******************************************************************** UARS WEEKLY STATUS REPORT - 8 MAY 1998 ******************************************************************** *********** SOLSTICE *********** SOLSTICE continues to operate normally, collecting solar data on all available orbital tracking periods and stellar calibration observations, whenever possible. *********** SUSIM *********** SUSIM has successfully gathered its normal solar, offset, and occultation scan data without apparent problems. *********** PEM *********** PEM is not active. GSFC has proposed an OBC operation plan for the activation of PEM boom instruments during the daylight portions of every orbit. This OBC operation plan is under evaluation by PEM. *********** HALOE *********** Nothing received. *********** MLS *********** MLS was reactivated successfully on Apr 29, in the reduced 85 watt power mode. MLS instrument operations have continued flawlessly. MLS was powered off May 2 at 23:32 UT. MLS is scheduled to begin south viewing operations starting May 20. *********** HRDI *********** Nothing received. *********** WINDII *********** Nothing received. *********** MPG *********** Routine processing of instrument Daily Activity Plans continues with no other problems. The MPG continues to assist the Project Scientist with the scheduling of instrument operations. *********** CDHF *********** The CDHF receieved Level 0 for UARS days 2417, 2418, 2419 and 2420 on 05/03 and 05/04. These days were delayed due to the building power outage on 04/24 through 04/27. The CDHF has received a total of 386 CD-ROM requests as of 08-May-1998. No new orders were received. The CDHF receieved UKMO Day 2263 and 2264. 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. 43 days PEM (3.32) PROD (1379R-1212C=167L) 2 days HAL (4.80) PROD (Test) (2R-2C=0L) 1 days WIN (5.1) ENG (1R-1C=0L) CDHF worked on proposed UARS CDHF system configuration changes and associated improvements and impacts. *********** NOAA DATA *********** NOTICE OF CHANGE IN TEMPERATURES FROM NCEP ANALYSES On May 1, 1998 NCEP operational stratospheric analyses began using RTOVS (Revised TIROS Operational Vertical Soundings) from the NOAA-14 satellite. TOVS data had been produced by NESDIS (National Environmental Satellite Data and Information Service) from the operational NOAA series of satellites for the last two decades. RTOVS was introduced as a transition to ATOVS (Advanced TOVS), in preparation for the launch of NOAA-K later this month (May 13, 1998). Once operational, NOAA-K becomes NOAA-15. TOVS and RTOVS soundings use data from the Stratospheric Sounding Unit (SSU), the Microwave Sounding Unit (MSU), and the High resolution InfraRed Sounder (HIRS). ATOVS will derive soundings from the HIRS and the Advanced Microwave Sounding Unit (AMSU). Comparisons to radiosonde data show general improvement with RTOVS data. Average RTOVS/TOVS differences at the various pressure levels change in magnitude and sign with season and latitude, but in general are less than 1 K degree. In some instances, differences of up to 3 K apparent. For more information, contact Mel Gelman at melvyn.gelman@noaa.gov or at 301-763-8000 x7558. *********** FOT *********** REPORTING PERIOD This report covers 24 April 1998 (Orbit 36169, GMT Day 115) through 01 May 1998 (Orbit 36272, GMT Day 121). 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 HRDI 115/0205 36170 On HALOE 118/2304 36228 Off MLS 119/0039 36229 On HRDI 120/1115 36250 Off A summary of Instrument operations supplied by the Mission Planning Group for the month of April 1998 is contained in Appendix F, UARS Instrument Operations Summary. The beta angle is now decreasing toward a minimum angle of 0.0 degrees on 05 May 1998 (DOY 125). 