******************************************************************** UARS WEEKLY STATUS REPORT - 25 AUG 2000 ******************************************************************** *********** SOLSTICE *********** SOLSTICE is in good health, collecting solar data on all available orbital tracking periods and stellar calibration observations whenever possible. Our solar data is not affected by the larger than normal pointing errors since they are within our calibrations. Additionally, we continue to gather enough data to meet all the SOLSTICE science objectives during this period of reduced tape recorder operations. Level2 processing is halted due to bugs in the OA_SSPP_ATT service. CDHF and CSC personnel are working on the problem. *********** SUSIM *********** SUSIM continues to gather a normal set of daily solar scans scheduled for periods of predicted telemetry. *********** ACRIM *********** Nothing received. *********** PEM *********** The PEM zenith spectrometers are activate in daylight mode. At the present time, PEM energy deposition is not being generated. Recent data configuration changes have affected PEM software causing multiple failures. These failures are being reviewed by the PEM team. In order to correct for new telemetry requirements, PEM will need to update processing code with a patch delivery. The delivery patch will not include changes which would allow the PEM software to execute on a DEC Alpha machine. Updated HEPS calibration parameters have been finalized and are ready for delivery. Updated MEPS quality calibration files have been finalized and are ready for delivery. Level 3 software errors, discovered by Dr. Dean Pesnell, have been fixed; his suggestions have been incorporated with in the PEM production code. Both updated HEPS and MEPS calibration data, along with the Level 3 code changes, will influence the in-situ energy deposition predictions, so new versions of PEM energy deposition Level 3 files will be generated. *Beginning of power orbit day (PEM activation): array current >5 amps, array voltage >53.5 volts, and battery current >2.0 amps. End of power orbit day (PEM deactivation): time in power orbit day >4 minutes, array current <9 amps, and battery currents <0.2 amps. Power orbit day variation: ~39-40 min at yaw to ~50-51 min at maximum beta. *********** HALOE *********** Nothing received. *********** MLS *********** Nothing received. *********** HRDI *********** Nothing received. *********** WINDII *********** Nothing received. *********** MPG *********** The MPG participated in the meeting on Wednesday, 23 August, held to discuss the status of the ongoing efforts by the Flight Dynamics Facility and the Flight Operations Team to improve calibration of UARS Fixed Head Star Tracker 1. Processing of instrument Daily Activity Plans continues with no problems. We are continuing to coordinate with the Flight Operations Team and to assist the Project Scientist in the scheduling of instrument operations. *********** CDHF *********** Nothing received. *********** FOT *********** REPORTING PERIOD This report covers 12 August 2000 (Orbit 48752, GMT Day 225) through 18 August 2000 (Orbit 48855, GMT Day 231). SPACECRAFT OPERATION The observatory is now in Reverse Flight (Northern Hemisphere viewing) and is performing nominally under two-battery operations. The instrument operational changes were: INSTRUMENT OPERATIONAL CHANGES Instrument Time Orbit Comment ACRIM 226/1433 48775 Off SOLSTICE 226/1433 48775 Off SUSIM 226/1433 48775 Off ACRIM 229/0027 48811 On SOLSTICE 229/0027 48811 On SUSIM 229/1451 48820 On PEM 230/1129 48833 On - Day Only The beta angle ranged between the angles of 13.4 degrees to 15.5 degrees for this report period. The beta angle is now increasing toward a maximum angle of +49 degrees on 31 August 2000 (DOY 244). Spacecraft battery 1, 2, and 3 performance monitoring continues. Battery 1 remains OFF the charge relay. Battery 2 and Battery 3 are currently maintaining greater than 23.8 V end-of-night (EON) load bus voltage. Battery temperatures are stable with a temperature delta between Battery 2 and Battery 3 of 1.0 to 1.3 degrees C. Additional battery performance data for each battery on 11 August 2000 and 18 August 2000 are provided in Appendix D. The clock error ranged from -3.2 to 13.9 msec during this report period. Clock rate adjustments are listed in Appendix C. All instrument and subsystem engineers were advised on the initial excursion of ALERTS or Out-Of-Limits conditions detected by the FOT for this report. A summary is listed below and the details of ALERT and Out-Of-Limits occurrences are listed in Appendix B. ¥ OUT-OF-LIMITS = 00 ¥ ALERTS = 00 The following real-time command sheets were executed for the listed operational element(s) during this report period (see Appendix A). ¥ FOT = 17 ¥ SUSIM = 02 ¥ PEM = 02 ¥ ACRIM = 01 ¥ SOLSTICE = 01 ¥ SSPP = 01 ¥ HRDI = 01 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. ¥ FOT = 01 Two (2) Anomaly