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Terra Weekly Mission Status Update
Weekly Update Archive April 13 - April 19, 2001 The Terra spacecraft is operating in Nominal Mode. All instruments are functioning well in Science Mode. Terra Command and Data Handling continues to operate nominally. A Master Oscillator Frequency Adjust was performed on April 19 (DOY 109) AT 19:30z. MODIS science data were lost on DOY 102 (April 12, 2001) due to an MDA2BITE failure (High Gain antenna Motor Drive Assembly upset) occurring at 13:17:12z, preventing MODIS Lockup Replay. On DOY 105 (April 15), there were back to back MDA2BITE trips (approximately 9 minutes apart). This resulted in a late acquisition but all science data were recovered. On DOY 109 (April 19) at 13:19z there was another MDA2BITE failure with no data loss. The Tracking and Data Relay Satellite System (TDRSS) is heavily subscribed to support the Space Shuttle and International Space Station for DOY 113 - 119 (April 23-29). Two SA antennas are dedicated almost full-time. The original TDRSS schedule for Terra during this interval has many conflicts. We are not meeting the baseline requirements for Terra access to TDRSS as outlined in the Detailed Mission Requirements (DMR) Document, but if all goes as planned, science data losses are not expected. The Terra Flight Ops Team's Planning and Scheduling Team is working with the NCC toimprove the schedule. As a result of the above, several Primary Science Playbacks will likely be taken via EPGN on DOY 113 - 119. Processing will be delayed, as the data will not come via TDRSS. The EOS Data and Operations System (EDOS) should expect more Science Playbacks than usual during the interval while the Space Shuttle is on orbit. Playback timing will be driven by TDRSS availability, not by the Flight Ops Team's choice. No MODIS Roll Maneuver will be scheduled for April or May. The MISR team is taking part in the ACE-Asia campaign during April. ISSUES: The ASTER Instrument Operations Team has agreed to the proposed incremental lowering of the Shortwave Infrared (SWIR) Capillary Pumped Heat Transport System set point but discussions are still being held as to when this would occur. The temperature change will not be implemented until ASTER instrument team personnel can travel from Japan to GSFC to be present when the temperature adjusts are made. This may be several months (in June or July) due to schedule and budgetary issues. The delay poses no threat to the SWIR hardware. PLANS:
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