Mars Global Surveyor Status Report 20 June 2001

Wednesday, June 20, 2001 (DOY 164/19:00:00 to DOY 171/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1687 days

Start of Mapping / Days since Start of Mapping = April 1, 1999 / 811 days

Total Mapping Orbits = 10,214

Total Orbits = 11,897

Recent Events:

Background Sequences – The spacecraft is operating nominally in performing
the beta-supplement daily recording and transmission of science data. The
mm148 sequence executed successfully from 01-165 (6/14/01) through 01-167
(6/16/01). The mm149 sequence has performed well since it started on 01-168
(6/17/01). It terminates on 01-171 (6/20/01). The mm150 sequence,
successfully uplinked on 01-170 (6/19/01), begins executing on 01-172
(6/21/01). The start of mm150 marks the end of the beta-supplement phase and
the beginning of the nominal mapping phase of the mission. Planetary and
orbital geometry will allow the HGA to auto-track the Earth without
impacting the HGA boom. Therefore, background command sequences can take
advantage of the on-board command scripts originally designed for the
nominal mapping mission. 28-day background sequences will become the norm
instead of the 3 and 4 day beta-supplement sequences.

Other – Eleven more Roll Only Targeted Observations (ROTOs) were performed
since the last report. MGS has completed 137 ROTOs to date.

Spacecraft Health:

All subsystems report good health and status.

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 mz109 & mz110. We also updated Solar Array AEM Script #1
timing to avoid potential electromagnetic interference (EMI) with the solar
arrays during HGA transmissions to Earth. There have been 5,449 command
files radiated to the spacecraft since launch.

Upcoming Events:

Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford
University between 01-177 (6/26/01) and 01-179 (6/28/01). MOLA Polar Scans
are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01).