(DOY 262/19:00:00 to DOY 269/19:00:00 UTC)

Launch / Days since Launch = Nov. 7, 1996 / 1785 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 909 days
Total Mapping Orbits = 11,412
Total Orbits = 13,095

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 01-256 (9/13/01). It terminates on 01-290 (10/17/01).

Other - Delta-DOR experiments were performed on 01-267 (9/24/01) and 01-269 (9/26/01).

No Roll Only Targeted Observations (ROTOs) were performed this past week. ROTOs 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 following ROTOs 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 is investigating ways to improve the probability that STAREX will converge on a good inertial attitude following each ROTO. The MOLA instrument team is still investigating the MOLA anomaly of 01-181 (6/30/01) and will be requesting a fifth diagnostic test in the near future.

Uplinks:

There have been 16 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the MZ136A ROTO mini-sequence. 5,771 command files have been radiated to the spacecraft since launch.

Upcoming Events:

On 01-270 (9/27/01), MGS will perform a ROTO during a communications orbit for the first time. Previously, MGS had been restricted to performing ROTOs only during non-communications orbits. Two more ROTOs during communications orbits are scheduled for the MZ037 mini-sequence.

A Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline diagnostic test will be performed on 01-278 (10/05/01). It is designated MZ139. Performing this test periodically should give us insight into any additional SA hinge or HGA gimbal degradation, if it occurs.