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 24.2 V end-of-night (EON) load bus voltage. Battery temperatures are stable with a temperature delta between Battery 2 and Battery 3 of 1.2 degrees C. Additional battery performance data for each battery on 25 April 1998 and 01 May 1998 are provided in Appendix D. The clock error ranged from -10.9 to +11.8 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 = none % OUT-OF-LIMITS = 08 The following real-time command sheets were executed for the listed operational element(s) during this report period (see Appendix A). % FOT 03 % HALOE 01 % HRDI 02 % MLS 01 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. % FOT 01 One (1) Anomaly Reports remained OPEN at the end of this report period (see Appendix E). TRANSPONDER FREQUENCIES: Transponder A: 98/062 - 2287.496945 Transponder B: 98/062 - 2287.497010 GROUND SYSTEM OPERATION No (0) operational support problem(s) 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 98/120 show the observatory data loss to be 20 hours, 43 minutes, 08.788 seconds (an increase of 14.624 seconds since last report period). This is a 0.0358 percent data loss which equals a 99.9642 percent data capture for the mission. The increase of 14.624 seconds occurred over a three day period: 7 9.888 seconds on Day 115 due to hits in the data, 7 0.448 seconds on Day 116 due to hits in the data, and 7 4.288 seconds on Day 117 due to hits in the data. The FOT EXPERIENCED along-track ephemeris transition comparisons in excess of 1.5 km when processing the ephemeris in the Command Management System (CMS) software this week. The out-of-limit comparisons occurred on two of the three ephemeris delivery days. The FOT will contact FDF next week to discuss the status of their investigation into the need for more frequent spacecraft ephemeris deliveries. The FOT performed a limited amount of IP testing this week. As with previous testing, the FOT ran a spare AP in a parallel environment to monitor I-channel return telemetry. The FOT also attempted to monitor Q- channel OBC dumps via the IP system, but was unsuccessful. On one event, the TAC crashed before the Q-channel dump was started. On a second event, the TAC locked on the Q-channel data, but the dump compare was never conducted on the AP. This was probably due to an operational or AP configuration problem by the FOT. Investigation is underway as to what the FOT must due to achieve a successful Q-channel OBC dump. Further testing is planned for next week The FOT continued making modifications to the OBCSTF resident POCC database this week. The number of additions, deletions, and modifications has turned out to be far more extensive than originally thought. In addition, the FOT has been having intermittent problems with the OBCSTF terminal Rlocking upS during database entry. The majority of the database modifications have been completed, but many hours worth of work still remain. The database work is expected to be completed by 06 May 1998. The FOT made a few modifications to the new CMS versions of Relative Time Sequences (RTSs) 39 and 40 this week. The changes were necessary to preclude the need for frequent RTS reloading to properly control the SOLSTICE instrument. The modifications were coordinated the SOLSTICE operations team. The FOT received requests from SOLSTICE operations to perform two manually generated SSPP Stellar Offset experiments on GMT days 125 and 127. The second Building 23 power outage began on schedule at noon on 24 April 1998 and continued without event until 27 April 1998. All data has been recovered from White Sands Ground Terminal. Four days of level-0 data is missing (24 April to 27 April) on the CDHF system due to the weekend power outage at the close of this report period. RDummyS telemetry files were created for the missing days to allow daily UGPL products to run during the week. The missing days are planned to be processed over the weekend of 02-03 May, and the RdummyS files will be replaced with actual data the following Monday (04 May). Post-status note: All missing level-0 data was processed by about noon today (04 May), and UGPL products have been restored to nominal operation. All data is included in the data quality statistics at the beginning of this section. OTHER SIGNIFICANT EVENTS Work on the upgrade of the OBC Power Monitor (PMON) continued. FOT coordinated with PEM, MLS, and SOLSTICE for inputs to new PMON software (these instruments primarily affected by changes) this week. New operations scenarios for each of these instruments, including new ground database commands, telemetry, and RTS/PDB definitions were generated. Work continues on the UARS August orbit adjust planning. FOT continues to support CNMOS in their efforts to make necessary software changes (MSOCC, CMS, DCF, etc.) to support the year 2000 rollover. Monitoring of the magnetic field model performance continues. FOT continues to improve a Power Profile for UARS based on the current status of the Modular Power System. FOT continues to support the new UARS