******************************************************************** UARS WEEKLY STATUS REPORT - 21 MAY 1999 ******************************************************************** *********** SOLSTICE *********** SOLSTICE continues to operate normally, collecting solar data on all available orbital tracking periods and stellar calibration observations, whenever possible. *********** SUSIM *********** SUSIM gathered its normal solar, offset, and occultation data without apparent problems. *********** PEM *********** PEM/AXIS was active from May 14 through May 18. During this time, PEM/AXIS generated deposition profiles from electron precipitation which were inverted from measured X-rays. PEM, active under PMON control, was terminated on May 18 due to a large energy drain on the UARS spacecraft. While under PMON control, the PEM instrument computed energy deposition from its particle spectrometers. The FOT and the PEM team are completing close-out documentation on the HEPS Energy Processor trouble; however progress has been hampered with the departure of Peter Thomas. *********** HALOE *********** HALOE has been successfully operating. Presently, HALOE is off, but is scheduled to be powered on beginning of day May 29, 1999. *********** MLS *********** MLS was reactivated successfully on May 11 and operated until May 19 13:27 UTC when the FOT needed to turn MLS off due to power constraints. MLS was reactived on May 20 and is scheduled to operate through May 28. *********** HRDI *********** Nothing received. *********** WINDII *********** Nothing received. *********** MPG *********** Routine processing of instrument Daily Activity Plans continues with no problems. The MPG continues to assist the Project Scientist with the scheduling of instrument operations. *********** CDHF *********** The CDHF processed current day data through level 3 for all active instruments. Additionally, CDHF personnel reprocessed: (R)= Requested (C) = Complete, (F)= Failed (L) = Days remaining to reprocess. 2 days CLA (7.0) PROD (L1-L3) (22R-12C-4F=6L) 2 days HAL (4.81) PROD (L1-L3) (2R-2C=0L) 2 day HRD (4.4) PROD (L1-L3)(TEST) (2R-2C=0L) 50 days PEM (3.32) PROD (OA-L2) (753R-718C-1F=34L) 55 days WIN (5.11) PROD (LOG) (1540R-1540C=0L) 62 days WIN (5.11) PROD (L1-L3) (1540R-512-4F=1024L) March 1999 current day DAAC data will be loaded in May 1999. CDHF pending software upgrades: DEC AXP Fortran 6.5, DEC AXP OPEN VMS 6.2, OpenIngres. *********** FOT *********** REPORTING PERIOD This report covers 08 May 1999 (Orbit 41830, GMT Day 128) through 14 May 1999 (GMT Day 134). SPACECRAFT OPERATION The observatory is now in Forward Flight (Southern Hemisphere viewing) and is performing nominally under two-battery operations. The instrument operational changes were: INSTRUMENT OPERATIONAL CHANGES Instrument Time Orbit Comment ACRIM 130/2230 41873 Off MLS 131/0006 41874 On SOLSTICE 131/0015 41874 Day Only HRDI 131/0336 41876 Day Only HALOE 133/2246 41918 Off SOLSTICE 134/0025 41919 Full Time ACRIM 134/0059 41919 On WINDII 134/0059 41919 On PEM 134/1126 41926 AXIS On The beta angle ranged between the angles of 26.0 degrees to 55.9 degrees for this report period. The beta angle is now increasing toward a maximum angle of 77 degrees on 21 May 1999 (DOY 141). 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 0.7 to 1.3 degrees C. Additional battery performance data for each battery on May 07 1999 and May 14 1999 are provided in Appendix D. The clock error ranged from 11.1 to -11.2 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. % ALERTS = 00 % OUT-OF-LIMITS = 02 The following real-time command sheets were executed for the listed operational element(s) during this report period (see Appendix A). % FOT 03 % ACRIM 02 % PEM 02 % MLS 01 % HRDI 01 % HALOE 01 % WINDII 01 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. % FOT 01 % HRDI 01 One (1) Anomaly Report remained OPEN at the end of this report period (see Appendix E). TRANSPONDER FREQUENCIES: Transponder A: 99/117 - 2287.496987 Transponder B: 99/118 - 2287.498739 GROUND SYSTEM OPERATION Two (2) operational support problems 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 99/119 show the observatory data loss