Topic: S-NPP VIIRS Lunar Calibration Roll Maneuver Scheduled for February 15, 2019.

Date/Time Issued: February 14, 2019 19:21Z

Product(s) or Data Impacted: All S-NPP Sensor Data

Date/Time of Initial Impact: February 15, 2019 21:30:05Z

Date/Time of Expected End: February 15, 2019 22:26:05Z

Length of Outage: See Details.

Details/Specifics of change: On February 15, 2019, S-NPP will perform a spacecraft attitude maneuver for the VIIRS Lunar Calibration, with a roll of -1.677 degrees centered at 21:53:05Z. Science data may be impacted while the spacecraft is pointing off-nadir during the attitude maneuver and the CERES instrument will not provide nominal science data as it will placed in a contamination safe mode. The timeline of events for this maneuver are provided below.

The following observatory systems will be affected:

21:30:05 Z M-bM-^@M-^S 22:26:05 Z M-BCERES will be in Contam-Safe, science data will not be available

21:45:05 Z M-bM-^@M-^S 22:01:05 Z M-BHRD will be off, data for direct broadcast users will be unavailable

21:49:35 Z M-bM-^@M-^S 21:56:34 Z M-BVIIRS encoder offset and gain will be set for Moon observation
21:50:05 Z M-bM-^@M-^S 21:56:05 Z M-BS-NPP will be pointing off-nadir, collected data may be impacted and not disseminated