To:sot_shift from: Dan Schwartz date: 08 Sep 05, 12:00noon EDT Subject: SOT shift report 2005-09-08 L2240 -------- See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or /proj/web-cxc/htdocs/acis/SOT_reports/Sep_08_2005_L2240.txt. Shift L2240. Start at 251:13:00 GMT = 08:00am 08 Sep EDT End 10:00am 08 Sep SOT Lead DAS (Times will be given in GMT on day 251.) PLAN ---- Loads have stopped due to autonomous SCS 107 at 251:01:57:56 due to high E1300 rates. Maneuver only load SEP0805A needs to be uplinked at the 1400GMT pass to prevent a high momentum condition. Earliest resumption of science observing could be at 252:19:28 following the next perigee passage. Next Comms: 251:2040 to 2240 252:0345 to 0445 252:1410 to 1610 252:2340 to 0140 253:0345 to 0445 253:1100 to 1200 253:1720 to 1820 253:2120 to 2320 254:0345 to 0445 254:1040 to 1240 Orbital events: 251:03:37:25.953 841 EAPOGEE ORBIT APOGEE 252:11:21:03.392 841 EPERIGEE ORBIT PERIGEE 253:19:04:37.055 842 EAPOGEE ORBIT APOGEE 255:02:48:12.968 842 EPERIGEE ORBIT PERIGEE 256:10:32:11.761 843 EAPOGEE ORBIT APOGEE 257:18:15:16.544 843 EPERIGEE ORBIT PERIGEE 259:02:00:03.510 844 EAPOGEE ORBIT APOGEE 260:09:43:05.744 844 EPERIGEE ORBIT PERIGEE EVENTS ------ Status at LOS, 251:04:38, was as follows: PCAD MODE = NPNT CONTROL LAW FLAG = NPNT Stars: = 5 FIDS = 0 RA = 34.164 deg Dec = -17.762 deg ROLL = 81.912 deg Format = 2 OBSID = 5760 cl0216-1747 position SIM FA = -535 SIM TSC = -99615 (HRC-S) DITHER = ENAB HETG = OUT (79.09 deg) LETG = OUT (77.59 deg) HRC-S HV is ON EPHIN Geom = SMAL E150 = 7146.3 E300 = 243.0 E1300 = 24.0 LT 10.0 (RADMON P4GM = 29.0 LT 300. Disabled) P41GM = 0.1 LT 8.47 A-leak = 1.0200 mu-a B-leak = 1.0200 mu-a Descending through 126423 km. ACIS focal plane temperature -119.7 degC. EPH temp 97.37 degF SEP0905A maneuver load products have been approved and signed by the Flight Director. 14:04 AOS, status is essentially unchanged. Radiation levels are a little higher. EPHIN Geom = SMAL E150 = 14243.9 E300 = 473.9 E1300 = 55.0 LT 10.0 (RADMON P4GM = 38.7 LT 300. Disabled) P41GM = 0.3 LT 8.47 Descending through 116358 km. ACIS focal plane temperature -119.7 degC. EPH temp 96.12 degF NOTES/ISSUES/PROBLEMS From the 9am status meeting: Three supports over the last 24 hours, and one currently in callup. Had a problem commanding for the first six minutes of the DSS-66 pass. One segment of SEP0505C was uplinked, but will not run due to the SCS 107 trip. At the pass starting 03:40 GMT this morning it was noticed that SCS 107 had run. Triggered by E1300 at 01:57:36. SCS 107 ran nominally and gave all the expected errors. Our current position will violate momentum limits at 18:26 today, so we have built SEP0805A as a manuever only load. All reviews are in and approval is expected so it can be uplinked at the 1400GMT pass this morning. The start of the pass scheduled for 20:40 was moved forward to 18:40 as a backup in case we don't successfully uplink the maneuver load at the 1400 pass. EPHIN temperature at present attitude is 98 degF. Prediction had been below 96 deg, but this is within the known prediction accuracy and is accounted for by the margins used. Another LAE dome thermistor is showing signs of failure, similar to other previous failures. There are no operational impacts. We failed over to DB1, running DB2 as a backup. Generator maintenance is scheduled for next Friday. The 405 244 5060 conference numbers gave poor performance yesterday. They were noisy and cut speakers off. The provider was notified of the problem. Radiation Telecon Summary: Plan A for science restart is to pick up with obsid 6365 on perigee egress, at 19:28 GMT tomorrow. Loads must be uplinked during the 1410 to 1610 GMT pass tomorrow morning. It is credible that we will just get a "glancing" blow from yesterday's flare with only a brief spike in soft protons, and that Plan A will be viable. However, we might get a more substantial proton increase and not be able to use Plan A. Increasing the likelihood of doing Plan A is the schedule which has only 19 ks of ACIS/NONE, followed by 68 ks of ACIS/HETG. There will be a radiation telecon following the 9am status meeting tomorrow. If we waive off Plan A, a Plan B would be to restart with obsid 5555, an ACIS/HETG observation starting at day 253:01:39. Such a load would have to be uplinked at the 2 hr pass starting at 23:40 tomorrow evening. Depending on conditions, other options may be discussed tomorrow. Quick look data: OBSID Target Time Comment ----- ------ -------------- ------- 6252 Cygnus A 250:05:07 ACIS-I NONE ok ------------------------------------------------------- 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 -------------------------------------------------------