ground system re-engineering effort. A response to a list of questions was prepared for distribution this week. MEETINGS No UARS Battery telecon was held this week. The next telecon has not been scheduled. A follow-up meeting to discuss and confirm the changes made to the OBC Ground Image to support the OBC Flight Software update was held on 30 April 1998. A decision was reached to proceed with the development/release of Version 10.11 of the Application Processor software to support the OBC PMON update. An operational pack will be available by the end of May 1998. FOT will conduct testing of the software and data base changes using the 10.11 version test pack while the official release process and operational pack generation takes place. FUTURE SIGNIFICANT EVENTS The next UARS Yaw Around Maneuver is currently scheduled for 05 May 1998. The UARS orbit altitude is dropping slowly and a drag makeup orbit adjust is targeted for 05 August 1998. 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 F, UARS Instrument Operations Summary APPENDIX A REAL-TIME COMMAND SHEETS Week ending 01 May 1998 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------- 36170 115/0205 98-149 HRDI Power ON 36180 115/1736 98-150 OBC Clk Adj fr 0.00 to 20.6 msec/day 36209 117/1636 98-151 OBC Clk Adj fr 20.6 to 0.00 msec/day 36228 118/2304 98-152 HALOE Power OFF 36229 119/0039 98-153 MLS Power ON 36250 120/1115 98-154 HRDI HRDI to low power 36272 121/2136 98-155 OBC Clk Adj fr 0.00 to 20.6 msec/day _______________________________________________________________ APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 01 May 1998 MNEMONIC STATE DESCRIPTION ORBITS --------- ----- ------------ ------ HRPTSPBIMON Y-HI PTS Pulse Bus Current Monitor 36171,235,39 QTSISAI/F Y-HI SSPP Baseplate by SISA I/F 36176,89,203,204, 267-72 WIEUTEMP Y-LO WINDII EU Temperature 36220,22,26,27,29-35 NBRECBI Y-HI NBTR B Total Current 36224,39 HRPSEQBIMON Y-HI PSE Quiet Bus Current Monitor 36224,39,49,69,70 CDUNRG28 Y-LO +28V Unregulated Bus 36249 HRIFESURVTMP Y-HI IFE Survival Heater Temp 36253 HRRADTEMP Y-HI IFE Radiator Temperature 36253 The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS --------- ------------ ------ None this report period APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 01 May 1998 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ---- ----------------- 36180 115/17:42 (25 Apr 98) from 00.0 to 20.6 msec/day 36209 117/16:50 (27 Apr 98) from 20.6 to 00.0 msec/day 36272 121/21:46 (01 May 98) from 00.0 to 20.6 msec/day _______________________________________________________________ APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 01 May 1998 25 Apr 1998 - GMT Day 115 Beta = 36.9 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 +728.0/+728.0 -3.05/-4.31 +0.0/ +0.0 18.4 0.000 0.0 2 +56.0/ -11.2 +6.44/+4.51 +29.6/-16.0 25.0 1.022 22.4 3 +123.0/ +0.0 +5.15/+3.23 +28.8/-16.0 24.8 1.024 21.9 01 May 1998 - GMT Day 121 Beta = 17.3 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 +728.0/+728.0 -2.73/-3.99 +0.0/ +0.0 18.4 0.000 0.0 2 +39.2/ -5.6 +7.09/+5.47 +32.0/-15.6 24.2 1.019 23.8 3 +44.8/ -5.6 +5.79/+4.51 +30.4/-16.0 24.2 1.021 23.0 V/T LEVEL CHANGES ORB# TIME LVL FR-TO ----- -------- ---------- no changes APPENDIX E UARS ANOMALY REPORTS Week ending 01 May 1998 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 98-022 FOT 36272 121/2136 N/A TAC #2 Crashed ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 98-015 FOT April 1998 14170 GENERIC LATE ACQ 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 ------ ------ ----- ---- --- ----------------- 98-021 Generic Late Acq for May 1998 (Open until 31 May 1998). _______________________________________________________________ APPENDIX F UARS INSTRUMENT OPERATIONS SUMMARY Week ending 01 May 1998 INSTRUMENT SUMMARY FOR MONTH OF April 1998 (hours) UNPLANNED UNSCHEDULED ON OFF OFF OFF (Insufficient (Other than Instrument (Actual) (Scheduled) Power) Power Problem) COMMENTS ---------- ------ ----------- ----------- ------------- ------------ ACRIM 598 122 0 0 HALOE 500 220 0 0 HRDI 391 316 13 0 MLS 236 484 0 0 PEM (axis) 0 720 0 0 PEM (zeps) 111 609 0 0 PEM (neps) 0 720 0 0 SOLSTICE 720 0 0 0 Note 1 SUSIM 587 133 0 0 WINDII 185 535 0 0 Note 1 - No star data March 15-19 Cold side of spacecraft was facing northward: 28.5 days Cold side of spacecraft was facing southward: 1.5 days SEVNTFW18