:

There have been 14 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm014, mm015 and mm016 sequences. Total command files radiated to the spacecraft since launch is 4459.

Upcoming Events:

The first fixed-HGA mapping sequence of the beta supplement era is scheduled for March 6 and development of this sequence has begun. One of the limitations of the mapping beta supplement scheme is a loss of South Pole radio science atmospheric data due to HGA gimbal constraints. The project approved a three to four day period each month to perform fixed-HGA operations, in which the HGA is pointed along the spacecraft +X axis and the spacecraft is moved to point the HGA to Earth for an eight-hour period (i.e. four orbits). During the eight-hour Earth pointed period the science data recorded from the previous 24 hours of nadir pointed mapping is played back. This scheme allow radio science observations to be made at Earth occultation ingress and egress, at the expense of collecting mapping data for the eight-hour Earth pointed period. The project also approved monthly MOLA nadir off-pointed polar observations. These observations will be performed during the 24 hour nadir pointing period prior to the first eight-hour fixed-HGA Earth pointed period.


Wednesday, February 16, 2000 (DOY 040/19:00:00 to DOY 047/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1199 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 321 days
Total Mapping Orbits = 4219
Total Orbits = 5901

Recent Events:

Beta Supplement operations continue nominally. The mm013 sequence is currently executing on the spacecraft. The next sequence, mm014, was uplinked to the spacecraft on Feb 15 at 18:25 GMT and is scheduled to go active at 00:00 GMT on Feb 17.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 30 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm013 sequence. Total command files radiated to the spacecraft since launch is 4445.

Upcoming Events:

The first fixed-HGA mapping sequence of the beta supplement era is scheduled for March 6. More details forthcoming.


Wednesday, February 9, 2000 (DOY 033/19:00:00 to DOY 040/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1190 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 314 days
Total Mapping Orbits = 4134
Total Orbits = 5816

Recent Events:

The mz041 mini-sequence, containing the "full-up" Beta Supplement HGA motion verification test, executed on Thursday Feb 3 at ~11:00 GMT. The test successfully moved the azimuth gimbal to 140°, then performed a "simulated orbit" on the elevation gimbal, incorporating a 3-part boom interference rewind and a 3-part range-of-motion rewind, and executed the full elevation range of motion from -157° to +155°. Based upon the success of the test, the first beta supplement mapping sequence, mm012, was radiated to the spacecraft and began executing Saturday Feb 4 at 00:00 GMT. The first beta supplement orbit executed on Monday Feb 7 at 10:00 GMT and all operations on the spacecraft and with the DSN station were completely nominal. Twenty-five orbits have been successfully executed as of the writing of this report.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 25 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm012 sequence. Total command files radiated to the spacecraft since launch is 4415.

Upcoming Events:

Uplink of the second beta supplement sequence, mm013, is scheduled for Thursday Feb 10.


Wednesday, January 19, 2000 (DOY 012/19:00:00 to DOY 019/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1169 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 293 days
Total Mapping Orbits = 3876
Total Orbits = 5558

Recent Events:

The mm011 sequence began execution on Jan 13 at 00:00 UTC and runs through Feb 4. The spacecraft continues to perform flawlessly in performing the nominal mapping mission.

The mz035 mini-sequence, containing scans for a third Pathfinder landing site image and two additional MPL landing site images finished execution on Jan 19 at 13:45 UTC. Unfortunately, bad luck struck again with regard to the Pathfinder opportunity and significant portions of the Pathfinder image were lost due to more DSN problems. There is no redundant capability to return the imaging data at the high 40000 bps real-time rate and also record the data to the solid state recorders for redundant playback the next day. Consequently, return of these landing site images is a single opportunity event which requires the DSN stations to be configured and working properly during the ~30 minute data return period. Hardware, weather and other factors with the stations contribute to make this far from a foolproof process. In general, the DSN has performed excellently in supporting the MGS mission.

A change request was approved by the Project to perform some HGA motion calibration tests for the Magnetometer team. These will be performed on the dark side of the planet and will have minimal effect on normal operations. The only exception is that Radio Science ingress data will be prematurely truncated on the calibration orbits. These HGA motions tests will be performed over 15 orbits, with the solar arrays being moved to different fixed positions during the HGA motions after every three orbits. Due to mini-sequence buffer size constraints, the 15 orbits will be performed in two parts. The mz036 mini-sequence was successfully transmitted to the spacecraft on Jan 19, to perform the first 9 orbits on Jan 20 and mz037 will be transmitted on Jan 21 to perform the remaining 6 orbits on Jan 21.

The Ka Band Link Experiment (KaBLE) was turned off on Jan 14, to reduce the spacecraft power loads. The KaBLE investigators are not currently utilizing the Ka Band data.

HGA Anomaly:

The HGA inner gimbal continues to decrease and is currently at 48.9 degrees. The inner gimbal angle will continue decreasing, reaching the location of the gimbal obstruction at 41.5 deg in early February. A special review was held on Jan 18 to discuss possible spacecraft testing to determine if the obstruction is still present. The recommendations from the review are expected by the end of the week. Any spacecraft testing would be performed over the next two weeks, prior to the start of beta supplement mapping operations.

Spacecraft Health:

All subsystems are reporting nominal health. A third Payload Data System (PDS) reset occurred on Jan 16. The reset data has been sent to JPL, who designed and built the PDS. The spacecraft team has been unable to correlate the data to any specific spacecraft activity.

Uplinks:

There have been 27 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, KaBLE turn off and the mz036 mini-sequence load. Total command files radiated to the spacecraft since launch is 4345.

