Friday 10 March 2017 9.00am EST
During the last week the Chandra observing schedule was interrupted by an entry to normal sun mode (NSM) at 07:24 pm on Monday, Mar 6 due to the failure to acquire the commanded stars in the aspect camera at the end of a maneuver. The entry into NSM 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 a gyro-bias excursion occurred during the maneuver, which resulted in a maneuver error that placed the commanded acquisition stars outside of their search boxes. Real-time procedures were executed on Mar 7 to recover from NSM. Loads for a replanned schedule were uplinked on Mar 7 with 58ks of science loss. Observations of W831_0140, Coma Cluster and 4C63.20 were impacted by the interruption and will be rescheduled. The replanned observing schedule was again interrupted, this time by an entry to bright star hold (BSH) at 12:00 pm on Thursday, Mar 9 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 recovery procedure is planned for 10:00 am Mar 10. Impact to science observations cannot be assessed until new loads are uplinked, which is planned for the evening of Mar 10. The schedule of targets for the next week is shown below and includes observations of M51 coordinated with NuStar, an observation of WPVS 007 accepted as a Director's Discretionary Time Target of Opportunity on Feb 16 coordinated with HST, and an observations of Gaia16apd which was accepted as a Director's Discretionary Time Target of Opportunity on Jun 27. |
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Comacluster ACIS-I Mar 13 SNR1987A HRC-S /LETG PG1407+265 ACIS-S Mar 14 Radiation Belt Mar 15 Comacluster ACIS-I SNR1987A HRC-S /LETG WPVS007 ACIS-S Mar 16 Comacluster ACIS-I M51 ACIS-I Radiation Belt Mar 17 Comacluster ACIS-I E0102-72 ACIS-I Mar 18 E0102-72 ACIS-S NGC6015 ACIS-S Mar 19 Comacluster ACIS-I Gaia16apd ACIS-S IGRJ03599+5043 ACIS-I Radiation Belt
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All spacecraft subsystems continued to support nominal operations.
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