Apr_21_2001_L639.txt Shift M639 Start at 2001:111:21:00:00 GMT = 2001 Apr 21 5:00pm EDT End 2001 Apr 21 10:30pm EDT SOT shift report 2001-04-21 M639 See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or /proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Apr_21_2001_M639.txt SOT Lead Robert Cameron SOT SC/ACA FOT-SI HRC-SI ACIS-SI OTHER Plan: - Recovery from NSM to NPM using CAP 720 rev C and SOP 56005, and then resume science mission (see Notes 2 and 3). Resume science mission with load APR2201B load, which starts with ToO target SGR 1900+14. Seq # ObsID It Target start time SI Grat RA dec roll --------------------------------------------------------------------------------------------------- 500199 02458 00 SGR 1900+14 2001:112:04:58:00.000 20.0 ACIS-S NONE 286.8284 9.3127 104.38 600206 02072 00 NGC 4552 2001:112:11:32:24.381 55.0 ACIS-S NONE 188.9159 12.5773 221.18 700285 02453 00 3C 228 2001:113:03:17:04.381 10.8 ACIS-S NONE 147.5343 14.3517 249.94 ORBITAL EVENTS: 2001:111:00:02:38.816 235 EPERIGEE ORBIT PERIGEE 2001:112:07:46:44.095 236 EAPOGEE ORBIT APOGEE 2001:113:15:29:49.782 236 EPERIGEE ORBIT PERIGEE 2001:114:23:14:32.274 237 EAPOGEE ORBIT APOGEE 2001:116:06:58:19.755 237 EPERIGEE ORBIT PERIGEE 2001:117:14:43:01.976 238 EAPOGEE ORBIT APOGEE 2001:118:22:27:47.552 238 EPERIGEE ORBIT PERIGEE 2001:120:06:11:48.551 239 EAPOGEE ORBIT APOGEE 2001:121:13:56:47.734 239 EPERIGEE ORBIT PERIGEE 2001:122:21:40:04.571 240 EAPOGEE ORBIT APOGEE 2001:124:05:24:14.175 240 EPERIGEE ORBIT PERIGEE 2001:125:13:07:36.076 241 EAPOGEE ORBIT APOGEE 2001:126:20:50:42.256 241 EPERIGEE ORBIT PERIGEE 2001:128:04:34:46.596 242 EAPOGEE ORBIT APOGEE 2001:129:12:18:01.609 242 EPERIGEE ORBIT PERIGEE 2001:130:20:02:04.274 243 EAPOGEE ORBIT APOGEE EVENTS DONE OBSID -------------- ---- ----- Start Shift 111:2100 AOS DSS-54 (Madrid 34m) 111:2130 61660 End of shift 112:0230 LOS DSS-54 (Madrid 34m) 112:0530 NOTES/ISSUES/PROBLEMS --------------------- 1) Status at 111/2142, before recovery: UTC 2001:111:21:42:07 (Apr21) f_ACE 1.43e+02 F_CRM 0.00e+00 Kp 1.0 R km 130352A OBT 2001:111:21:41:43 CTUVCDU 10372735 OBC s/w NRML FMT2_SSR CPEstat NORM OBT 104276503.20 ONLVCDU 10372720 OBC Errs 0 OBSID 61660 EPState SUN SIM TTpos -99616 HETG Angle 79.84 PCADMODE NSUN RA 298.617 Bus V 30.55 SIM FApos -467 LETG Angle 78.34 PCONTROL SPNT Dec 2.460 Bus I 32.54 AOFSTAR GUID Roll 97.423 ACA Object SSSSSSSS Dither ENAB HRC-I HV OFF ACA ImFunc NNNNNNNN Dith Yang 4.25 Yaw Rate 3.21 HRC-S HV ON ACA CCD Temp -10.4 Dith Zang 1.08 Pitch Rate -2.48 OBSMode NEXT ACA Int Time 0.705 Roll Rate -7.91 Door OP UNAC AOACSTAT OK FSS SunBeta SUN Door CL UNAC FSS Alfa -0.08 Batt 1 SOC 100.00% Avg HRMA Temp 70.61 FSS Beta -0.27 Batt 2 SOC 100.00% ACIS Stat7-0 67 Avg OBA Temp 51.13 SA Resolv 90.15 