Status Report

Mars Global Surveyor Status Report 26 Sep 2001

By SpaceRef Editor
September 26, 2001
Filed under , ,

Mars Global Surveyor Status Report

Wednesday, September 26, 2001 (DOY 262/19:00:00 to DOY 269/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1785 days

Start of Mapping / Days since Start of Mapping = April 1, 1999 / 909 days

Total Mapping Orbits = 11,412

Total Orbits = 13,095

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing
daily recording and transmission of science data. The mm153 sequence has
performed well since it started 01-256 (9/13/01). It terminates on 01-290

Other – Delta-DOR experiments were performed on 01-267 (9/24/01) and 01-269

No Roll Only Targeted Observations (ROTOs) were performed this past week.
ROTOs were temporarily suspended pending investigation of the C-Mode entry
root cause. MGS entered C-Mode on 9/6/01 because the STAREX star processing
software could not converge on a good inertial attitude following a ROTO.
The ROTO did not cause the C-Mode entry, but STAREX performance following
ROTOs may impact how we perform ROTOs in the future. MGS has completed 198
ROTOs to date.

Spacecraft Health:

All subsystems report good health and status. The spacecraft team is
investigating ways to improve the probability that STAREX will converge on a
good inertial attitude following each ROTO. The MOLA instrument team is
still investigating the MOLA anomaly of 01-181 (6/30/01) and will be
requesting a fifth diagnostic test in the near future.


There have been 16 uplinks to the spacecraft during the past week, including
new star catalogs and ephemeris files, instrument command loads, and the
MZ136A ROTO mini-sequence. 5,771 command files have been radiated to the
spacecraft since launch.

Upcoming Events:

On 01-270 (9/27/01), MGS will perform a ROTO during a communications orbit
for the first time. Previously, MGS had been restricted to performing ROTOs
only during non-communications orbits. Two more ROTOs during communications
orbits are scheduled for the MZ037 mini-sequence.

A Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline
diagnostic test will be performed on 01-278 (10/05/01). It is designated
MZ139. Performing this test periodically should give us insight into any
additional SA hinge or HGA gimbal degradation, if it occurs.

SpaceRef staff editor.