Terra Weekly Mission Status Update

Weekly Update Archive

December 3 - 9, 2004

The sixth Terra re-engineering meeting was held on December 7, 2004. The goal is to design additional automation using the data quality and quantity information passed from the EOS Data and Operations (EDOS) system to the spacecraft command and control system.

On Dec. 7, a Terra thruster gain change teleconference was held with members of both the Flight Operations Team (FOT) and Lockheed Martin (Valley Forge). The plan is to run at least two simulations (by January 20, 2005) to test a proposed new thruster gain change against a low tank pressure of 90 psi.

Two Mission Impact Reports (MIRs) were written on High Gain Antenna Motor Drive Assembly (MDA2) BITE failures while in the South Atlantic Anomaly (SAA). In all cases there was no impact to science objectives and no data loss.

One Mission Impact Report (MIRs) was written on K-band dropouts with TDS during science data playback. This is a common problem that occurs more frequently (1-2 times per week) this time of year. In any event, no science data were lost due to replaying data during the same TDRS contact.

One Mission Impact Report (MIR) was written on late acquisition of signal (AOS). A call to WSC was needed to re-acquire TDRS 171. There was no impact to science objectives and no data loss.

One Mission Impact Report (MIR) was written on frame synchronization loss during science playback. This problem first appeared similar to one in September with SFE-A losing data clock synchronization. On the next pass, the FOT sent re-sync commands and science data flowed normally. However, during a subsequent pass, frame sync was lost again and WSC determined there was a problem with one of their high rate data switches. WSC swapped out the bad switch and data has continued to flow nominally. In any event, no science data was lost or impacted.

The MOMS Transition Receiving Review (TRR) is scheduled for Thursday. The scheduled transition of the ECS contract to the MOMS contract is planned for January 15, 2005 (Aura launch plus 180-Days). The FOT will transition on December 20, 2004.