Mars Global Surveyor Status Report 19 Sep 2001

Wednesday, September 19, 2001 (DOY 255/19:00:00 to DOY 262/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1778 days

Start of Mapping / Days since Start of Mapping = April 1, 1999 / 902 days

Total Mapping Orbits = 11,327

Total Orbits = 13,010

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 01-156 (9/13/01). It terminates on 01-290
(10/17/01).

Other – MOLA Diagnostic Test #4 was performed on 01-256 (9/13/01). The MOLA
team is in the process of analyzing the resulting data.

Roll Only Targeted Observations (ROTO) 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 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 continues
to investigate the STAREX anomaly that caused the 9/6/01 C-Mode entry. The
MOLA instrument team is still investigating the MOLA anomaly of 01-181
(6/30/01). The MOC instrument required a hardware reboot to recover from an
anomaly that temporarily prevented it from returning properly formatted
science data.

Uplinks:

There have been 28 uplinks to the spacecraft during the past week, including
new star catalogs and ephemeris files, TES instrument turn-on, MOC
instrument re-boots, and standard instrument command loads. 5,755 command
files have been radiated to the spacecraft since launch.

Upcoming Events:

Delta-DOR experiments are scheduled for 01-267 (9/24/01) and 01-269
(9/26/01).