Mars Global Surveyor Status Report
30 May 2001
(Source: Jet Propulsion Laboratory)
(DOY 143/19:00:00 to DOY 150/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 1666 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 790 days
Total Mapping Orbits = 9,957
Total Orbits = 11,640
Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm142 sequence executed successfully from 01-144 (5/24/01) through 01-146 (5/26/01). The mm143 sequence has performed well since it started on 01-147 (5/27/01). It terminates on 01-150 (5/30/01). The mm144 sequence, successfully uplinked on 01-149 (5/29/01), begins executing on 01-151 (5/31/01).
Other - Nine more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 107 ROTOs to date.
All subsystems report good health and status.
The Sun Monitor Ephemeris fault protection continues to be disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.
There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequence mz103.
Three solar array position management scripts were updated to offset the commanded solar array positions by 35 degrees instead of the previous offset of 25 degrees. The update should extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays.
There have been 5,406 command files radiated to the spacecraft since launch.
DOY 01-172 (6/21/01) marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Nominal mapping sequences will not be as command intensive as the beta-supplement sequences. Therefore, 28-day background sequences will be the norm instead of the 3 and 4 day beta-supplement sequences.
Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-180 (6/29/01).