******************************************************************** UARS WEEKLY STATUS REPORT - 02 Oct 1998 ******************************************************************** *********** SOLSTICE *********** SOLSTICE continues to operate normally, collecting solar data on all available orbital tracking periods and stellar calibration observations, whenever possible. *********** SUSIM *********** SUSIM successfully gathered its normal solar, offset, and occulation data during this past week without apparent problems. We have asked that the version 7 SUSIM production software be promoted. Reprocessing to the new version (V20) will soon begin. *********** PEM *********** PEM was not active PEM is now conducting tests of the OBC activation. PEM activation occurs during daylight only, when there is adequate power generated from the UARS solar array. Currently, testing is half-way completed, and the PEM magnetometer and medium energy spectrometers can activate under OBC control. Tests are now being conducted on the high energy particle spectrometers. Initial tests of these units show failure to enable high voltage power. The PEM team is investigating this result. *********** HALOE *********** HALOE is presently off due to the yaw and is scheduled to power on beginning of day October 3. When HALOE was on it was operating within its nominal operating range. All science channels continue to provide excellent science data. *********** MLS *********** MLS is scheduled to begin operations on Oct 6 and operate though Oct 10. The MLS team will operate the instrument in a mode for diagnosing the reoccurance of slips in the antenna scan mechanism, and to attempt to find a method of operating the instrument which minimizes the impact of these slips on scientific data. *********** HRDI *********** HRDI started operating in the daytime-only mode on September 30th. We are currently evaluating operations in this new configuration. *********** WINDII *********** WINDII is currently off, and is planned to be activated Oct. 5-11, 1998. *********** 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 attended a meeting involving possible impacts resulting from the scheduled chilled water outage on the weekend of October 10-11. Current plans do not include an interruption in service at the CDHF during this time period. 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. 60 days HAL (4.80) PROD (L1) (1873R-1560C-23F=290L) 24 days HAL (4.80) PROD (L3) (1873R-882C=991L) 85 days SOL (4.62) PROD (L2-L3) (2349R-1686C=663L) 1 days SEN (5.00) PROD (L0) (1R-1C=0L) The CDHF is scheduling the installation of IDL software version 5.1. This installation will satisfy Y2K requirements and is also recommended by RSI as a possible solution to a current PRINT routine problem reported by SOLSTICE. The CDHF maintains a matrix of installation status on all patches/upgrades required on the current UARS VMS cluster operating systems for Y2K compliance. CDHF pending software upgrades: SUSIM v7.0, IDL 5.1, OpenIngres *********** FOT *********** REPORTING PERIOD This report covers 19 September 1998 (Orbit 38370, GMT Day 262) through 25 September 1998 (Orbit 38474, GMT Day 268). 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 PEM 262/0708 38374 ZEPS Off PEM 262/0943 38376 AXIS On PEM 266/2129 38443 AXIS Off WINDII 267/0401 38447 Off HALOE 267/0921 38450 On SOLSTICE 267/1102 38451 On ACRIM 267/1102 38451 On SUSIM 267/1950 38457 On The beta angle ranged between 41.5 degrees to 17.1 degrees for this report period. The beta angle is now decreasing toward a minimum angle of -2.0 degrees for the yaw on 29 September 1998 (DOY 272). The new power monitor (PMON) flight software was successfully uplinked during orbits 38446, 38447, 38448, and 38449 (267/02:21, 267/04:01, 267/05:46, and 267/06:38 UTC). PMON control of heaters began during orbit 28450 (267/07:34 UTC). The upgraded version of PMON includes enhanced capabilities for Rday-onlyS heater control, used to minimize spacecraft power loading during the solar array eclipse period (approximately half of each orbit). The enhanced PMON software also includes the capability to support Rday-onlyS operation of instruments, in which they will be power cycled on when the solar array has excess power, and turned off during array eclipse periods. PMON currently can support three instruments for this mode of operation: PEM, HRDI, and SOLSTICE. Following the first orbit of the PMON software uplink, a low load bus voltage condition (23.2 V) resulted in automatic power shedding via the telemetry monitor (TMON) flight software. The SSPP instruments (SOLSTICE, ACRIM, and SUSIM), as well as the HALOE and WINDII instruments, were powered off as part of this load shedding. The low bus voltage resulted from the long duration of the first contact during solar array Rnight.S Pre-uplink simulations also showed low bus voltage for this contact (23.4 V), but not low enough to RtripS TMON and result in the load shedding which actually occurred. However, such fluctuations in bus voltage can result from minor orbital changes in other spacecraft loads, and therefore are tremendously difficult, if not