Jan_17_2000_M178.txt Shift M178 Start at 2000:017:21:00:00 GMT = 2000 Jan 14 4:00pm EST End 2000 Jan 14 7:00pm EST See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or /proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Jan_17_2000_M178.txt SOT Lead Robert Cameron SOT SC/ACA FOT-SI HRC-SI ACIS-SI OTHER Plan: - Running load JAN1600 load: Obsid 00049 E0102-72.3 ACIS-I, NO OTG Obsid 00346 PICTOR A ACIS-S, NO OTG 2000:018:04:33:35.804 62 ORBIT APOGEE 2000:019:12:18:19.454 62 ORBIT PERIGEE 2000:020:20:03:04.736 63 ORBIT APOGEE 2000:022:03:48:38.461 63 ORBIT PERIGEE 2000:023:11:32:11.401 64 ORBIT APOGEE EVENTS DONE OBSID -------------- ---- ----- Start Shift 017:2100 AOS DSS-24 (Goldstone) 017:2315 49 Chandra status at AOS was nominal (see note 2) End of shift 018:0000 Obsid Change 018:0026 346 LOS DSS-24 018:0015 NOTES/ISSUES/PROBLEMS --------------------- 1) Chandra snapshots and ACE monitoring were not running, due to yet another problem with the computer drongo. SAO syshelp has been notified. 2) Chandra's state at AOS 017:2315 was: WAS EXPECTED PCAD MODE = NPNT NPNT CONTROL LAW FLAG = NPNT NPNT Stars: = 5 5 FIDS = 3 3 RA = 15.79179 deg 15.79179 DEC = -72.12287 deg -72.12286 ROLL = -96.07537 deg 263.92464 Format = 2 2 OBSID = 49 49 SIM FA = -535 -536 SIM TSC = 92903 92904 HETGA = 80.59 (OUT) OUT HETGB = 81.34 (OUT) OUT LETGA = 79.84 (OUT) OUT LETGB = 78.71 (OUT) OUT EPHIN A-leak = B-leak = HRC SP PS = ON IM PS = OFF SP Top Step = 43 Sp Bot Step = 54 Shield 1 HV = OFF Shield 2 HV = ON Shield 2 HV Step = 8 Valid Event Rate 1 = 0 Valid Event Rate 2 = 0 Shield 1 Event Rate = 0 Shield 2 Event Rate = 4300 ACIS FP Temp = -109.2 DEA Pwr = 52.2 DPA Pwr = 40.5 3) Notes from 4:00pm IRU meeting: Ron Sobchick reported on gyro (SKIRU) performance from another TRW satellite which has been operating for 5 years. 3 samples of gyro current jumps were obtained. For one of these samples, sun sensor data was available to allow gyro bias to be measured. Saw smaller bias change per milliamp of gyro motor current than Chandra gyro #2 in IRU-A. The effects of unmeasured gyro bias changes on Chandra maneuvers can be mitigated by increasing the search box sizes of acquisition stars after large maneuvers. FOT will investigate the OFLS capability to select acq stars with larger search box sizes. The FOT will trend gyro motor current and bias data on 1-hour averages, instead of 1 day averages. The SOT will look for increased errors in the post-facto aspect solution at the time of bias changes. After 3 quiet weeks, a gyro current jump and bias change was seen on gyro #2 on January 16. Jeff Shirer will look for disk space accessible to all interested parties, for the storage of data and results from the gyro investigation. 4) Quick Look data review: OBSID Target Time Comment ----- ------ -------------- ------- There was no new quick look data for review in this shift.