Terra PWA Failure - 2020 October 5
The Terra spacecraft experienced a PWA (printed-wire assembly) failure on Monday, October 5, 2020. The incident was noted by the Terra flight operations team at 15:21:12z. As part of the recovery, science recording was disabled on October 6 (2020/280) at 03:32:56z to handle the moving of the supersets and was re-enabled at 03:41:56z.
The failed PWA was allocated to MODIS for science data recording. With the loss of the PWA, MODIS has less memory to record data. To account for the loss of memory, MODIS IOT has altered the Day/Night formatter rate. This reduces the amount of day rate data leading to reduction in the amount of data recorded using the reflective solar bands (RSB). The initial change reduces the day/night rate from 50/50 to 40/60, centered on the equator.
MODIS IOT is working to implement a more dynamic method of scheduling the rate changes to provide more coverage using the RSB.