impossible, to predict with certainty. Regardless, the TMON response was proper under the circumstances, and the SSPP and HALOE instruments were restored to full operation as soon as possible (WINDII was scheduled to be turned off the following day, so it was left powered off). Examination of PMON telemetry following the uplink showed it working as planned, with one exception. The WINDII heater load was not being properly controlled, due to a power switching unit (PSU) command conflict. PSU documentation indicates that PSU commands must be separated by at least one second, and the PMON command responses were designed accordingly. However, post-uplink examination of telemetry showed that the WINDII heater commands (which followed other PSU commands from PMON by one second) did not function. The FOT determined that one second separation of PSU commands was probably not adequate, so the PMON command responses were modified to ensure at least two seconds between each PSU command. These changes were uplinked on orbit 38473 (268/21:30 UTC), and all PMON PSU commands have functioned properly since that time. Two manually generated SSPP stellar offset experiments were performed on GMT days 265 and 267 at the request of SOLSTICE operations. 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 18 September 1998 and 25 September 1998 are provided in Appendix D. The clock error ranged from 10.2 to -11.7 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 = 03 The following real-time command sheets were executed for the listed operational element(s) during this report period (see Appendix A). % FOT 06 % ACRIM 01 % HALOE 01 % PEM 03 % SOLSTICE 01 % SUSIM 01 % WINDII 01 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. % FOT 04 Four (4) Anomaly Report remained OPEN at the end of this report period (see Appendix E). TRANSPONDER FREQUENCIES: Transponder A: 98/210 - 2287.496941 Transponder B: 98/211 - 2287.499161 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 98/267 show the observatory data loss to be 21 hours, 06 minutes, 52.340 seconds (an increase of 11.200 seconds since last report period). This is a 0.0344 percent data loss which equals a 99.9656 percent data capture for the mission. The increase of 11.200 seconds occurred over two days: 7 0.256 seconds on Day 266 due insufficient overlap, and 7 10.944 seconds on Day 267 due to insufficient overlap. The FOT created and configured a new CMS Spacecraft Characteristics and Parameters file to accommodate the operational change to a reduced size ATC memory. As of the PMON/Flight Software uplink on 24 September, the size of the stored command memory is now 768 commands (as compared to the previous size of 1024 commands). In addition, the FOT created several new Relative Time Sequences(s) (RTSs) which were also necessary to facilitate proper PMON commanding with the new flight software. A final dry run simulation of the new Power Monitor Software was completed on 23 September 1998. The operational packs, software and database version following the PMON software update are: PACK # GND S/W VER DATBASE VER COMMENT PE51 10.12 FOT 069 Prime PE03 10.12 FOT 069 Backup OTHER SIGNIFICANT EVENTS UARS SATELLITE OPERATIONS FOT continues to improve a power profile for UARS based on the current status of the Modular Power System. Investigation into possible impacts of the Leonid meteorite shower in November 1998 continues. FDF has supplied Leonid flux angles to both UARS Fixed Head Star Trackers (FHST). YEAR 2000 OPERABILITY SUPPORT UARS Test and Training Simulator (UTTS) - No change. User Planning System (UPS) - The FOT coordinated with the UPS development team lead to discuss the FOTUs and the CMS test teamUs TDRS contact needs for Year 2K testing. Several options for getting a Year 2K TDRS contact data to the CMS system were discussed. These options will be pursued early next week. Multi Satellite Operations Control Center (MSOCC) - Per an action item from last weekUs POCC/AP Year 2K status meeting, the FOT researched several questions given to them by the POCC/AP test team. The FOT is in the process of generating a memorandum containing answers to the test teamUs questions. At the request of the POCC test team, the FOT attempted to generate a sample Year 2K ATC load which included nothing but NOOP commands. The purpose of the sample load was to enable the POCC/AP test team to perform load acceptance testing on the AP. Unfortunately, the FOT and CMS test team was unable to successfully generate such a load. Both the FOT and the CMS test team are currently investigating the reason that the back-up CMS is failing during the load generation process involving a Year 2K load. Command Management System (CMS) - The FOT met with CMS software development team representative Tony Yan to discuss possible Year 2K related problems with the CMS software. Specifically, Year 2K testing found that the CMS does not correctly sort the AOT and LOT of targets in the SSPP Orbital Events file when the view period of the target crosses the 1999-to-2000 year boundary. However, this particular problem does not present an operational concern as the only SSPP target