SOT/ACIS shift report 2002-01-28 L921 Start at 2002:028:14:05 GMT = 2002 Jan 28 9:05 pm EST End Jan 28 11:15 pm EST ACIS Joe DePasquale, Yousaf Butt, Paul Plucinsky, Shanil Virani, Royce Buehler, Catherine Grant, Bev LaMarr SOT Lead Bill Podgorski PLAN ---- Execute CAP 774 to perform a practice threshold-crossing plane latchup recovery. SUMMARY ------- Executed CAP 774 to familiarize the ACIS team with what TLM to expect in the event of an actual t-plane anomaly in which this CAP would be run. In step 4 of the CAP, in which ACIS is verifying TLM after the radiation flag has been set to HI, we noticed some unexpected TLM verifiers. We expected the DEA current to drop, and to see the status bit: 1STAT1ST toggle to 1 which means that science is idle. We also expected to see the following in software housekeeping: SWSTAT_SCI_INHIBIT_ON and SWSTAT_DEACCD_POWEROFF, as well as to see a termination code of 3 in SMTERM_RADMON. Of the expected TLM verifiers we did see the DEA current drop, we did see 1STAT1ST toggle to 1, we did see the two verifiers in software housekeeping, BUT we did not see SMTERM_RADMON, or a termination code of 3; the termination code that was actually telemetered was 15. In addition to the expected TLM we also received the following: FEP_IO_ERROR in Pmon, deaInterfaceErrorFlag=1, 5 DEA_BOARD_ERRORs - last one reporting the error code 0x00070004, and 2 SMRABORT (though Bev commented that 1 of these should have been expected). At this point, we paused in our execution of the CAP to verify that ACIS was indeed in the proper state and to consider the possible explanations for the different TLM verifiers. We confirmed that ACIS was in a "science inhibited state" due to the ACIS radiation flag being set HI and that the hardware was in the correct state. Royce suggested that the unexpected TLM verifiers could be explained by the TLM stream being saturated and the FEPs for the FI CCDs dropping frames as is expected in a normal CTI measurement. The ACIS flight SW will investigate this behavior through analysis of the code and tests on the engineering unit, if necessary, to fully explain the TLM verifiers. Given the confirmation of the correct state of the instrument and the plausible explanation for the TLM verifiers, we decided to proceed with the CAP. The remainder of the CAP was executed exactly as planned and all TLM verifiers were seen as expected. Detailed Timeline ----------------- GMT 028:14:05 AOS on DSS-54 028:14:15 Alttiude=82633 km and descending 028:14:19 FP Temp=-119.5 028:14:19 E150 30.00 E1300 0.04 P4GM 1.19 P41GM 0.00 028:14:30 OC/CC uplink loads 028:14:32 No problems, proceed with CAP 028:14:32 Execute script I_1_SET_RAD_FLAG.ssc (set rad flag hi) 028:14:35 Receive unexpected telemetry 028:14:40 Confirm science run has ended, decide to proceed 028:14:47 SCS 165 enabled and activated 028:14:48 Confirm that FEPs have powered down 028:14:49 Update OBSID: 62854 028:14:51 SCS 203 enabled and activated 028:14:52 Command ID seen for FEP power up 028:14:54 Confirm that FEPs have powered up 028:14:56 Execute script I_1_SET_RAD_FLAG.ssc (set rad flag lo) 028:14:57 Confirm restart of science run 028:15:00 SCS 207 enabled and activated 028:15:01 Command ID seen for dump system config 028:15:02 SCS 151 enabled and activated 028:15:02 Command ID seen for dump Huffman tables 028:15:03 OC/CC clears and disables SCS 165, 203, 207 and 151 028:15:10 Bias maps begin being telemetered! Bev confirms BIAS MAPs look OK 028:15:10 ACIS confirms normal science run 028:16:14 E150 35.71 E1300 0.02 P4GM 0.98 P41GM 0.00 028:16:15 LOS