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 15.66 RadMon DISA HRMA power 91.30 SCS 128 INAC -Y SA Amps 16.44 EPHIN Geom LARG OBA power 91.40 SCS 129 INAC +Y SA Temp 110.51 E150 99.0 SCS 130 INAC -Y SA Temp 110.82 E300 2.4 Roll Mom. 3.761 SCS 107 DISA E1300 0.1 Pitch Mom. 6.402 UpL Cmd Acc 19547 EPH A-Leak 1.0200 P4GM 1.0 Yaw Mom. 2.939 Cmd Rej A 155 EPH B-Leak 0.2480 P41GM 0.0 Current Data: UTC 2001:111:22:03:03 (Apr21) f_ACE 0.00e+00 F_CRM 0.00e+00 Kp 1.0 R km 131051A Currently scheduled FPSI, OTG : HRC-S NONE Costello Kp : 1.00 ACE EPAM P3 Proton Flux (p/cm^2-s-sr-MeV) : 1.13e+02 Orbit Start Time : 2001:111:00:09:02 Geocentric Distance (km), Orbit Leg : 130919 A CRM Region : 3 (Magnetosphere) External Proton Flux (p/cm^2-s-sr-MeV) : 1.27062000000e+03 Attenuated Proton Flux (p/cm^2-s-sr-MeV) : 0.00000000000e+00 External Proton Orbital Fluence (p/cm^2-sr-MeV) : 2.11485128100e+08 Attenuated Proton Orbital Fluence (p/cm^2-sr-MeV) : 0.00000000000e+00 HRC SP PS = ON Steps 43/54 IM PS = OFF Shield 1 HV = OFF Shield 2 HV = OFF Valid Event Rate 1 = 0 Valid Event Rate 2 = 0 Shield Event Rates = 0 ACIS FP Temp = -119.9 DEA Pwr = 31.4 DPA Pwr = 12.2 Science State = Science Idle Status at 112/0206, after NPM recovery: UTC 2001:112:02:07:18 (Apr22) f_ACE 7.03e+01 F_ACE 0.00e+00 Kp 2.3 R km 137291A OBT 2001:112:02:06:51 CTUVCDU 10434815 OBC s/w NRML FMT2_EPS CPEstat NORM OBT 104292411.21 ONLVCDU 10434800 OBC Errs 0 OBSID 61660 EPState SUN SIM TTpos -99616 HETG Angle 79.84 PCADMODE NPNT RA 298.130 Bus V 30.24 SIM FApos -467 LETG Angle 78.34 PCONTROL NPNT Dec 11.877 Bus I 36.35 AOFSTAR GUID Roll 102.265 ACA Object SSSSSSSS Dither DISA HRC-I HV OFF ACA ImFunc TTTTTTTT Dith Yang 0.00 Yaw Rate -0.13 HRC-S HV ON ACA CCD Temp -10.4 Dith Zang 0.00 Pitch Rate -0.00 OBSMode NEXT ACA Int Time 1.698 Roll Rate -0.08 Door OP UNAC AOACSTAT OK FSS SunBeta SUN Door CL UNAC FSS Alfa -0.35 Batt 1 SOC 100.00% Avg HRMA Temp 70.58 FSS Beta 0.53 Batt 2 SOC 100.00% ACIS Stat7-0 67 Avg OBA Temp 51.13 SA Resolv 89.30 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 17.62 RadMon DISA HRMA power 100.30 SCS 128 INAC -Y SA Amps 18.41 EPHIN Geom LARG OBA power 126.50 SCS 129 INAC +Y SA Temp 110.82 E150 38.7 SCS 130 INAC -Y SA Temp 111.12 E300 1.4 Roll Mom. 4.964 SCS 107 DISA E1300 0.1 Pitch Mom. 4.379 UpL Cmd Acc 19763 EPH A-Leak 1.0200 P4GM 0.4 Yaw Mom. 3.232 Cmd Rej A 222 EPH B-Leak 0.2480 P41GM 0.0 Current Data: UTC 2001:112:02:07:18 (Apr22) f_ACE 7.03e+01 F_ACE 0.00e+00 Kp 2.3 R km 137291A Currently scheduled FPSI, OTG : HRC-S NONE Costello Kp : 2.33 ACE EPAM P3 Proton Flux (p/cm^2-s-sr-MeV) : 7.03e+01 Orbit Start Time : 2001:111:00:09:02 Geocentric Distance (km), Orbit Leg : 137217 A CRM Region : 2 (Magnetosheath) External Proton Flux (p/cm^2-s-sr-MeV) : 