Friday 7 April 2017 9.00am EDT
During the last week the Chandra observing schedule was interrupted by an entry to bright star hold (BSH) at 3:01 pm on Friday, Mar 31 due to the failure to acquire the commanded stars in the aspect camera at the end of a maneuver. The entry into BSH was nominal and an assessment of the telemetry indicated that all spacecraft hardware was performing nominally. The most-likely cause for failing to acquire stars is that an initial roll attitude and gyro-bias error resulted in a maneuver error that placed the commanded acquisition stars outside of their search boxes. Real-time procedures were executed on Mar 31 to recover from BSH. Loads for a replanned schedule were uplinked on Apr 1 with 105ks of science loss. Observations of SNR 0509-68.7, TWA 34, NGC 4848 and ArLac were impacted by the interruption and will be rescheduled. The schedule of targets for the next week is shown below and includes observations of M87, a Director's Discretionary Time Target of Opportunity approved on Feb 27 coordinated with NuStar and the Event Horizon Telescope, and observations of Sgr A* coordinated with the Event Horizon Telescope. |
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TWA 32 ACIS-S Apr 9 Radiation Belt Apr 10 SNR 0509-68.7 ACIS-S SgrA* ACIS-S Apr 11 Coma cluster ACIS-I M87 ACIS-S Apr 12 SgrA* ACIS-S Coma cluster ACIS-I J1247-3816 ACIS-S Radiation Belt Apr 13 Coma cluster ACIS-I M87 ACIS-S Apr 14 TWA 32 ACIS-S SNR 0509-68.7 ACIS-S J1247-3816 ACIS-S Apr 15 Radiation Belt Apr 16 NGC 4848 ACIS-S NGC 4356 ACIS-S SDSS1004+4112 ACIS-S
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All spacecraft subsystems continued to support nominal operations.
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