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Friday 10 October 2008 7.00am EDT
| During the last week loads were replanned three times to include
sources 3C66A, AXP 1E1547.0-5408 and 1ES0120+340 that were accepted as
fast turn-around targets of opportunity (TOO) on Oct 1, 3 and 6
respectively. Observations of H 2356-309, AEGIS-3, SDSS J0148+0001, BP
Psc, GRB 080913, and BHR71-MM were affected and will be rescheduled in
later loads.
On Oct 5 the ACIS instrument experienced an unexpected Back End Processor (BEP) reboot. The event resulted in a reversion to the pre-launch version of the ACIS flight software. A real-time procedure was run on Oct 5 to warm-boot ACIS to reload the recently up-linked patches, so as to allow the scheduled observations to proceed. Since the cause of the reboot was not immediately known and the new software could not be completely exonerated, the conservative decision was subsequently made to re-load version 33 of the ACIS software rather than continue with the new version (44). The re-load and reboot occurred on Oct 6. ACIS has operated nominally since the reversion to version 33 of the flight software. The ACIS team has begun a fault tree analysis and to attempt to recreate the event on the ACIS engineering unit. The schedule of targets for the next week is shown below. |
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Radiation Belts Oct 12 EXO0748-676 ACIS-S M31 ACIS-I Oct 13 NGC24 ACIS-S XTEJ1701-462 ACIS-S CarinaEastPtg4 ACIS-I Oct 14 Radiation Belts Oct 15 EXO0748-676 ACIS-S CarinaEastPtg4 ACIS-I EtaCar ACIS-S/HETG MACSJ0025.4-1222 ACIS-I Oct 16 MACS1621 ACIS-I Oct 17 Radiation Belts MACS1621 ACIS-I Oct 18 1E1547.0-5408 ACIS-S MACSJ0025.4-1222 ACIS-I IGRJ17204-3554 ACIS-I Oct 19 EtaCar ACIS-S/HETG 1E1547.0-5408 ACIS-S Oct 20
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All spacecraft subsystems continued to support nominal operations.
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Revised: July 08, 2022