Terra Weekly Mission Status Update

Weekly Update Archive

March 25 - 31, 2005

The Terra spacecraft is operating nominally in science mode.

All Terra Remote EOS Operations Center (REOC) activities at Wallops were successfully achieved this week. This includes Tic/Tocs, Alog, SSR replay, SSR playback, ATC load, and NAV load, which were all conducted from the REOC.

Status of Key Upcoming Schedule Milestones:
On 3/29/05, the CAT developer gave a follow-on demo of his GMSEC tool again with key Flight Operations Team (FOT) members. The previous week, Jamie Pawloski had given the CAT developer a flowchart of how he would like CAT to handle procedure 'templates'. For this demo, a set of CAT rules had been written to accommodate this flowchart. It is now up to the FOT to test and expand these rules to then decide if this is a viable approach for emulating online operators/engineers.

The latest MMS patches were made operational this week. Several days of ATC loads were successfully made. Plans are to give the OK on Friday (April 1) for late change generation.

Spacecraft Activities/Anomalies/Issues:
Two Mission Impact Reports (MIRs) occurred this week having to do with the High Gain Antenna Motor Drive Assembly (MDA2) BITE failures while in the South Atlantic Anomaly (SAA). During one of the MIRs, there was data loss of 112 EDUs from MISR. This was because the MDA2 BITE failure occurred during a science playback. There was no impact to science objectives and no data loss on the second MIR.

Ground System and Data Processing System Anomalies/Issues:
One MIR occurred this week having to do with the inability to send the initial command for a MODIS replay. The command did leave GSFC, but was not performed by spacecraft. Suspect a bit-flip occurred which caused rejection of command. Subsequent commanding worked as planned and MODIS replay was nominal. Therefore, there was no impact to science objectives and no data loss. However, this problem requires further investigation.

1 MIR occurred this week having to do with the prime CRP down during a pass. There was no telemetry on 000 port. Since all objectives had already been met before this problem, a failover to secondary port 100 was not made. A reset of gsips was made along with reconfiguration of erps which restored CRP functionality. No reason is yet known why the CRP went down, but is under investigation.

1 MIR occurred this week having to do with a ground configuration system anomaly where there was a failover to the OPS LAN due to telemetry freezing on the support LAN. This occurred while performing a MODIS replay. Although no data was lost, there were problems recycling the configs. Further investigation is needed.