Mission Profile
The 20 day launch window for Mars Surveyor 2001 Orbiter opens on 7 March 2001. After a nine month cruise the spacecraft will reach Mars between 10 and 23 December 2001. The spacecraft will use an aerocapture maneuver, involving a grazing entry into the martian atmosphere at a minimum altitude of 46 km on arrival. The aerobraking will take place for a maximum of 800 seconds. On exiting the atmosphere, the craft will be in a 500 x 100 km orbit. A periapsis raise maneuver will be performed after atmospheric exit to put the orbiter in a 500 x 200 km orbit. The solar arrays will then be deployed. A second periapsis raise performed 47 minutes after aeroexit will put the orbiter in a circular 500 km orbit. Seven days of checkouts and orbit refinements will put the spacecraft into a 400 x 400 km science orbit with an inclination of 92.91 degrees, a period of about 118 minutes, and a local mean solar time (LMST) of the descending node of 4:30 PM. The ground track will repeat to within about 0.2 degrees (12 km) every 25 orbits. It will remain in this orbit for the first 500 days. After this a small inclination change will be initiated which will begin a slow precession of the LMST from 4:30 PM to 6:00 PM. No science observations are scheduled after day 1100, but the orbiter will continue to be used as a communications relay through its 5 year nominal lifetime. Two uplinks a day are expected from the Mars Surveyor 2001 Lander.