A mission milestone was reached today as the flight team celebrated the one-year anniversary of the launch of Mars Global Surveyor. During the previous year in flight, the spacecraft has completed a 10-month, 435-million-mile (700-million-kilometer) journey to reach Mars, followed by 36 revolutions around the planet.
Science results to date have included photographs of gigantic volcanoes and canyons, the discovery of local magnetic fields, topography measurements throughout the northern hemisphere, and thermal measurements of the atmosphere and surface. Some of the latest scientific observations will be presented at a press conference on Monday, November 10that 10:00 a.m. PST. Material from the conference will be available for download from the Surveyor web site early next week.
Today also marked the return to aerobraking operations after a one- month hiatus. At 1:51 p.m. PST, the onboard flight computer commanded Surveyor's tiny thruster rockets to fire for 50 seconds. This burn occurred at the high point of the 36th orbit around Mars and slowed the spacecraft by 4.3 miles per hour (1.9 meters per second). As a consequence, the low point of the orbit was dropped from its current altitude of 109.1 miles (175.6 kilometers) down to 83.7 miles (134.8 kilometers).
When Surveyor reaches the new low point of the orbit early Saturday morning, it will skim through the upper Martian atmosphere for about 300 seconds. During this aerobraking pass, the air resistance pressure experienced by the spacecraft's solar panels will be 12 times less than that proposed by the original mission plan. Over the next week, the flight team will gradually increase the amount of atmospheric pressure experienced during aerobraking by further lowering the orbit's low point.
After a mission elapsed time of 365 days from launch, Surveyor is 181.16 million miles (291.55 million kilometers) from the Earth and in an orbit around Mars with a high point of 28,016 miles (45,088 km), a low point of 83.7 miles (134.8 km), and a period of 35.4 hours. The spacecraft is currently executing the P37 command sequence, and all systems continue to perform as expected.
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