See https://cxc.harvard.edu/mta/SOT_reports/sot-shift.html Shift L8610. Start at 047:13:52 GMT PLAN ---- Plan for next recovery attempt. NOTES/ISSUES/PROBLEMS --------------------- From the 9am status meeting: 3 Supports Completed in the last 24 hours (Total time: 11.4 hours) 4 SSR dumps CAP's / Procedures Run: CAP # | Time | Title / Description / Notes [1681](/occweb/web/webapps/ifot/ifot.php?r=flightops&t=properties&format=sheet&id=867833) | 046/1945z | Post Safe Mode Recovery Cleanup On 13 Feb 2023 (day 2023:044) at approximately 17:41 UTC the Chandra observatory transitioned to Safe Mode. Investigations are complete as to the cause of the Sun Position Monitor trip that initiated the Safe Mode transition. Recovery to the primary-side equipment has been completed. Prior to completing the NSM recovery and returning to science mission activities, a number of clean-up actions are needed. This CAP is to be used to accomplish those clean-up tasks. [1677](/occweb/web/webapps/ifot/ifot.php?r=flightops&t=properties&format=sheet&id=867834) | 046/2001z | ET Offset Patch Uplink PR-555 Update the K constant KP.ET_Offset for the correct ephemeris time. [1685](/occweb/web/webapps/ifot/ifot.php?r=flightops&t=properties&format=sheet&id=867836) | 046/2032z | ACA Image Adjustment Because of increased temperatures on Chandra, nominal/default Aspect Camera operations may need some adjustment or improvement. During recovery from certain safing actions, high CCD temperatures may result in hot pixels, rather than stars, being tracked in particular ACA images. If these image data are used by the on-board Kalman filter for attitude control, attitude updates will be degraded. In addition, the usual Full Field Search command gives a 4x4 image readout in telemetry. While 6x6 or 8x8 image data will not be used for on-board control in Normal Sun mode, they may be useful on the ground to improve attitude determination. [1683A](/occweb/web/webapps/ifot/ifot.php?r=flightops&t=properties&format=sheet&id=867838) | 047/0223z | 2023:047 Ground Commanded Momentum Unload This CAP will be used to dump excess momentum that accrued during the 2023:044 Safe Mode Recovery activities. It will conduct a planned real-time momentum unload to [0, 0, 0] ft-lbf-sec while in NSM and blocking thruster A1 and A2. [1529A(2)](/occweb/web/webapps/ifot/ifot.php?r=flightops&t=properties&format=sheet&id=867839) | 047/0327z | Attitude Adjustment Using NSM Yaw Bias On 21 Oct 2022 the Chandra observatory transitioned to Safe Mode. The transition was nominal. Upon completing Safe Mode recovery, the spacecraft was in Normal Sun Mode, as expected, however the star field in the Aspect Camera field of view was too poor for NSM recovery. This condition (i.e., the inability to acquire stars) would prevent moving forward with recovery from Normal Sun Mode. As a result, by repeatedly applying a short-duration yaw bias while in NSM, the occultation caused by the Earth could be removed. This CAP will be used to set the Normal Sun Mode yaw bias to a non-zero value for a short time interval. [1682](/occweb/web/webapps/ifot/ifot.php?r=flightops&t=properties&format=sheet&id=867840) | 047/0402z | Bright Star Hold/Normal Sun Mode Recovery On 13 Feb 2023 (day 2023:044) at approximately 17:41 UTC the Chandra observatory transitioned to Safe Mode. Investigations are complete