Terra Weekly Mission Status Update 24 — 30 Aug 2001

The Terra spacecraft is in nominal mode. All instruments are in nominal science mode.

Instrument operations are continuing smoothly on all 5 instruments. The MOPITT instrument continues to operate on one cooler with Chopper 3 in the fully open position. A report summarizing the recent Chopper 3 anomaly and its diagnosis will be released in several weeks. A report on the cooler displacer anomaly that occurred in May is also expected.

In its current operational state, MOPITT is unable to fully calibrate the data for two of the 4 operating channels as a result of the inoperative chopper. This will impact science analysis algorithms operating in the MOPITT science computing facility but will not require updates to algorithms operating in the science software at the Distributed Active Archive Center.

The MODIS instrument continues to operate in normal science mode on Side A (Command Processor A, Power Supply 1). MODIS data have recently been used extensively in conjunction with the efforts of government agencies and other organizations to deal with the effects of the numerous forest fires in the western United States.

On August 29 there was a planned 4-hour TDRSS outage (between 17:00 and 21:00z) at the Second TDRSS Ground Terminal to perform system upgrades. All of the science data dumps for Terra during this interval were successfully transitioned from TDRSS to the Alaska and Svalbaard Polar Ground Stations. There was no data loss.

Ground testing with the commercial ground terminal at Svalbaard (SKS) is underway. In ground testing with this station via DataLynx, an extra 6 bytes have been appended to each command issued from the EOS Operations Center (EOC). Ground testing will continue until this problem is fully diagnosed prior to any testing involving the issuing of NO-OP commands to Terra via the SKS ground station.

Plans

• MODIS Calibration Roll Maneuver on September 7
• Drag Make-up Maneuver on September 19