to be 24 hours, 12 minutes, 39.348 seconds (an increase of 2.240 seconds since the last report period). This is a 0.0361 percent data loss which equals a 99.9639 percent data capture for the mission. The increase of 2.240 seconds occurred over five (3) days: 7 1.056 seconds on Day 127 due to a data hit, 7 0.672 seconds on Day 132 due to a data hit, 7 0.512 seconds on Day 133 due to a data hit. OTHER SIGNIFICANT EVENTS UARS SATELLITE OPERATIONS FOT personnel are supporting the IMOC (SCS-21) development effort. The current work is a continuation of the SCS-21 UARS implementation effort done last year which culminated in a level 1 demonstration. The FOT continues to investigate the feasibility of a new PMON action to change battery V/T curves based on loading to mitigate battery risks in sun pointing safehold. YEAR 2000 OPERABILITY SUPPORT The end-to-end testing that was scheduled to start this week has been delayed until next week to allow additional time for FDF to create special Y2K planning aids. UARS PROPULSION MODULE B/D THRUSTER LINE FILL - No change MEETINGS FOT attended the weekly IMOC meetings on 12 May 1999. FUTURE SIGNIFICANT EVENTS The next UARS Yaw Around Maneuver (forward-to-reverse) is scheduled for 11 June 1999 (DOY 162). PERSONNEL CHANGES None 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 14 May 1999 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------- 41845 129/0139 99-159 OBC Clk Adj fr 0.00 to 20.6 msec/day 41871 130/1942 99-160 OBC Clk Adj fr 20.6 to 0.00 msec/day 41873 130/2230 99-161 ACRIM Power OFF 41874 131/0006 99-162 MLS Power ON 41876 131/0336 99-163 HRDI Day only operations 41903 132/2228 99-164 OBC Clk Adj fr 0.00 to 20.6 msec/day 41918 133/2246 99-165 HALOE Power OFF 41919 134/0059 99-166 ACRIM Power ON 41919 134/0059 99-167 WINDII Power ON 41926 134/1126 99-168 PEM AXIS 1&2 ON 41930 134/1747 99-169 PEM PEM CALS _______________________________________________________________ APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 14 May 1999 MNEMONIC STATE DESCRIPTION ORBITS --------- ----- ------------ ------ WIISUTEMP Y-LO WINDII ISU Temp 41881-88 WIISUTEMP Y-LO WINDII ISU Temp continuous SORLGCTMP Y-LO Logic_Box Temperature continuous The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS --------- ------------ ------ None this report period _______________________________________________________________ APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 14 May 1999 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ---- ----------------- 41845 129/01:39 (08 May 99) from 00.0 to 20.6 msec/day 41871 130/19:42 (10 May 99) from 20.6 to 00.0 msec/day 41903 132/22:28 (12 May 99) from 00.0 to 20.6 msec/day APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 14 May 1999 07 May 1999 - GMT Day 127 Beta = 26.0 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 RATIO DOD(%) --- ------------ ---------- ----------- ------- ------- ------ 1 -78.4/-100.8 -3.05/-4.31 +0.0/ +0.0 16.5 0.000 0.0 2 +39.2/-16.8 +6.11/+4.83 +30.4/-15.2 24.8 1.023 22.1 3 +22.4/-50.4 +5.15/+3.87 +30.4/-16.0 24.8 1.024 22.0 14 May 1999 - GMT Day 134 Beta = 55.9 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 RATIO DOD(%) --- ------------ ---------- ----------- ------- ------- ------ 1 -78.4/-112.0 -3.68/-4.94 +0.0/ +0.0 16.5 0.000 0.0 2 +22.4/-28.0 +5.15/+3.87 +24.8/-16.4 23.8 1.013 21.0 3 +22.4/-50.4 +4.51/+2.60 +24.8/-17.2 23.8 1.016 20.8 V/T LEVEL CHANGES ORB# TIME LVL FR-TO ----- -------- ---------- no changes V/T 5 APPENDIX E UARS ANOMALY REPORTS Week ending 14 May 1999 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 99-026 HRDI 41875 131/0148 N/A Not in Day Only as Scheduled 99-023 FOT 41929 134/1604 14170 Generic Late Acquisition ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 99-024 FOT 41741 122/0302 20809 Late Acquisition 99-026 HRDI 41875 131/0148 N/A Not in Day Only as Scheduled ANOMALY INVESTIGATION REPORTS GENERATED AIR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------- ------ ----- ---- --- ----------------- None this report period OPEN ANOMALY REPORTS AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 99-023 FOT see list May 99 14170 Generic Late Acq SEVNTFW99/20