11/10/04 NSM/radiation telecon ------------------------------ At ~2004:315:16:41 UT a high EPHIN P4GM flux caused SCS-107 to run. During the first SIM translation within SCS-107, the stars were lost as typically occurs but were not re-acquired. Because the spacecraft attitude was such that the sun was outside the fine sun-sensor field-of-view, rather than locking onto bright stars Chandra transitioned to normal-sun mode. This evening the procedure was run to recover from normal-sun mode to normal-point mode (tracking stars at a known attitude). Commanding for the recovery started at ~2004:316:01:20 UT and the procedure was completed by ~02:50. The procedure ran nominally. A maneuver only schedule (NOV1104B) to take Chandra to a thermally preferable attitude has been uplinked. The tentative plan is for a resumption of the science mission at radiation zone exit on day 317 but this will depend on the radiation environment. Nov 12, SOT Shift Report ------------------------- At ~2004:315:16:41 UT a high EPHIN P4GM flux caused SCS-107 to run. During the first SIM translation within SCS-107, the stars were lost as typically occurs but were not re-acquired. Because the spacecraft attitude was such that the sun was outside the fine sun-sensor field-of-view, rather than locking onto bright stars Chandra transitioned to normal-sun mode. Recovery from NSM Wednesday evening (Nov 10): This evening the procedure was run to recover from normal-sun mode to normal-point mode (tracking stars at a known attitude). Commanding for the recovery started at ~2004:316:01:20 UT and the procedure was completed by ~02:50. The procedure ran nominally. A maneuver only schedule (NOV1104B) to take Chandra to a thermally preferable attitude was uplinked. The maneuver completed at 316:0457. Replan load NOV1204C: A replan load (NOV1204C) was prepared and uplinked at the 317:0345-0445 COMM. The first segment of that load contained two maneuvers to achieve better attitude. These were completed at 317:0600. The first science observation of the load was to begin at 317:1400 (in a different load segment). Radiation levels are down from yesterday, soft protons at a flux of about 1000. However, there was an X2.5 flare last night and solar activity is moderate to high. If we decide to start the load the first observation will begin at 315:1709 UT.