To:sot_shift from: Dan Schwartz date: 05 Nov 99 , 12:00noon EST Subject: SOT shift report, Shift L105 -------- See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or /proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Nov_05_1999_L105.txt. Shift L105. Start at 309:13:00 GMT = 08:00am 05 Nov EST End 12:00 noon 05 Nov SOT Lead DAS (Times will be given in GMT on day 309. In general times are rough, not precise.) PLAN Continue running load p24c. OBSID 96 for GS 2000+25, 501 for A2390, and 1233 for G21.5-0.9. EVENTS Status at LOS, 309:06:09, was properly observing Mkn 421 with ACIS-S/HETG as follows: PCAD MODE = NPNT CONTROL LAW FLAG = NPNT Stars: = 5 FIDS = 3 RA = 166.116 deg DEC = 38.184 deg ROLL = 53.963 deg Format = 2 OBSID = 457 SIM FA = -467 SIM TSC = 74073 (ACIS-S) HETG = IN ( 7.1 deg) LETG = OUT (79.5 deg) HRC-S HV is ON EPHIN: A-Leak = 0.22000 mu-a B-Leak = 0.03600 mu-a 16:30 AOS Status at 309:16:46 PCAD MODE = NPNT CONTROL LAW FLAG = NPNT Stars: = 5 FIDS = 3 RA = 300.683 deg DEC = 25.248 deg ROLL = 288.127 deg Format = 2 OBSID = 96 SIM FA = -535 SIM TSC = 92903 (ACIS-I) HETG = OUT (80.6 deg) LETG = OUT (79.5 deg) HRC-S HV is ON EPHIN: A-Leak = 0.3240 mu-a B-Leak = 0.0520 mu-a 16:52 Start maneuver to A2390. Expect LOS at 18:00. Next Comm expected 310:03:55 to 04:40 NOTES/ISSUES/PROBLEMS Look ahead operations: ACIS needs an engineering test for the FEP 0 patch. This patch has been run through a small test suite on the engineering unit, and needs to be proven to work when the actual FEP0 problem occurs on the flight unit. The concept is to install it on ACIS when running in next in line mode. Day 313, next Tuesday, Nov 9, is the target time, during the 24 hour HRC-S/LETG observation of Capella starting at 313:13:47 GMT (8:13am EST). New baselined ACIS tables for this have been installed in the ODB. The patch will be removed prior to resuming ACIS guest observations. If successful, it will be developed further (e.g., to handle the CC mode) and verified, and later be installed with the standard patch list. Load and removal of this patch can be accomodated by currently scheduled comm passes. ACIS also needs to test a particular scheme for reducing the charge transfer inefficiency: the slow image frame to store, parallel transfer mode. We need a real-time comm at 315:22 to carry this out, using the CTI measurement time on exiting the radiation belts. The specific purpose of this test is to see if the flight chip behaves identically to a chip tested on the ground. (This ground chip has been damaged by protons, which increases its CTI, and the CTI then was improved by the slow image-to-store parallel transfer.) If so, further work will be done investigating the damaged chip on the ground to optimize the "slow-shift" parameters. A new 5 hour real time pass is requested to accomplish this -- as short as a 2 hour pass could be used. Notes from 9am status meeting: In response to yesterday's issue of flowover to solid-state recorder B potentially causing data loss during manual change back to A, an extra contact was obtained to reset the SSR pointers and prevent this situation. A note published by Chris Carignan shows that the average data loss in the B to A switch is 40 frames. He suggests that when the SSR nears filling the A side, that we increase the allowed CFC count by 200 (= 40 frames maximum). This looks reasonable to me, and I suggest a more complete review of the SOP for SSR playback and pointer reset to identify and evaluate other special cases. Dan Shropshire will schedule a meeting for Monday, Nov 8, to finalize the Leonid encounter plans. Lunar, partial eclipse is predicted for Monday, 312:20:23 to 20:41. We will have comm, expect no impact on operations. Need SOT coverage, MDF is scheduled. Quick look data notes: OBSID 3 on Trapezium, 1422 and 1457 on LMC X-1, 509 on IRAS 09104, and 419 on RX J0911.4+0551 all look okay. The presentation of the SN 1999em OBSID 763 seems unusual to me, with a large gap between the two ACIS-I chips, and the ACIS-S chips appearing to be elongated in the direction of the S array. Ken Glotfelty points out this is due to the subarray mode being use, start row=256, row count = 511. SOT area in the TST room has been reconfigured to spread out the terminals and increase the table space: This is much appreciated! ------------------------------------------------------- Dan Schwartz, MS #3 das@head-cfa.harvard.edu phone: (617)495-7232 FAX: (617)495-7356 cell phone: (617)512-5627 pager: 800-759-8352 PIN 1636502 or e-mail 1636502@skytel.com -------------------------------------------------------