Mars Global Surveyor Status Report 26 Jun 2002
Mars Global Surveyor Status Report
Wednesday, June 26, 2002 (DOY 170/19:00:00 to DOY 177/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 2058 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1183 days
Total Mapping Orbits = 14,751
Total Orbits = 16,434
Recent Events:
Background Sequences – The spacecraft is operating nominally in performing
the beta-supplement daily recording and transmission of science data. The
mm188 sequence executed successfully from 02-171 (6/20/02) through 02-173
(6/22/02). The mm189 sequence has performed well since it started on 02-174
(6/23/02). It terminates on 02-177 (6/26/02). The mm190 sequence,
successfully uplinked on 02-176 (6/25/02), begins executing on 02-177
(6/26/02).
Other – On 02-172 (6/21/02) and 02-177 (6/26/02), DSS-15 performed
acquisition and tracking tests with MGS to characterize the current
performance capabilities of both MGS receivers. Updating our knowledge of
the acquisition and tracking performance of the receivers will allow us to
update the uplink sweep parameters for MGS.
Seven Roll Only Targeted Observations (ROTOs) were performed successfully by
the mz181 & mz182 minisequences. MGS has completed 260 ROTOs to date.
Spacecraft Health: All spacecraft subsystems report good health and status.
Similar to last week, the star identification software had some difficulty
identifying stars following two of the ROTOs. The flight software
modifications we made several weeks ago continue to work as designed and
STAREX converged after autonomously resetting. We have instituted a process
that should improve STAREX performance by modifying the star catalog when we
determine that problematic stars are about to enter the CSA field of view.
Uplinks:
There have been 23 uplinks to the spacecraft during the past week, including
new star catalogs and ephemeris files, instrument command loads, the mz182
and mz183 ROTO mini-sequences, and the mm189 and mm190 background sequences.
6,828 command files have been radiated to the spacecraft since launch.
Upcoming Events:
ROTOs are planned for next week in the mz183 and mz184 mini-sequences.
