******************************************************************** UARS WEEKLY STATUS REPORT - 24 SEP 1999 ******************************************************************** *********** SOLSTICE *********** SOLSTICE continues to operate normally, collecting solar data on all available orbital tracking periods and stellar calibration observations, whenever possible. *********** SUSIM *********** The gridded offset maneuver performed last weekend mistakenly repeated one set of offsets. The impact is being assessed. Otherwise, SUSIM gathered its normal solar and occultation data this past week without apparent problems. *********** ACRIM *********** Nothing received. *********** PEM *********** The PEM spectrometers continue to be active under PMON control. While under PMON control, the PEM instrument computed energy deposition from its particle spectrometers. The FOT and the PEM team are updating the PEM activation sequence which effects the PEM/HEPS (> 30 keV particles). Current activation sequence reduces the activation time by about 1 minute. Additional analization shows that the activation sequence may be reduced by about another minute. PEM PMON activation is set for the beginning of power orbit day. The beginning of power orbit day is defined as when: array current greater than 5 amps, and array voltage greater than 53.5 volts, and any battery current greater than 2.0 amps The end of power orbit day (PEM deactivation) is defined as when: time in power orbit day greater than 4 minutes, and array current less than 9 amps, and all battery currents less than 0.2 amps Power orbit day periods vary depending upon beta angle: about 39-40 minutes at yaw about 50-51 minutes at max beta Current activation takes about 7.5 min for full activation. During the activation sequence, various components of PEM become active at all different times, beginning with the PEM magnetometer (at about on activation time) and ending with the HEPS-2 components (7.5 min later). *********** HALOE *********** Nothing received. *********** MLS *********** Nothing received. *********** HRDI *********** Nothing received. *********** WINDII *********** WINDII is next scheduled to operate on October 12-23. *********** 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. 13 days CLA (7.0) PROD (L1-L3) (473R-269C-16F=188L) 0 days GPI (4.05) PROD (CLAES L3B) (191R-164C-2F=25L) 0 days WIN (5.11A)TEST (L1-L3) (3R-0C-0F=3L) The CDHF has PCMB approval for the configuration and test of HALOE V4.82 formal delivery. WINDII 5.11A formal delivery needs PCMB approval for configuration. Three days are requested in test mode. CDHF personnel continued to draft procedures for the new Alpha 4000 and HSM systems. We have begun testing the new Rehost system by running the Production Program "Attitude Extraction" and performing a Level 0 Ingest. Once we have these successfully running we shall start on the PI Production Programs. *********** FOT *********** REPORTING PERIOD This report covers 11 September, 1999 (Orbit 43717, GMT Day 254) through 17 September 1999 (Orbit 43820, GMT Day 260). 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 WINDII 257/2218 43775 Off The beta angle ranged between the angles of 49.5 degrees to 27.4 degrees for this report period. The beta angle is now decreasing toward a minimum angle of -2 degrees on 24 September 1999 (DOY 267). 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 10 September 1999 and 17 September 1999 are provided in Appendix D. The clock error ranged from 10.3 to -10.8 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 = 04 % WINDII = 01 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. % FOT = 03 Four (4) Anomaly Report remained OPEN at the end of this report period (see Appendix E). TRANSPONDER FREQUENCIES: % Transponder A: 99/242 - 2287.496953 % Transponder B: 99/243 - 2287.499030 GROUND SYSTEM OPERATION Three (3) 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 99/259 show the observatory data loss to be 24 