******************************************************************** UARS WEEKLY STATUS REPORT - 01 JAN 1999 ******************************************************************** *********** SOLSTICE *********** SOLSTICE continues to operate normally, collecting solar data on all available orbital tracking periods and stellar calibration observations, whenever possible. Happy New Year! *********** SUSIM *********** SUSIM was off between 12/23/98 and 12/30/98. On all other days SUSIM successfully gathered its normal solar, offset, and occulation data without apparent problems. Reprocessing of all SUSIM experiment days to version 20 continues. *********** PEM *********** A Happy New Year to all from the PEM team!! PEM conducting tests of the OBC activation. PEM activation occurs during daylight only, when there is adequate power generated from the UARS solar array. Currently, the PEM magnetometer and medium energy spectrometers (particles below 30 keV) activate correctly under OBC control. Tests conducted on the high energy particle spectrometers (HEPS -- particles greater than 30 keV) have had limited success. New OBC activation procedure for HEPS based on previous tests has been created. Tests of the new activation sequence has begun. The first of nine tests was successful. Due to testing, HEPS science data from December 1 to December 15 and after December 17 should be considered invalid and not used. *********** HALOE *********** Nothing received. *********** MLS *********** Nothing received. *********** 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 has received a total of 452 CD-ROM requests as of 1-January-1999. There were three orders received and shipped. 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. 70 days HAL (4.80) PROD (L3) (1874R-1721C-1F=152L) 31 days SOL (4.62) PROD (L2-L3) (2313R-2307C=6L) 132 days SUS (7.00) PROD (L3) (2540R-1100C-6F=1434L) Plans continue for SOLSTICE to be run with debug in UCSS production. This should aid in defining the cause of SOLSTICE wall clock time increases. DAAC data created in the month of October 1998 for HALOE, HRDI, PEM, NMC, and UKMO has been loaded into the DAAC Transfer Tables. CDHF pending software upgrades: IDL 5.03, OpenIngres, UCSS 10.1, MSS 4.1, NRT 2.5, UOAS 5.4 . *********** FOT *********** REPORTING PERIOD This report covers 19 December 1998 (Orbit 39732, GMT Day 353) through 25 December 1998 (Orbit 39836, GMT Day 359). SPACECRAFT OPERATION The observatory is now in Forward Flight (Southern Hemisphere viewing) with a +0.5 degree Roll (cold side down) and is performing nominally under two- battery operations. The instrument operational changes were: INSTRUMENT OPERATIONAL CHANGES Instrument Time Orbit Comment WINDII 353/0005 39732 On WINDII 353/0144 39733 Off WINDII 354/0302 39749 On ACRIM 357/2209 39806 Off SUSIM 357/2209 39806 Off PEM 357/2346 39807 Axis Off WINDII 357/2346 39807 Off MLS 358/0134 39808 On The beta angle ranged between 16.7 degrees to 32.2 degrees for this report period. The beta angle is now increasing toward a maximum angle of 34.0 degrees on 27 December 1998 (DOY 361). As beta angle (and average power margin) increased this week, Battery 3 differential voltage decreased as expected. As a precaution, online and offline personnel are monitoring the power subsystem with increased vigilance for any unexpected behavior. A +0.5 Degree Roll Offset Maneuver (cold side down) was performed on 17 December (DOY 351) in Orbit 39713 at 351/14:54:57. The maneuver was requested by the WINDII instrument to facilitate the observation of Polar Mesospheric Clouds. UARS will return to level flight on 11 January 1999 (DOY 011). The exact time for the return maneuver has not been finalized. 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 0.9 to 1.3 degrees C. Additional battery performance data for each battery on 18 December 1998 and 25 December 1998 are provided in Appendix D. The clock error ranged from -11.3 to 11.4 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 = 01 The following real-time command sheets were executed for the listed operational element(s) during this report period (see Appendix A). % FOT 03 % ACRIM 01 % MLS 10 % PEM 01 % SUSIM 01 % WINDII 04 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. % FOT 03 Two (2) Anomaly Report remained OPEN at the end of this report period (see Appendix E). TRANSPONDER FREQUENCIES: Transponder A: 98/286 - 2287.496936 Transponder B: 98/300 - 2287.498964 GROUND SYSTEM OPERATION Three (3) operational support problems occurred this period. Anomaly Reports are included in Appendix E. There are two open Anomaly Report. The data loss calculations supplied by Data Capture Facility (DCF) from mission start through UTC Day 98/358 show the observatory data loss to be 21 hours, 40 minutes, 28.632 seconds (an increase of 01.216 seconds since last report period). This is a 0.0341 percent data loss which equals a 99.9659 percent data capture for the mission. The increase of 01.216 seconds occurred over two (2) days: 7 0.224 seconds on Day 356 due dat hit. 7 0.992 seconds on Day 357 due to hit in data (IP). OTHER SIGNIFICANT