AIRS/AMSU-A instrument anomoly notification

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kathys
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Joined: Tue Jun 22, 2010 4:51 pm

AIRS/AMSU-A instrument anomoly notification

Post by kathys »

Subject: AIRS Operations Status Report (interim) for September 26, 2016

This is an interim AIRS operations status report.
There were two anomalies that affected the AIRS / AMSU-A team this past weekend.

At approximately 19:47 UT on September 24 (12:47 pm Pacific time) quiet bus power to the AMSU-A2 instrument turned off. At the same time, most telemetry from AMSU-A2 stopped updating. A few analog temperature parameters continue to update. They indicate that receiver, scan motor, and warm load temperatures have dropped from a nominal range of 12 – 16 degrees C to recent values of approximately -10 to -4 degrees C. The tentative recovery plan is: 1) turn on the survival bus to bring temperatures up as much as possible; and 2) run the AMSU-A2 startup procedure.

At approximately 03:25 UT on September 25 (10:25 pm September 24 Pacific time), a little less than 8 hours after the AMSU-A2 quiet bus power loss, Cooler B and focal plane temperatures began to rise, indicating that Cooler A’s compressor stopped. The focal plane temperature rose from its nominal value of 58 K to about 68 K.
The AIRS instrument was commanded to READY mode at 15:47 UT September 25. Data from the time of the anomaly until the Ready mode command are invalid, but have not been so marked and may make it into processing streams. All that data should be considered suspect.

All AIRS components, with the exception of Cooler A’s compressor, remain on and are in no danger. A recovery plan has been developed and is under review now. It will likely take several days to execute.
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William Mathews - AIRS Instrument Operations
NASA / Jet Propulsion Laboratory
office: (818)354-2421 cell: (323)459-1635
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