SOT Shift Report Shift M793 Duration: 22 Sep 2001 12:00 EDT - 22 Sep 2001 23:00 EDT 22 Sep 2001 16:00 GMT - 23 Sep 2001 03:00 GMT SOT Lead: Tom Aldcroft Spacecraft/Aspect: FOT/Science Liason: HRC: Jon Chappell ACIS: ======================================== Plan ---- Recover from Bright Star Hold to Normal Point Mode. See below for details on entry into Bright Star Hold. Events ------ 265:11:48 Entry into Bright Star Hold 16:40 AOS on DSS-66 266:02:16 Start BSH recovery SOP_SAFE_BRIGHT_STAR_HOLD_RECOVERY 02:48 BSH recovery successful. Now holding on stars in NPM. Notes/Issues/Problems --------------------- - ACE rates very low - Entry into Bright Star Hold, from RJB: This morning (22 Sept) Chandra entered a bright star hold at 7:48am (265/11+48) following a 2.5 hour observation of the dark moon performed on gyro-hold. Analysis of the dump data indicates that a gyro bias error of ~170 arcsec accumulated during the gyro hold and subsequent maneuver. The error exceeded the size of the aspect camera search box during the next star acquisition and resulted in the bright star hold. Data indicates that the gyro performance is consistent with past performance, however some further data analysis will be performed by the gyro vendor. The plan is to recover normal point mode tonight and re-join the science time-line after the next perigee passage early on Monday morning, at the start of next weeks load. Snapshot -------- Snapshot shows expected state after entry to BSH and running of SCS107: UTC 2001:266:01:32:25 (Sep23) f_ACE 8.11e+01 F_CRM 1.65e+08 Kp 1.3 R km 131382D OBT 2001:266:01:31:43 CTUVCDU 12019074 OBC s/w NRML FMT2_NORM CPEstat NORM OBT 117595903.63 ONLVCDU 12019064 OBC Errs 0 OBSID 61463 EPState SUN SIM TTpos -99616 HETG Angle 79.84 PCADMODE NPNT RA 244.874 Bus V 30.55 SIM FApos -535 LETG Angle 77.96 PCONTROL NPNT Dec -39.683 Bus I 29.50 AOFSTAR BRIT Roll 253.547 ACA Object SSSSSSSS Dither ENAB HRC-I HV OFF ACA ImFunc TTTTTNTT Dith Yang 1.88 Yaw Rate 0.08 HRC-S HV ON ACA CCD Temp -10.4 Dith Zang 5.62 Pitch Rate 0.13 OBSMode NEXT ACA Int Time 0.705 Roll Rate -0.08 Door OP UNAC AOACSTAT OK FSS SunBeta SUN Door CL UNAC FSS Alfa -0.49 Batt 1 SOC 100.00% Avg HRMA Temp 70.61 FSS Beta 18.80 Batt 2 SOC 100.00% ACIS Stat7-0 66 Avg OBA Temp 51.37 SA Resolv 71.43 Batt 3 SOC 100.00% Cold Rad -127.9 OBA Tavg Fault NFLT SA Sun Pres ILLM Warm Rad -84.4 OBA Trng Fault NFLT +Y SA Amps 14.30 RadMon DISA HRMA power 32.70 SCS 128 INAC -Y SA Amps 15.07 EPHIN Geom LARG OBA power 94.40 SCS 129 INAC +Y SA Temp 110.51 E150 1.7 SCS 130 INAC -Y SA Temp 111.12 E300 0.1 Roll Mom. -1.953 SCS 107 DISA E1300 0.0 Pitch Mom. -15.169 UpL Cmd Acc 50184 EPH A-Leak 1.0200 P4GM 0.0 Yaw Mom. -1.719 Cmd Rej A 13 EPH B-Leak 0.2600 P41GM 0.0 Explanation Current Data: UTC 2001:266:01:32:40 (Sep23) f_ACE 8.11e+01 F_CRM 1.65e+08 Kp 1.3 R km 131382D Currently scheduled FPSI, OTG : HRC-S NONE Costello Kp : 1.33 ACE EPAM P3 Proton Flux (p/cm^2-s-sr-MeV) : 8.11e+01 Orbit Start Time : 2001:264:09:24:00 Geocentric Distance (km), Orbit Leg : 131494 D CRM Region : 3 (Magnetosphere) External Proton Flux (p/cm^2-s-sr-MeV) : 5.88487000000e+02 Attenuated Proton Flux (p/cm^2-s-sr-MeV) : 0.00000000000e+00 External Proton Orbital Fluence (p/cm^2-sr-MeV) : 5.87507909310e+08 Attenuated Proton Orbital Fluence (p/cm^2-sr-MeV) : 1.65177258600e+08