To:sot_shift from: Dan Schwartz date: 05 Nov 01, 12:00noon EST Subject: SOT shift report 2001-11-05 M837 -------- See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or /proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Nov_05_2001_M837.txt. Shift M837. Start at 309:19:00 GMT = 02:00pm 05 Nov EST End 4:00pm 05 Nov SOT Lead DAS (Times will be given in GMT on day 309.) PLAN ---- Observing program was stopped automatically by RADMON trigger of SCS 107 at 308:17:37:06. We have uploaded NOV0501C to start at 2001:309:21:57:00.000 to get to a safe hold attitude. Next Comms: 309:1930 to 2030 310:0500 to 0600 310:1315 to 1415 310:2350 to 0150 311:0800 to 1000 311:1650 to 1850 312:0315 to 0415 312:1310 to 1410 312:2000 to 2100 313:0500 to 0600 Orbital events: 2001:310:15:55:48.552 311 EAPOGEE ORBIT APOGEE 2001:311:17:08:04.685 311 EE1RADZ0 ELECTRON1 RADIATION ENTRY0 2001:311:23:40:55.031 311 EPERIGEE ORBIT PERIGEE 2001:312:04:18:04.685 312 XE1RADZ0 ELECTRON1 RADIATION EXIT0 2001:313:07:24:21.071 312 EAPOGEE ORBIT APOGEE 2001:314:14:13:25.118 312 EE1RADZ0 ELECTRON1 RADIATION ENTRY0 2001:314:15:08:54.429 312 EPERIGEE ORBIT PERIGEE EVENTS ------ Status at LOS, 309:11:58:59, was as follows: PCAD MODE = NPNT CONTROL LAW FLAG = NPNT Stars: = 5 FIDS = 0 RA = 97.713 deg Dec = -28.597 deg ROLL = 59.496 deg Format = 2 OBSID = 2010 (held from SCS 107) SIM FA = -467 SIM TSC = -99616 (HRC-S) HETG = OUT (79.84 deg) LETG = OUT (77.96 deg) HRC-I HV is ON EPHIN Geom = smal E1300 = 1374.0 LT 10.0 (RADMON P4GM = 6200.5 LT 300. Triggered) P41GM = 117.2 LT 8.47 A-leak = 1.0200 mu-a B-leak = 0.4000 mu-a Ascending through 47655 km. Status at AOS, 309:19:32:52, was as follows: PCAD MODE = NPNT CONTROL LAW FLAG = NPNT Stars: = 5 FIDS = 0 RA = 97.716 deg Dec = -28.598 deg ROLL = 59.498 deg Format = 2 OBSID = 2010 (held from SCS 107) SIM FA = -467 SIM TSC = -99616 (HRC-S) HETG = OUT (79.46 deg) LETG = OUT (77.96 deg) HRC-I HV is ON EPHIN Geom = smal E1300 = 1081.3 LT 10.0 (RADMON has P4GM = 3111.1 LT 300. Triggered) P41GM = 104.3 LT 8.47 A-leak = 1.0200 mu-a B-leak = 0.4000 mu-a Ascending through 94643 km. ACIS focal plane temperature -119.9. 2029: LOS. Status essentially unchanged. Although we are out of the radiation belts, EPHIN rates are increasing: E1300 = 1739.8 LT 10.0 (RADMON has P4GM = 5181.6 LT 300. Triggered) P41GM = 182.9 LT 8.47 Ascending through 99118 km. ACIS focal plane temperature -119.9. NOTES/ISSUES/PROBLEMS ACIS has reported another T-plane latchup event. It occurred on the last observation before SCS107 ran. This was OBSID 2010, which has to be repeated anyway due to the SCS 107. The observations before 2010 look fine. ACIS is treating this, along with the Oct 29, 2001 and Jun 26, 2000 events as an unresolved anomaly. We anticipate possible diagnostic CAP's to dump information from ACIS on-board software, and/or to reload on-board software. Potential work-arounds for this situation were discussed at last Thursday's ACIS ops team meeting, and could be implemented on short notice if we can assure ourselves there is not an underlying hardware problem which would contra-indicate. From current GOES proton rates, we would estimate P4GM and P41GM are factors of 10 to 30 above the EPHIN RADMON trigger levels, whereas we will require them to be no more than 1/3 the trigger level before resuming the load. Observed rates are 20 to 50 times above trigger levels. We are working to a replan which would resume with OBSID 1624 when we exit perigee at about 312:09, but in view of the strength of the current storm, we are pessimistic that it will abate by then. Additional comm has been obtained so that we can check the EPHIN rates after perigee passage #311, before committing to activate the loads. ------------------------------------------------------- Dan Schwartz, MS #3 das@head-cfa.harvard.edu phone: (617)495-7232 FAX: (617)495-7356 cell phone: (617)512-5627 pager: 877-693-7198 PIN 693-7198 or e-mail 6937198@archwireless.net -------------------------------------------------------