Friday 16 January 2015 9.00am EDT
During a real-time pass on Jan 11 the ACIS Digital Processing Assembly Side-A (DPA-A) was detected in an unexpected powered-off state. Engineering assessment indicated behavior consistent with prior cases where the DPA powered-down. In each of those cases a fault-tree analysis concluded the event was due to a single event upset. The DPA was powered back on and the required software patches reloaded during a real-time pass on Jan 12. Scheduled observing resumed at 12:51am EST on Jan 13 with 99.0ks of science loss. Scheduled observations of 2MASS J06593158-0405 and 3C 120 were impacted by the DPA-A shut-down and will be rescheduled in future weeks. A real-time procedure was executed on Jan 13 to power on the A-side Solid State Recorder (SSR-A). This action enables the on-board recording of data should another Interface Unit reset occur. Preparations are complete for the winter 2015 eclipse season; the season contains seven eclipses and runs from Jan 16 to Feb 1. Real-time procedures were executed on Jan 15 to prepare for the first eclipse: one to activate SCS 29, one to dump and clear the EPS glitch counters, and one to set the short eclipse flag to "true". The schedule of targets for the next week is shown below |
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Radiation Belts Jan 19 M82 ACIS-S Jan 20 J235535.83-011444.1 ACIS-I ZwCl2341.1+0000 ACIS-I CXOUJ164043.5-46313 ACIS-I Jan 21 Abell3411 ACIS-I Radiation Belts Jan 22 CXOUJ164043.5-46313 ACIS-I Abell3411 ACIS-I Jan 23 CXOUJ164043.5-46313 ACIS-I Abell3411 ACIS-I CXOUJ164043.5-46313 ACIS-I Jan 24 Radiation Belts CXOUJ164043.5-46313 ACIS-I Jan 25 Abell3411 ACIS-I
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All spacecraft subsystems continued to support nominal operations.
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