Terra Weekly Mission Status Update September 21 – September 27, 2001
The Terra spacecraft is in nominal mode. All instruments are in nominal science mode.
Instrument operations are continuing smoothly on all five instruments. ASTER representatives will meet with Terra personnel next week to discuss plans for Direct Downlink to Japan’s ground station now under development.
Orbit analysis shows that the next Drag Make-up Maneuver for Terra will be required on October 2. This maneuver will be shorter in duration than desired to prevent violating a self imposed drift rate restrictions of 1.5 km/day. This maneuver is conservative, requiring the next burn earlier than usual.
On September 19, there was a negative acquisition with TDRS Spare. Analysis shows that a telemetry spike occurred at beginning of contact. The current spiked for one sample then returned to a lower than desired level until end of contact. No other contacts have been affected since or prior to this event. There have been a small number of previous spikes experienced previously, but all spikes occurred during back orbit. An anomaly team is being assembled to investigate the spikes.
Several MDA2BITE trips (High Gain Antenna Motor Drive Assembly opto-coupler Single Event Upsets) occurred during this reporting period with no resultant non-recoverable data loss. The majority of the MDA bite trips seems to be related to the large solar coronal mass ejection that occurred on September 24.
Plans:
- Next Drag Make-up Maneuver on October 2
- Next MODIS Calibration Roll Maneuver on October 7
- Planning and Simulations in progress for Terra Inclination Adjust Maneuver
