Mars Global Surveyor Status Report 25 Apr 2001

Wednesday, April 25, 2001 (DOY 108/19:00:00 to DOY 115/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1631 days

Start of Mapping / Days since Start of Mapping = April 1, 1999 / 755 days

Total Mapping Orbits = 9,530

Total Orbits = 11,213

Recent Events:

Background Sequences — The spacecraft continues to operate nominally in
performing the beta-supplement daily recording and transmission of science
data. The mm132 sequence executed successfully from 01-109 (4/19/01) through
01-111 (4/21/01). The mm133 sequence has performed well since it started on
01-112 (4/22/01). It terminates on 01-115 (4/25/01). The mm134 sequence,
successfully uplinked on 01-114 (4/24/01), begins executing on 01-116
(4/26/01).

Other – MGS transmitted high frequency spacecraft body rate data to Earth on
01-115 (4/25/01). The data will provide insight into the health of the -Y
solar array hinge and the effects of solar array motion on TES data. MGS has
performed 75 Roll Only Targeted Observations to date.

Spacecraft Health:

All subsystems report nominal health.

Uplinks:

There have been 12 uplinks to the spacecraft during the past week, including
instrument command loads, the background sequences cited above, and ROTO
mini-sequences mz091 through mz092.

The last two of three solar array position management scripts were modified
to offset the commanded solar array positions by 25 degrees. Our goal is to
extend the life of the Partial Shunt Assemblies by reducing the amount of
excess power generated by the solar arrays.

There have been 5,270 command files radiated to the spacecraft since launch.

Upcoming Events:

The mm135 background sequence will be uplinked on 01-117 (4/27/01). MOC
Defocus Calibration Scans will be performed by the mm134 and mm135 sequences
between 01-116 (4/26/01) and 01-123 (5/02/01). Radio Science Occultation
Egress Scans are scheduled for 01-132 (5/12/01) and 01-133 (5/13/01). ROTO
mini-sequences mz092 and mz093 will execute this next week.