Beginning in October 2022, Terra will exit the spacecraft constellation that has been its home for the last twenty years and continue operations at a lower orbit altitude. To assure instrument health and safety, Terra/MODIS will be commanded to a modified configuration with SMIR and LWIR focal planes turned off, blackbody calibrator turned off, along with space view and nadir doors closed. MODIS will remain in this configuration throughout the duration of the constellation exit maneuvers.
Aqua S/C transitioned to a safe mode on March 31st, 2022 (2022090). Post the S/C recovery, MODIS was brought back to Science Mode on April 14th, 2022 (2022104). Increase in the PV LWIR TEB electronic crosstalk was observed post-safe mode that resulted in increased striping in the L1B imagery. MCST developed a crosstalk correction algorithm and LUTs for the PV LWIR TEB to be applied Aqua MODIS C6.1 for forward production starting 2022208.0000 under version 6.2.3.
As an FYI, MCST continues to monitor the impact of the Aqua safe mode event earlier this year. We have noted changes in the SWIR bands (bands 5-7 and 26).
Band 6 detector 4 (product order) has been marked dead in the QA LUT as of 2022090.1600 (March 31, 2022). This update was delivered for processing on June 15, 2022, so additional processing will be required for this change to be made in historic data.
We are continuing to monitor the remaining SWIR detectors for any further changes in performance.
The Aqua spacecraft entered a safe state after an unexpected power controller swap on March 31, 2022 (2022/090 @17:59:08z). This caused the MODIS instrument to also enter safe mode. After analysis and recovery of the spacecraft, MODIS was transitioned to full science mode via outgas from April 13-15, 2022. Aqua MODIS returned to nominal temperatures and operational status for all bands on April 17, 2022 03:00:00z. MCST will perform additional calibrations and will continue to monitor the performance of the detectors following the safe mode event.
At the two links below, you can find the latest information on the timelines of the Terra and Aqua Constellation exits.