9.58027000000e+02 Attenuated Proton Flux (p/cm^2-s-sr-MeV) : 0.00000000000e+00 External Proton Orbital Fluence (p/cm^2-sr-MeV) : 2.26972698554e+08 Attenuated Proton Orbital Fluence (p/cm^2-sr-MeV) : 0.00000000000e+00 2) Normal Sun Mode transition Date: Sat, 21 Apr 2001 00:43:06 -0400 (EDT) From: Roger Brissenden To: fot@head-cfa.harvard.edu, sot@head-cfa.harvard.edu Subject: Normal Sun Mode Transition At approximately 10:20pm on Friday Chandra was found to be in normal sun mode unexpectedly. The cause of the transition has been understood as a bright earth constraint violation and was related to the new load built for the TOO intercept on Friday evening. Telemetry indicates all systems are nominal and the OBC error log and VCDU counter are consistent with a nominal transition from normal pointing mode through bright star hold to normal sun mode. Full verification will be made using the dump data on Saturday morning. A recovery plan has been developed with the goal of recovering the fine attitude on Saturday evening during an extended pass from 5.30pm - 1.10am Sunday (DSN time has been confirmed). A CAP/procedure review is expected Saturday afternoon as is a load review for the new load. The fine attitude recovery is expected to take 3-4 hours. Review time annoucements will be made to sot-red-alert. The current plan is for the loads to resume with the TOO and the last of the three pool targets of the current orbit. cheers, Roger. 3) Normal Point Mode Recovery CAP 720 was modified to revision C during the recovery. The CAP calls SOP 56005 for fine attitude initialization. In SOP 56005, the initial attempt to recover to Normal Point Mode (NPM) and hold on bright stars failed because the AOBRTSUC (ACA Bright Star search successful) flag is required to show success to allow the NPM transition. But the flag showed failed after last night's failed bright star hold and Chandra returned to NSM. The CAP was revised to fully initialize the ACA processes in the OBC and then SOP 56005 ran successfully. 8 stars were found by the ACA in the full field search for bright star hold, and pattern matching by the OFLS took about 15 minutes to complete. In addition, the adjustment of the IRU bias towards manufacturer's data, was removed from CAP 720 rev C. 111/2150: start CAP 720. 111/2209: transition to NSM during SOP 56005, in CAP 720. 111/2347: start CAP 720 rev C. 112/0000: start SOP 56005 112/0006: acquire bright stars 112/0110: perform attitude update 112/0140: complete maneuver to starting attitude for APR2201 load 112/0150: end of SOP 56005, CAP 720 rev C. 4) Radiation: The Chandra radiation environment is quiet. ACE EPAM P3: 2 hr fluence is 5.6e5 vs. threshold 3.6e8. CRM-based orbital fluence is 0.0e0 vs. threshold 1.0e9. Chandra is in the magnetosheath.