Upcoming Events:

The preliminary first beta supplement sequence will begin development Jan 20 in preparation for the start of beta supplement mapping operations on Feb 5. Additional MPL and MPF imaging opportunities will continue through Feb 4. The next imaging mini-sequence will be built on Jan 21 and will contain all the desired over-flight opportunities through Jan 26.


Wednesday, January 12, 2000 (DOY 005/19:00:00 to DOY 012/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1162 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 286 days
Total Mapping Orbits = 3791
Total Orbits = 5473

Recent Events:

The mm010 sequence finishes execution on Jan 13 at 01:27 UTC. The next mapping sequence, mm011, has been uplinked to the spacecraft and will begin execution on Jan 13 at 00:00 UTC and continue executing through Feb 4. The mm011 sequence will be the last nominal mapping sequence of the baseline mapping mission. The next mapping sequence will be the first of the new beta supplement sequences, designed to continue mapping operations in the presence of the HGA obstruction at the 41.5 deg azimuth gimbal angle. Stay tuned for more information about the specifics of beta supplement mapping operations over the next few weeks

The mz034 mini-sequence was uplinked to the spacecraft on Jan 8 and finished execution on Jan 12 at 09:00 UTC. The mz034 sequence contained the second imaging scan of the Pathfinder landing site and four additional scans of the Mars Polar Lander landing site. The additional MPL landing site scans are intended to fill in gaps in the original imaging campaign performed prior to the holidays and to expand the coverage area to the west in response to the latest atmospheric data. Unfortunately bad luck asserted itself again on the second Pathfinder landing site image as the science data was lost due to DSN station problems. A third attempt to image the Pathfinder site is currently being planned. Additional imaging of the MPL landing site is currently being discussed to continue expanding the coverage area.

The spacecraft continues to behave flawlessly in performing nominal mapping operations and the multitude of imaging scans.

HGA Anomaly:

The HGA inner gimbal continues to decrease and is currently at 51.7 degrees. The inner gimbal angle will continue decreasing, reaching the location of the gimbal obstruction at 41.5 deg in early February. STL testing to validate the new beta supplement operations plan continues.

Spacecraft Health:

All subsystems are reporting nominal health.

Uplinks:

There have been 18 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads and the mm011a and mz034a sequences. Total command files radiated to the spacecraft since launch is 4318.

Upcoming Events:

1) The mm012 sequence development kickoff meeting is scheduled for Jan 18.

2) The mz035 mini-sequence to continue imaging the MPL and MPF landing sites is scheduled for development on January 13 and 14.

3) The mz036 mini-sequence to perform additional magnetometer instrument calibrations has been approved and will begin development Jan 17.


Wednesday, January 5, 2000 (DOY 356/19:00:00 to DOY 005/19:00:00 UTC)

Launch / Days since Launch = Nov 7, 1996 / 1155 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 279 days
Total Mapping Orbits = 3707
Total Orbits = 5389

Recent Events:

The mm010 sequence continues executing nominally the daily science record and playback events. The mm010 sequence runs through January 12.

The initial MPL landing site imaging campaign has been completed, with 19 targeted scans across the predicted 1-sigma MPL landing ellipse having been executed. Unfortunately no obvious signs of the lander or its parachute has been found at this time. Note that the definition of the landing ellipse continues to change as additional atmospheric data from MGS is factored in. As a result, the current landing site imaging mosaic may not reflect the latest landing site knowledge. Additionally there were some gaps in the mosaic due to lost data at the DSN stations. As a result, a second set of imaging scans is being planned to fill in the gaps and to expand the coverage area in response to the latest atmospheric data.

In addition to completing the MPL scans, a special targeted opportunity to image the Mars Pathfinder landing site was performed Sunday December 26 at 09:18 UTC. Unfortunately due to an error in the coordinate system used to derive the targeted attitude, the wrong site was imaged. A second opportunity to image the Pathfinder landing site occurs on Sunday January 9. The mz034 mini-sequence will be built on January 6 and 7 to perform the MPF and additional MPL landing site imaging, and will execute through January 12.

The spacecraft has behaved almost flawlessly in performing all of the imaging scans.

HGA Anomaly:

The HGA inner gimbal angle continues to decrease and is currently at 53.5 degrees. The inner gimbal angle will continue decreasing, reaching the location of the gimbal obstruction at 41.5 deg in early February. STL testing begun for validation of the HGA beta supplement operations plan, which will be used to perform mapping operations for the rest of the nominal mapping mission.

Spacecraft Health:

All subsystems are reporting nominal health. As reported previously, battery 2 switched from VT curve 2 to VT curve 1 as a result of performing the MPL scans. This was expected and resulted in slightly higher battery 2 temperatures. Upon completion of the initial MPL and MPF scans, the Battery 2 VT curve was switched back to VT2. Soon after though the flight software autonomously re-commanded battery 2 back to VT1, which is where we will leave it. The trend indicates that battery 1 will shortly switch to VT1 as well.

Uplinks:

There have been 42 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files and instrument command loads. Total command files radiated to the spacecraft since launch is 4300.

Upcoming Events:

1) The mm011 sequence is currently in development and is scheduled for uplink Monday January 10, with a sequence start time of January 13 00:00 UTC.

2) The mz034 sequence to continue imaging the MPL and MPF landing sites is scheduled for development on January 6 and 7, to begin execution on Sunday January 9.


MSOP-MGS Status Reports for 1999


Mars Surveyor Operations Program

Mars Global Surveyor