From: Jet Propulsion Laboratory
Posted: Wednesday, April 18, 2001
Mars Global Surveyor Status Report
Wednesday, April 18, 2001 (DOY 094/19:00:00 to DOY 108/19:00:00 UTC)
This report covers two weeks.
Launch / Days since Launch = Nov. 7, 1996 / 1624 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 748 days
Total Mapping Orbits = 9,444
Total Orbits = 11,127
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm128, mm129, and mm130 sequences executed successfully from 01-095 (4/05/01) through 01-104 (4/14/01). The mm131 sequence has performed well since it started on 01-105 (4/15/01). It terminates on 01-108 (4/18/01). The mm132 sequence, successfully uplinked on 01-107 (4/17/01), begins executing on 01-109 (4/19/01).
Other - MGS successfully performed twelve Radio Science Occultation Egress Scans on 01-095 (4/5/01) and 01-096 (4/6/01). They were contained in the mz085 mini-sequence. MGS has performed 65 Roll Only Targeted Observations to date.
All subsystems report nominal health.
There have been 30 uplinks to the spacecraft during the past two weeks, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, a thruster accumulator reset command, and ROTO mini-sequences mz086 through mz090.
Commands were uplinked to modify the Reaction Wheel Assembly fault protection software and associated scripts. The modified response will allow a quicker recovery should another reaction wheel fail.
The first of three solar array position management scripts was 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. We will update the other two scripts after verifying the expected spacecraft performance under the first script.
There have been 5,258 command files radiated to the spacecraft since launch.
The mm133 background sequence will be uplinked on 01-110 (4/20/01). On 01-115 (4/25/01) of that sequence, MGS will transmit high frequency spacecraft body rate data to Earth. The data will provide insight into the health of the -Y solar array hinge and the effects of solar array motion on TES data. 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 mz090 and mz091 will execute this next week.
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