that is viewed during that portion of the day is the Sun, and the Sun is not actually in view of UARS during the 1999/2000 cross-over. Flight Dynamics Facility (FDF) - A partial coordinated data set was received at the end of this week but no testing has been attempted. OBC PMON FLIGHT SOFTWARE UPDATE Flight Software - Complete. Ground Support Software - Complete. Verification Testing - Complete. Uplink - Successfully completed on 24 September 1998. IP NETWORK TESTING Space Network (SN) - No change. Testing with the NCC 98 system to support routine flight operations is being planned. Deep Space Network (DSN) and Ground Spaceflight Tracking and Data Network (GSTDN) - Commanding with the JSC simulator (destination code problem) is being investigated. UARS PROPULSION MODULE B/D THRUSTER LINE FILL The B/D thruster refill effort continues. The Eaton Latch Valve test report is still being reviewed by the UARS FOT. UARS RE-ENGINEERING - TELEMETRY PROCESSING Flight operations is providing support to the re-engineering effort to process the UARS telemetry on the TOMS/EP control center computer system. The software performance continues to be evaluated. UARS COMMAND RE-HOST PHASE 1 DEMONSTRATION A phase 1 feasibility demonstration of the Lockheed Martin SCS-21 control center system was successfully conducted on 22 September 1998. The NCC-98 system was not available for the demonstration. Future development is waiting Rgo aheadS approval. MEETINGS The FOT attended a meeting on 24 September 1998 concerning the User Planning System (UPS) Y2K release and plans for verification testing. The next battery telecon is scheduled for 20 October 1998 at 1:00 pm. FUTURE SIGNIFICANT EVENTS The next UARS Yaw Around Maneuver is scheduled for scheduled for 29 September 1998. 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 25 September 1998 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------- 38374 262/0708 98-351 PEM ZEPS OFF 38376 262/0943 98-352 PEM AXIS ON 38402 264/0409 98-353 OBC Clk Adj fr 0.00 to 20.6 msec/day 38426 265/1755 98-354 OBC Clk Adj fr 20.6 to 0.00 msec/day 38443 266/2129 98-355 PEM Power Off AXIS 38447 267/0401 98-356 WINDII Power OFF 38448 267/0546 98-357 OBC Clear TMONS 38446 267/0221 98-358 OBC Load PMON Ver. 63 38450 267/0921 98-359 HALOE Power ON 38451 267/1102 98-360 SOLSTICE Power ON 38451 267/1102 98-361 ACRIM Power ON 38457 267/1950 98-362 SUSIM Power ON 38473 268/2130 98-363 OBC RTS Loads 38473 268/2130 98-364 OBC GENASCII - RTS _______________________________________________________________ APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 25 September 1998 MNEMONIC STATE DESCRIPTION ORBITS --------- ----- ------------ ------ HRPSEQBIMON Y-HI PSE Quiet Bus Current Mon 38434,35,41,65,70 NBRECBI Y-HI NBTR-B Current 38434,35,70 QTSISAIF Y-HI SSPP Baseplate by SISA I/F 38446 OBSVLBEON R-LO Load Bus Volts at EON 38447-49 OBSBATVEON2 Y-LO Battery 2 voltage at EON 38447-49 OBSBATVEON3 Y-LO Battery 3 voltage at EON 38447-49 OBSSOC2 R-LO Battery 2 Current SOC 38448-9 OBSSOC3 R-LO Battery 3 Current SOC 38448-9 WIPBVOLTAGE Y-LO Pulse Bus Voltage 38434,35 WIQBVOLTAGE Y-LO Quiet Bus Voltage 38441 WIFWTEMP Y-LO Filter Wheel Temp 38457-465,473 WIISUTEMP R-LO ISU Temp 38453-73 The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS --------- ------------ ------ WIISUTEMPRL ISU Temp Red Low 38455-8 WIFWTEMPRL Filter Temp Red Low 38456-7 WIISUTEMPRL WINDII ISU Temperature 38459-473 WIFWTEMPRL WINDII FW Temperature 38460,61,63 _______________________________________________________________ APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 25 September 1998 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ---- ----------------- 38402 264/04:15 (21 Sept 98) from 00.0 to 20.6 msec/day 38426 265/17:55 (22 Sept 98) from 20.6 to 00.0 msec/day _______________________________________________________________ APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 25 September 1998 18 Sept 1998 - GMT Day 261 Beta = 41.5 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 -3.30/-2.73 +0.0/ +0.0 18.1 0.000 0.0 2 +67.2/ 0.0 +5.71/+6.44 +28.8/-16.0 24.6 1.022 22.5 3 +33.6/-22.4 +4.77/+5.47 +28.4/-16.8 24.6 1.023 22.1 25 Sept 1998 - GMT Day 268 Beta = 17.1 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 18.1 0.000 0.0 2 +50.4/0.0 +6.76/+5.15 +31.6/-16.0 24.2 1.023 22.8 3 +33.6/-44.8 +5.47/+3.87 +30.4/-16.4 24.2 1.021 22.2 V/T LEVEL CHANGES ORB# TIME LVL FR-TO ----- -------- ---------- no changes (V/T 5) APPENDIX E UARS ANOMALY REPORTS Week ending 25 September 1998 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 98-061 FOT 38385 263/0030 20202 AP-7 Crashed 98-057 FOT 38413 264/2123 14170 Generic Late Acquisition 98-062 TMON 38447 267/0401 N/A TMONs NR-1 & NR-2 TRIPPED 98-063 FOT 38456 267/1840 N/A ATC Load Errors ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- None this report period 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 ------ ------ ----- ---- --- ----------------- 98-057 FOT Sept 98 See list 14170 GENERIC LATE ACQ 98-061 FOT 38385 263/00:30 20202 AP CRASH 98-062 FOT 38447 266/04:01 TMON 1 & 2 TRIP 98-063 FOT 38456 267/18:43 ATC LOAD ERRORS