SOT Shift Report Shift M497 Duration: 30 Nov 2000 12:30 EST - 30 Nov 2000 14:30 EST 30 Nov 2000 17:30 GMT - 30 Nov 2000 19:30 GMT SOT Lead: Tom Aldcroft Spacecraft/Aspect: FOT/Science Liason: Eric Martin HRC: ACIS: ======================================== Plan ---- - Continue with NOV2800a load 01987 VELA PULSAR 2000:335:15:30:17.120 19.2 ACIS-S NONE 02138 1136-135 2000:335:21:18:17.120 9.6 ACIS-S NONE I1925 CAL-ER 2000:336:00:29:55.060 0.0 -- -- 01925 4U2129+47 2000:336:01:01:20.899 36.5 ACIS-S NONE - Run CAP 682 to re-initialize thruster command processing - Run CAP 447 to dump the PEA1 patch table memory Events ------ 18:00 AOS on DSS-24 18:21 CAP 447 run 18:30 CAP 682 run 19:00 LOS Notes/Issues/Problems --------------------- - CAP 682 was successful, and the OFP thruster command processing was re-initialized - CAP 447 was run to dump the portion of ACA memory which contains the patch vector table. The purpose was to verify that the Fid Rate limit patch is installed and running. The memory dump matched the expected values and we conclude that the patch is running. For the fid light loss on NOV1400 (obsid 2121), I examined the image and centroid data and discovered that just prior to loss of track, the OBC reported a fid light centroid which was shifted ~10 pixels from the prior position! Eric and I reviewed the actual patch code and PEA algorithms and agreed that, even with the patch in place, we would expect the loss of track in this situation. The real mystery now is how the centroid could be shifted so far. One possibility is a large cosmic ray covering several pixels, including the background pixels. More investigation is needed: characterizing the true loss rate (since it is largely anecdotal at this point), and finding a smoking-gun example where the pixel data capture the cosmic ray which dragged off the centroid. - Radiation is reasonably low: EPHIN rates (cts/cm^2-s-sr) OBSERVED RADMON limit ------------ ------------- E1300 (electrons, 2.64 - 6.18 MeV): 0.4 10.0 P4GM (protons, 5.0 - 8.3 MeV): 12.4 300.0 P41GM (protons, 41 - 53 MeV): 0.0 8.47 - ACIS FP temperature: -119.9 C Snapshot -------- UTC 2000:335:18:59:02 (Nov30) f_ACE 1.18e+03 F_ACE 4.33e+07 Kp 1.7 R km 138280D OBT 2000:335:18:58:08 CTUVCDU 12787839 OBC s/w NRML FMT2_NORM CPEstat NORM OBT 91997888.35 ONLVCDU 12787824 OBC Errs 0 OBSID 1987 EPState SUN SIM TTpos 75623 HETG Angle 79.84 PCADMODE NPNT RA 128.859 Bus V 29.93 SIM FApos -467 LETG Angle 78.34 PCONTROL NPNT Dec -45.182 Bus I 34.31 AOFSTAR GUID Roll 55.074 ACA Object FFFSSSSS Dither ENAB HRC-I HV OFF ACA ImFunc TTTTTTTT Dith Yang -1.23 Yaw Rate 0.27 HRC-S HV ON ACA CCD Temp -10.4 Dith Zang 1.88 Pitch Rate 0.02 OBSMode NEXT ACA Int Time 1.698 Roll Rate -0.10 Door OP UNAC AOACSTAT OK FSS SunBeta SUN Door CL UNAC FSS Alfa -0.46 Batt 1 SOC 100.00% Avg HRMA Temp 70.58 FSS Beta -2.95 Batt 2 SOC 100.00% ACIS Stat7-0 65 Avg OBA Temp 50.97 SA Resolv 92.69 Batt 3 SOC 100.00% Cold Rad -127.9 OBA Tavg Fault NFLT SA Sun Pres ILLM Warm Rad -82.0 OBA Trng Fault NFLT +Y SA Amps 16.44 RADMON ENAB HRMA power 130.80 SCS 128 ACT -Y SA Amps 17.43 EPHIN Geom LARG OBA power 109.30 SCS 129 ACT +Y SA Temp 115.85 E150 1084.9 SCS 130 ACT -Y SA Temp 115.85 E300 22.7 Roll Mom. 17.557 E1300 0.4 Pitch Mom. -9.265 UpL Cmd Acc 7131 EPH A-Leak 0.7520 P4GM 12.4 Yaw Mom. 3.430 Cmd Rej A 194 EPH B-Leak 0.1400 P41GM 0.0 Current Data: UTC 2000:335:21:09:01 (Nov30) f_ACE 1.25e+03 F_ACE 5.24e+07 Kp 1.3 R km 135024D Currently scheduled FPSI, OTG : ACIS-S NONE Costello Kp : 1.33 ACE EPAM P3 Proton Flux (p/cm^2-s-sr-MeV) : 1.25e+03 Orbit Start Time : 2000:334:04:49:00 Geocentric Distance (km), Orbit Leg : 135024 D CRM Region : 1 (Solar_Wind) External Proton Flux (p/cm^2-s-sr-MeV) : 1.25e+03 Attenuated Proton Flux (p/cm^2-s-sr-MeV) : 1.25e+03 External Proton Orbital Fluence (p/cm^2-sr-MeV) : 3.46e+08 Attenuated Proton Orbital Fluence (p/cm^2-sr-MeV) : 7.16e+07