Terra Weekly Mission Status Update

Weekly Update Archive

March 18 - 24, 2005

The Terra spacecraft is operating nominally in science mode. Terra automation development continues to work towards SRR.

On March 18, 2005, the CAT developer gave a one-on-one demo of his GMSEC tool with key FOT members. The idea is to develop a single set of rules (in CAT) that digest procedure “templates.” These templates will be developed by the FOT and their purpose is to provide instruction on how to run a procedure. Therefore, procedures themselves will not change (this is key from a CM standpoint). What will change is the creation of these templates that (like the operator) contain instructions on how to 'run' a procedure. CAT (in this case) will be used to digest and execute these templates.

Mission Impact Report
Two 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). There was no impact to science objectives and no data loss.

Ground System and Data Processing System Anomalies/Issues:
One MIR occurred this week having to do with a forward rate mismatch that resulted in the inability to command the spacecraft. Since both MODIS and MISR buffers were near full when this occurred, the delay in commanding caused the MISR buffer to disable. Partial playbacks were made to recover data, but some MISR data were lost. Further investigation is needed.

One MIR occurred this week having to do with a late acquisition with TDE. There was no impact to current science objectives and no science data loss.

One MIR occurred this week having to do with a coherency scheduling conflict with White Sands. White Sands was scheduled for a non-coherent event and we were expecting coherency. The mix-up was on our side and was easily remedied through a Ground Contact Message Request (GCMR) to White Sands to switch to coherent. There was no impact to science objectives and no data loss.

One MIR occurred this week having to do with S-band dropouts. One dropout occurred during a handover contact from AGS to SKS. Mutual interference was suspected. These dropouts lasted approximately 4 minutes. Although science playback was delayed, there was no impact to science data as it was dumped successfully during the SKS contact.

One MIR occurred this week having to do with a higher than expected bit error rate on the S-band, Q channel as seen from our end. White Sands did not report a problem. Although this frequency/channel is seldom used for anything other than diagnostics, this remains under investigation.