hours, 55 minutes, 17.108 seconds (an increase of 7.680 seconds since the last report period). This is a 0.0356 percent data loss which equals a 99.9644 percent data capture for the mission. The increase of 7.680 seconds occurred over one (1) day: 7 7.680 seconds on Day 257 due to an IP line hit. OTHER SIGNIFICANT EVENTS UARS SATELLITE OPERATIONS PEM requested to have the timing in their turn on sequence tightened up in yet another area. This is expected to be accomplished within the next few weeks. YEAR 2000 OPERABILITY SUPPORT End-to-end Y2K testing continued this past week. The FOT received the Brower Mean Element report from FDF, but are still waiting for a valid 8-week PSAT file to be used for testing. Without a complete set of 8-week files, the UARS CMS is unable to perform all of the necessary mission planning and load building processes required for Y2K end-to-end testing. In the meantime, the FOT has generated a "test" Y2K ATC load by editing an existing 1999 load, and performing a universal substitution edit command on the year, changing it from 1999 to 2000. This ATC load was tested on the simulator and worked properly. MEETINGS None FUTURE SIGNIFICANT EVENTS A meeting to discuss the UARS Safehold configuration and concerns for the MPS and its batteries is planned for September. This meeting will be a closed meeting with only the FOT and specialized engineering support attending. 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 17 September 1999 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------- 43724 254/1158 99-320 OBC Clk Adj fr 0.00 to 20.6 msec/day 43751 256/0703 99-321 OBC Clk Adj fr 20.6 to 0.00 msec/day 43775 257/2218 99-322 WINDII Power OFF 43794 259/0442 99-323 OBC Clk Adj fr 0.00 to 20.6 msec/day 43814 260/1159 99-324 OBC Clk Adj fr 20.6 to 0.00 msec/day __________________________________________________________________________ APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 17 September 1999 MNEMONIC STATE DESCRIPTION ORBITS --------- ----- ------------ ------ HRPTSPBIMON Y-HI HRDI PTS PB Current Mon 43792,97 HRPSEQBIMON Y-HI HRDI PSE QB Current Mon 43797 The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS --------- ------------ ------ No Alerts to report this report period. ____________________________________________________________________________ APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 17 September 1999 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ---- ----------------- 43724 254/12:03 (11 Sept 99) from 00.0 to 20.6 msec/day 43751 256/07:08 (13 Sept 99) from 20.6 to 00.0 msec/day 43794 259/04:47 (16 Sept 99) from 00.0 to 20.6 msec/day 43814 260/12:06 (17 Sept 99) from 20.6 to 00.0 msec/day APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 17 September 1999 10 Sept 1999 - GMT Day 253 Beta = 47.3 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 -112.0/-134.4 -3.05/-4.31 +0.0/+0.0 16.5 0.000 0.0 2 +39.2/-11.2 +5.79/+4.19 +27.2/-16.0 24.5 1.024 21.0 3 +44.8/-33.6 +4.83/+3.23 +26.8/-16.0 24.3 1.024 20.8 17 Sept 1999 - GMT Day 260 Beta = 27.4 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 RATIO DOD(%) --- ---------- -------- ---------- ----- ------- ------ 1 -112.0/-134.4 -2.73/-4.31 +0.0/+0.0 16.5 0.000 0.0 2 +33.6/-22.4 +6.44/+5.15 +30.4/-15.2 24.5 1.022 22.0 3 +67.2/-16.8 +5.15/+3.87 +29.6/-16.4 24.5 1.025 21.8 V/T LEVEL CHANGES ORB# TIME LVL FR-TO ----- ---------- ---------- no changes V/T 5 APPENDIX E UARS ANOMALY REPORTS Week ending 17 September 1999 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 99-055 FOT 43768 257/1029 N/A TAC Crashed 99-056 FOT 43778 258/0336 N/A TAC 8 Crashed 99-057 FOT 43809 260/0439 21348 PTP FAILURE, REBOOTED 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 ------ ------ ----- ---- --- ----------------- 99-058 FOT see list Sept 99 14170 Generic Late Acq. 99-055 FOT 43768 257/1029 N/A TAC Crashed 99-056 FOT 43778 258/0336 N/A TAC 8 Crashed 99-057 FOT 43809 260/0439 21348 PTP FAILURE, REBOOTED SEVNTFW99/38