as to the cause of the Sun Position Monitor trip that initiated the Safe Mode transition. Recovery to the primary-side equipment has been completed. Completing NSM recovery is needed to return to science mission activities. This CAP will use steps in SOP_SAFE_NSM_BSH_RECOVERY to perform recovery. Radiation: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on day one (16 Feb) and expected to be low with a chance for M-class flares on days two and three (17 Feb, 18 Feb). Still just keeping an eye on active region 3226 but otherwise, space weather is quiet. MP: Engaged in recovery efforts. ENG: Spacecraft has re-entered safe mode. GOT: No issues. Quick look data: ---------------- OBSID Target Instr Grat ----- ------ ----- ---- None Next Comms: ----------- Support (GMT) BOT EOT Station Site Track time (local) --------------- ---- ---- --------- --------- ------------------------- 047/1620-1820 1720 1805 DSS-26 GOLDSTONE 1220-1305 EST, Thu 16 Feb 048/0205-0620 0305 0605 DSS-65 MADRID 2205-0105 EST, Thu 16 Feb 048/1050-1305 1150 1250 DSS-26 GOLDSTONE 0650-0750 EST, Fri 17 Feb 048/1940-2155 2040 2140 DSS-26 GOLDSTONE 1540-1640 EST, Fri 17 Feb SNAPSHOT summary: ----------------- UTC 2023:047:12:21:01 (Feb16) f_ACE 2.41e+02 F_CRM 0.00e+00 Kp 4.3 R km 152575A OBT 2023:047:12:18:02 CTUVCDU 66559 OBC s/w SAFE FMT5_NORM CPEstat SAFE OBT 792937082.09 ONLVCDU 797304 OBC Errs 0 OBSID 0 EPState SUN SIM TTpos -99616 HETG Angle 77.96 PCADMODE STBY RA 242.571 Bus V 27.11 SIM FApos -535 LETG Angle 76.09 PCONTROL AUTO Dec -62.297 Bus I 24.69 AOFSTAR BRIT Roll 274.825 ACA Object SSSSSSSS Dither DISA HRC-I HV OFF ACA ImFunc SSSSTTTT Dith Yang 0.00 Yaw Rate -0.54 HRC-S HV OFF ACA CCD Temp 42.9 Dith Zang 0.00 Pitch Rate -0.25 SHLD HV 0.0 ACA Int Time 0.705 Roll Rate 0.68 EVT RT 6119 AOACSTAT OK FSS SunBeta SUN SHLD RT 0 FSS Alfa -0.45 Batt 1 SOC 100.00% Avg HRMA Temp 75.78 FSS Beta -20.15 Batt 2 SOC 100.00% A -15 V -0.62 Avg OBA Temp 74.24 SA Resolv 109.89 Batt 3 SOC 100.00% A +15 V 2.81 OBA Tavg Fault NFLT SA Sun Pres ILLM A +5 V 4.84 OBA Trng Fault NFLT +Y SA Amps 12.37 A +24 V 0.00 HRMA power 0.00 SCS 128 DISA -Y SA Amps 12.18 OBA power 0.00 SCS 129 DISA +Y SA Temp 116.95 SCS 130 DISA -Y SA Temp 116.22 ACIS Stat7-0 6 Roll Mom. 0.024 SCS 131 DISA Cold Rad -127. Pitch Mom. -0.044 SCS 132 DISA Ephin Temp 0.0000 Warm Rad -86.9 Yaw Mom. -0.105 SCS 133 DISA EIO Temp 0.0000 RadMon DISA PMTANKP 137.343 SCS 107 DISA EPH temp 178.27 UpLCmdAcc 564 IRU2G2 curr 0.00 M Unload MON Cmd Rej A 88 IRU2G1 curr 0.00 Roll Bias -0.6765 TSC Move STOP Prop. line 03 175.74 Pitch Bias 0.2458 FA Move STOP CTX A PWR 36.27 Prop. line 04 168.93 Yaw Bias 0.5425 OTG Move DISA CTX A Volts 3.52 UTC 2023:047:13:52:02 (Feb16) f_ACE 1.85e+02 F_CRM 0.00e+00 Kp 4.3 R km 153316A Currently scheduled FPSI, OTG : HRC-S NONE Estimated Kp : 4.3 ACE EPAM P3 Proton Flux (p/cm^2-s-sr-MeV) : 1.85e+02 GOES-R P4 flux, in RADMON P4GM units : 0.137 GOES-R P7 flux, in RADMON P41GM units : 0.023 GOES-R E > 2.0 MeV flux (p/cm^2-s-sr) : 33.1 Orbit Start Time : 0.018 Geocentric Distance (km), Orbit Leg : 153299 A CRM Region : 3 (Magnetosphere) External Proton Flux (p/cm^2-s-sr-MeV) : 4.1070e+03 Attenuated Proton Flux (p/cm^2-s-sr-MeV) : 0.0000e+00 External Proton Orbital Fluence (p/cm^2-sr-MeV) : 1.2362e+06 Attenuated Proton Orbital Fluence (p/cm^2-sr-MeV) : 0.0000e+00