Aug 2/3 1999 A12 Shift SOT Lead Bill Podgorski SpcCraft/Aspect Rob Cameron FOT/Sci liason Eric Martin HRC Gerry Austin/Adrian Roy ACIS Royce Buehler (Times will be given in GMT on day 214-15. not precise.) PLAN HRC-I Checkout activities finished on B11 shift (early) Continue vacuum monitor monitoring till earth scan. Continue ACIS-S Event Histogram - OBSID 62986 Turn vacuum monitor off before earth scan ATS (SOP 0X004) configures HRC and ACIS for radiation zone passage Prepare to execute CAP 98 to prepare HRC and ACIS for radiation zone passage if above ATS fails Execute CAP 70 Step 1 to disable RADMON monitoring thru perigee passage Enter radiation zone at 215:07:08 Perform SSR dump Initiate Earth scan 18a - at 136 deg pitch Perigee passage at 215:10:40 EVENTS TIME OBSID -------------- --------- ----- Start shift (9:19pm EDT 02 Aug 1999) 215:00:45 62986 Continue monitoring ACA fidlites ongo Continue ACIS-S Event Histogram ongo 62986 Go into format 4 (by mistake) 215:01:20 DSN handover Madrid to Goldstone 215:02:05 Vacuum monitor OFF 215:04:52 Initiate SSR dump 215:06:05 Go back to format 2 215:06:20(approx) Complete SSR dump 215:05:40 ACIS stops data collection 215:06:50 Rad safing ATS runs to safe ACIS 215:07:08 Rad safing ATS runs to safe HRC 215:07:17 Run CAP70 step 1 run to disable RADMON 215:07:21 Loss of telemetry from Goldstone to Cambridge 215:07:46 Goddard and JPL (good lock on spacecraft) Regain telemetry 215:08:10 Telemetry ratty Start maneuvers for earth scan 215:08:30(approx) Load earth scan OBSID 215:09:03 62480 Earth scan starts 215:09:05 Lost telemetry due to switch of subcarrier mode 215:09:20 Telemetry recovered 215:09:30 LGA swap (short telemetry loss) 215:09:59 Goldstone LOS 215:10:08 Perigee 215:10:40 Diego Garcia AOS 215:10:50 Lost two FID lights in perigee pass Execute CAP 129 Option 1 to recover FID Lights Reset FID lites 215:10:58 Full field search for 4 lites 215:11:00 Command monitor windows 215:11:01 Command 8 x 8 windows 215:11:02 (SAP 6A025) Diego Garcia LOS 215:11:30 Madrid AOS End shift (9:19am EDT 03 Aug) 215:12:45 62480 NOTES/ISSUES/PROBLEMS --------------------- Format 4 was commanded at approx 215:01:20. This happened during shift change and was not caught until 215:06:20 thus causing loss of 5 hours of ACIS histogram data. SOT was asked to consider implicationsof no further LAE burns for Chandra mission (the question about mission implications comes from MSFC). We used the SPENVIS trapped particle analysis results from Y. Butt., using AP-8MAX model, in comparison to AL Solar flare fluence, for protons >30 MeV. This shows that the intregrated radiation dosage for a 5 year mission, with perigee at 3480 km (no orbit evolution) is comparable to an AL flare (flight design provides for 2). We therefore recommended against staying at the current perigee altitude. A quick check of ACA telemetry before the PEA reset showed no RAM failure address in diagnostic telemetry, indicating that the anomolous ACA behavior was not caused by a RAM upset. ACA lost two FID lights (slots 5 and 6) in perigee pass (9th and 7.4 mag objects, faintest and third faintest). Recovered within 11 minutes of detection - A RECORD. Comm gap between Diego Garcia (215:11:30) and Madrid (215:13:15) at end of shift OPSID = 62480 at end of shift (earth scan).