EVENTS UARS SATELLITE OPERATIONS Development of the procedure for the clock change to include the 01 January 1999 leap second adjustment is complete. A new ephemeris will be started immediately after the OBC clock is adjusted. No impact on spacecraft pointing is expected. PEM testing, contingency operation simulation, and orbit adjust simulations were suspended this week in order to support current operations. PEM testing will resume on the 28th. The FOT is investigating the feasibility of a new PMON action to change battery V/T curves based on loading to mitigate battery risks in sun pointing safehold. The FOT discussed planning and other procedures for day-only operations and mode transitions with instrument teams. SOLSTICE ON to DAY-ONLY transition was successfully executed by ATC commands built from an instrument DAP on day 358. It appears that since SOLSTICE is cycling they are not generating their normal amount of heat and therefore they, along with the other SSPP instruments, are getting a little cold. The FOT will analize the data for this weekend and come up with some possible solutions for this problem. YEAR 2000 OPERABILITY SUPPORT UARS Test and Training Simulator (UTTS) - No change. User Planning System (UPS) - No Change Multi Satellite Operations Control Center (MSOCC) - No change. Command Management System (CMS) - No Change Flight Dynamics Facility (FDF) - No change. UARS PROPULSION MODULE B/D THRUSTER LINE FILL Planning continues for the simulator testing. UARS RE-ENGINEERING - TELEMETRY PROCESSING No change. A new release is expected in the near future. MEETINGS None FUTURE SIGNIFICANT EVENTS The next UARS Yaw Around Maneuver is scheduled for scheduled for 11 January 1999. The United States Naval Observatory (USNO) issued a Time Service announcement advising that the International Earth Rotation Service (IERS) will retard UTC time by 1.0 second at the end of December 1998. This means the addition of one leap second as the last second of 1998. The next annular solar eclipse will occur on 16 February 1999 over the Indian Ocean, Australia and the South Pacific Ocean. 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 18 December 1998 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------- 39732 353/0005 98-503 WINDII Power ON 39733 353/0144 98-504 WINDII Pwr OFF 39749 354/0302 98-503 WINDII Power ON 39750 354/0446 98-505 OBC Clk Adj fr 20.6 to 0.0 ms/day 39806 357/2209 98-506 ACRIM Power OFF 39806 357/2209 98-507 SUSIM Power OFF 39807 357/2346 98-508 PEM AXIS Power Off 39807 357/2346 98-509 WINDII Power OFF 39808 358/0134 98-510 MLS Power ON 39810 358/0500 98-511 OBC Clk Adj fr 0.0 to 20.6 ms/day 39823 359/0139 98-512 MLS Excep Clear 39824 359/0322 98-512 MLS Excep Clear 39825 359/0503 98-512 MLS Excep Clear 39826 359/0643 98-512 MLS Excep Clear 39827 359/0823 98-513 MLS Scan Actuator OFF 39834 359/1853 98-514 MLS Scan Actuator ON 39835 359/2025 98-512 MLS Excep Clear 39835 359/2107 98-512 MLS Excep Clear 39836 359/2247 98-512 MLS Excep Clear 39836 359/2247 98-515 OBC Clk Adj fr 20.6 to 0.0 ms/day _______________________________________________________________ APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 18 December 1998 MNEMONIC STATE DESCRIPTION ORBITS --------- ----- ------------ ------ HRPSEQBIMON Y-HI PSE Quiet Bus Current Monitor 39769 The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS --------- ------------ ------ None this report period _______________________________________________________________ APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 25 Dec 1998 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ---- ----------------- 39750 354/04:46 (20 Dec 98) from 20.6 to 00.0 msec/day 39810 358/05:04 (24 Dec 98) from 00.0 to 20.6 msec/day 39836 359/22:51 (25 Dec 98) from 20.6 to 00.0 msec/day _______________________________________________________________ APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 25 Dec 1998 18 Dec 1998 - GMT Day 352 Beta = 16.7 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 +67.2/+44.8 -3.05/-4.31 +0.0/ +0.0 16.8 0.000 0.0 2 +22.4/-44.8 +6.11/+4.83 +32.0/-14.4 25.3 1.024 21.9 3 +190.4/+22.4 +5.15/+3.87 +31.2/-15.2 25.1 1.022 21.7 25 Dec 1998 - GMT Day 3359 Beta = 32.2 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 +61.6/+39.2 -2.73/-3.99 +0.0/ +0.0 16.8 0.000 0.0 2 +11.2/-67.2 +6.11/+5.15 +30.4/-15.2 25.3 1.028 21.8 3 +134.4/11.2 +5.15/+3.87 +30.0/-16.4 25.1 1.024 21.7 V/T LEVEL CHANGES ORB# TIME LVL FR-TO ----- -------- ---------- no changes V/T 5 APPENDIX E UARS ANOMALY REPORTS Week ending 18 December 1998 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 98-117 FOT 39737 353/0702 14170 Generic Late Acq 98-123 FOT 39788 356/1745 N/A AP/ODN DOWN 98-117 FOT 39806 357/2209 14170 Generic Late Acq ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 98-122 FOT 39639 346/18:14 CMD BUFFER PROB 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 ------ ------ ----- ---- --- ----------------- 98-117 FOT 39737 353/0702 14170 Generic Late Acq 98-123 FOT 39788 356/1745 N/A AP/ODN DOWN 98-117 FOT 39806 357/2209 14170 Generic Late Acq SEVNTFW52