Reports remained OPEN at the end of this report period (see Appendix E). TRANSPONDER FREQUENCIES: · Transponder A: 00/153 - 2287.496961 · Transponder B: 00/213 - 2287.499288 GROUND SYSTEM OPERATION One (1) operational support problem occurred this period. Anomaly Reports are included in Appendix E. The data loss calculations supplied by Data Capture Facility (DCF) from mission start through UTC Day 00/230 show the observatory data loss to be 297 hours, 52 minutes, 39.185 seconds (an increase of 07 minutes 50.208 seconds since the last report period). This is a 0.40 percent data loss which equals a 99.60 percent data capture for the mission. The increase of 07 minutes 50.208 seconds occurred over three (3) days: · 02 minutes 51.296 seconds on Day 226 due to no acquisition. · 03 minutes 12.768 seconds on Day 228 due to no acquisition. · 01 minutes 46.144 seconds on Day 229 due to no acquisition. OTHER SIGNIFICANT EVENTS UARS SATELLITE OPERATIONS The FOT continues to operate FHST-1 for approximately one orbit each day. By cycling the tracker on and off for such a short duration the degradation seems to have been reduced significantly. Scale factor calibrations are being provided on a regular basis from FDF and are being uplinked when received. It appears that the FOT has been able to stabilize the performance of FHST-1 for now and continues to work on establishing another viable attitude control solution should the tracker fail. MEETINGS The FOT attended a meeting to discuss FHST-1 on 14 and 16 August 2000. FUTURE SIGNIFICANT EVENTS The next UARS Yaw slew is scheduled for September 17, 2000 (DOY 261). This maneuver will be a Reverse to Forward Flight maneuver (Southern Hemisphere viewing). Attachments: Appendix A, Real-time Commands Sheets Appendix B, Out-Of-Limits & ALERT Occurrences Appendix C, Clock & Solar Array Rate Corrections Appendix D, UARS Battery Performance Data Appendix E, UARS Anomaly Reports APPENDIX A REAL-TIME COMMAND SHEETS Week ending 18 Aug 2000 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------- 48761 225/1529 00-404 FHST-1 Power ON 48762 225/1750 00-404 FHST-1 Power OFF 48772 226/0848 00-412 HRDI STANDBY 48772 226/0928 00-413 PEM Power OFF 48775 226/1433 00-414 SSPP Power OFFSOLSTICE,SUSIM,ACRIM 48776 226/1532 00-404 FHST-1 Power ON 48777 226/1753 00-404 FHST-1 Power OFF 48789 227/1210 00-415 FHST1 Power ON 48789 227/1252 00-416 MACS YAW MANUEVER FWD TO REV 48792 22/1628 00-415 FHST1 Power OFF 48794 227/2102 00-417 FHST1 CALIBRATION 48806 228/1550 00-388 FHST-1 Power ON 48809 228/2011 00-388 FHST-1 Power Off 48811 229/0027 00-418 ACRIM Power ON 48811 229/0027 00-419 SOLSTICE Power ON 48820 229/1451 00-420 SUSIM Power ON 48832 230/0948 00-420 SUSIM Power ON(COMPLETE) 48833 230/1129 00-359 PEM Power ON(dayonly) 48835 230/1452 00-421 FHST-1 Scale factor update 38836 230/1557 00-422 FHST-1 Power ON 48837 230/1744 00-422 FHST-1 Power OFF 48853 231/1827 00-423 NBTR NOOPS D-232 48854 231/2010 00-424 FHST-1 FHST CALIBRATION 48854 231/2010 00-422 FHST-1 Power ON 48855 231/2154 00-422 FHST-1 Power OFF _______________________________________________________________________________ APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 18 Aug 2000 The following Out-Of-Limits occurrences were detected: MNEMONIC STATE DESCRIPTION ORBITS --------- ----- ------------ ------ None this report period The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS --------- ------------ ------ None this report period _______________________________________________________________________________ APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 18 Aug 2000 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ---- ----------------- None this report period ___________________________________________________________________________ APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 18 Aug 2000 11 Aug 2000 - GMT Day 224 Beta = 13.4 deg, SA Pos = 269 deg DIFF V (mV) TEMP (C) CURR (amp) EON V AVE C/D AVE BAT MAX/MIN MAX/MIN MAX/MIN MIN EON V AVE C/D AVE BAT MAX/MIN MAX/MIN MAX/MIN MIN RATIO DOD(%) --- ----------- --------- ---------- ------- ------- ------ 1 +459.2/+168.0 -3.05/-4.62 +0.0/+0.0 15.2 0.000 0.0 2 +33.6/-44.8 +5.79/+3.87 +29.6/-14.4 24.3 1.040 19.6 3 +22.4/-33.6 +4.83/+2.60 +28.8/-15.2 24.3 1.037 19.2 V/T LEVEL CHANGES ORB# TIME LVL FR-TO ----- ---------- ---------- no changes V/T 5 _______________________________________________________________________________ APPENDIX E UARS ANOMALY REPORTS Week ending 18 Aug 2000 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 00-040 FOT 48854 231/2111 22831 DATA DROPOUT ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- -None this report period ANOMALY INVESTIGATION REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- -None this report period OPEN ANOMALY REPORTS AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 00-037 FOT see list Aug 00 14170 Generic Late Acq. 00-032 FHST 48211 188/2242 N/A FHST 2 Anomaly SEVNTFW00/32