Less than three weeks remain until Mars Global Surveyor completes its 10-month voyage to reach the red planet. Surveyor continues to perform flawlessly as it closes the 5.04 million kilometer distance to Mars at a rate of 245,200 kilometers per day.
The flight team spent the majority of this week controlling the spacecraft for a series of long-range observations of Mars. On eight separate occasions from Tuesday through Thursday, Surveyor rotated into a position that pointed the science instruments directly at Mars for a time period of one hour per occasion. These observations were staggered in time to allow the Mars Orbiter Camera to image the planet at longitude increments of 45 degrees.
Initial looks at the images returned from the camera revealed a half-illuminated planet as seen from the spacecraft. Within these images, Mars occupies approximately 325 pixels at a resolution of slightly greater than 21 kilometers per pixel element. This resolution is comparable to the best images returned from the Hubble Space Telescope in Earth orbit. After Surveyor reaches its proper mapping orbit around the red planet, the camera will be able to obtain images with a resolution of up to 1.4 meters per pixel.
The camera team, led by Dr. Michael Malin, is currently processing the raw data from the camera and will release the images in a press conference on Tuesday, September 9th. However, Dr. Malin will also perform a quick process on one or two of the images for public release on the Surveyor web site next early next week.
In addition to the camera, the Thermal Emission Spectrometer science instrument also observed Mars during the imaging opportunities that took place this week. Initial results showed that the spectrometer detected carbon dioxide from the Martian atmosphere. Although this result was expected, it confirmed that the spectrometer is functioning properly. The spectrometer team, led by Dr. Phil Christensen of Arizona State University, will spend the next few weeks processing their data for more detailed results.
Today, the flight team transmitted the C11 command sequence to Surveyor. The sequence will activate on Monday, August 25th at 7:00 a.m. PDT and will control the spacecraft for the next eight days. The most important activity in C11 will be a short thruster firing to refine the spacecraft's flight path to Mars. This trajectory correction maneuver will be the third and last maneuver executed between launch and arrival at Mars.
After a mission elapsed time of 288 days from launch, Surveyor is 234.36 million kilometers from the Earth and is moving in an orbit around the Sun with a velocity of 21.85 kilometers per second. This orbit will intercept Mars 20 days from now, slightly after 6:00 p.m. PDT on September 11th (01:00 UTC, September 12th). The spacecraft is currently executing the C10 command sequence, and all systems continue to be in excellent condition.
Status report prepared by:
Office of the Flight Operations Manager
Mars Surveyor Operations Project
NASA Jet Propulsion Laboratory
California Institute of Technology
Pasadena, CA 91109