Terra Mission Status Update

Status Update Archive

August 18 - August 24, 2006

On August 22, 2006 from 16:37:54 to 19:14: 51 UTC, the Space View Door (SVD) and Nadir Aperture Door (NAD) on the EOS Terra Moderate Resolution Imaging Spectroradiometer (MODIS) instrument were unintentionally commanded closed on the Terra spacecraft. This command sequence was intended for the other MODIS installed on the Aqua satellite. The commands were mistakenly included in the stored command load prepared for the Terra spacecraft. The error was not identified prior to upload or stored command execution. The problem was detected after the Flight Operations Team (FOT) Online engineer recognized the yellow limit violation caused by the warming of the Cold Focal Plane Assemblies (CFPA) and notified the MODIS Instrument Operations Team (IOT). Upon telemetry inspection, the MODIS IOT identified the closed doors as the cause of the warming CFPAs. During the next contact, the MODIS doors were commanded open. The SVD was opened at 19:13, and the NAD was opened at 19:15. Useable science data was not captured while the doors were closed or during the detector cool down period that followed. The MODIS team is assessing the impact to the detectors - early indications are good. An Anomaly meeting was held on Wednesday, August 23. Participants included the Terra Project Scientist, the MODIS Project Scientist, the MODIS operations engineers, and the Terra Flight Operations Team. Root cause, contributing factors, and corrective actions will be determined. Corrective actions will include more diligent load checks.

Terra Automation Working Group met this week and continues progress on the new system.

The ASTER Direct Downlink (DDL) testing is waiting for the EROS Data Center to develop the appropriate Viterbi decoder processing algorithm.