Mars Global Surveyor Status Report
18 Dec 2001
(Source: Jet Propulsion Laboratory)
(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
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.
All subsystems report good health and status.
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.
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.