SOT Shift Report Shift L94 Duration: 25 Oct 1999 07:00 EDT - 25 Oct 1999 12:00 EDT 25 Oct 1999 11:00 GMT - 25 Oct 1999 16:00 GMT SOT Lead: Tom Aldcroft Spacecraft/Aspect: FOT/Science Liason: HRC: ACIS: ======================================== Plan ---- Continue running load P23 Events ------ Day 298 10:54 AOS on DSS-54 11:33 LOS Notes/Issues/Problems --------------------- - Ed Bogen checked ACIS telemetry at ~13:00 GMT and said all was well. - HRC EGSE showed no red-limits and just the usual yellow flags - At the 9am status meeting Roger reported that the CAP to change the SIM position (Obsid 678, Rapid Burster) was rejected due to a number of complications which the change would entail. Among these were: requirement of a new ObsId, and concerns about command contention, loss of fid lights, and subsequent SIM translation timing issues. - Since the last safe mode, there have been at least 4 cases of a large one-shot attitude update ( > 80 arcsec). Jeff Shirer is working to prepare a report on details of each of these large updates, as well as a summary of all recent one-shot updates to try to understand what is happening. In the meantime he has supplied us with the approximate times of the large update cases so we can investigate in parallel. Potential causes include: changing gyro scale factor and misalignment matrix; uncompensated bias; stellar aberration; and errors in OFLS star positions. - CXCDS ops reported on quick-look status of several observations: - Obsid 105 and 532 look nominal - Obsid 1450 has only 185 seconds of exposure, apparently due to problems in data dumps. If the data are really unrecoverable this observation likely has to be rescheduled. - In Obsid 521, there is a bright source well off-axis, near the chip edge. Presumably this was the intent of the offset specified in the OR. Snapshot -------- UTC 1999:298:14:59:00 (Mon Oct 25) OBT 1999:298:11:33:30 CTUVCDU 9503743 FMT1_NORM OBC s/w NRML OBC Errs 0 OBT 57238410.94 ONLVCDU 9503736 OBSID 1406 EPState SUN SIM TTpos -50505 HETG Angle 81.0 PCADMODE NPNT RA 278.367 Bus V 30.71 SIM FApos -715 LETG Angle 81.3 PCONTROL NPNT Dec -10.552 Bus I 30.01 AOFSTAR GUID Roll 278.721 ACA Object FFFSSSSS Dither ENAB HRC-I HV ON ACA ImFunc TTTTTTTN Dith Yang -1.14 Yaw Rate 0.20 HRC-S HV OFF ACA CCD Temp -10.4 Dith Zang 12.82 Pitch Rate 0.13 OBSMode OBSV ACA Int Time 1.698 Roll Rate 0.02 Door OP ACT AOACSTAT OK FSS SunAlfa SUN Door CL UNAC FSS Alfa -0.23 Batt 1 SOC 100.00% Avg HRMA Temp 70.58 FSS Beta 22.26 Batt 2 SOC 100.00% Avg OBA Temp 50.81 SA Resolv 67.81 Batt 3 SOC 100.00% ACIS Stat7-0 64 OBA Tavg Fault NFLT SA Sun Pres ILLM Cold Rad -120.7 OBA Trng Fault NFLT Warm Rad -82.0 HRMA power 99.30 OBA power 102.90 EPHIN Geom LARG INT cnt 114 Roll Mom. -4.877 P41GM cnt 0 Pitch Mom. -2.031 A-Leak 0.2000 Yaw Mom. 4.155 B-Leak 0.0320