Mars Global Surveyor Spacecraft has entered contingency mode

The Mars Global Surveyor Spacecraft entered contingency mode on 27 February and as of 5 March 2002 had not been sufficiently recovered to resume normal daily global monitoring.

MGS has entered “C-mode” four times since the beginning of the extended mission (May, September, October 2001, and March 2002). The proximal cause of C-mode entry was errors in the attitude control system’s processing of star observations made by the Celestial Sensor Assembly.

Recovering the spacecraft to normal operations has taken one week, following all four upsets.

The present upset and delayed recovery was unfortunate because it precluded continuous weather monitoring during the period exactly one Mars year prior to the arrival and operations of the Mars Exploration Rovers.