******************************************************************** UARS WEEKLY STATUS REPORT - 03 AUG 2001 ******************************************************************** *********** SOLSTICE *********** SOLSTICE continues to operate normally, taking solar data on all available orbital tracking periods and stellar calibration observations whenever possible. We continue to gather enough data to meet all the SOLSTICE science objectives during this period of reduced tape recorder operations. *********** SUSIM *********** Thanks a generous donation of power by PEM, we were able to plan for nearly all of our final (?) lamp calibration. We are most grateful. The sequence of corresponding reference channel solar scans begins today. SUSIM has completed its daily solar scans this past week during periods of predicted UARS telemetry. *********** ACRIM *********** Nothing received. *********** PEM *********** Nothing received. *********** HALOE *********** Nothing received. *********** MLS *********** Nothing received. *********** HRDI *********** Nothing received. *********** WINDII *********** Nothing received. *********** MPG *********** MPG distributed a revised copy of the Instrument Schedule for the next yaw period. On 01 August the MPG participated in the UARS Monthly Status Review meeting. Daily processing of instrument Daily Activity Plans continues with no problems. *********** CDHF *********** Nothing received. *********** FOT *********** REPORTING PERIOD This report covers 21 July 2001 (Orbit 53896, GMT Day 202) through 27 July 2001 (Orbit 54000, GMT Day 208). 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 PEM 202/0746 53900 Power Off PEM 202/0929 53901 Day Only PEM 202/1526 53905 Full Time PEM 202/1849 53907 Day Only PEM 202/2029 53908 Power Off PEM 202/2350 53910 Day Only HALOE 208/0004 53986 Power On PEM 208/0610 53898 AXIS On The beta angle ranged between the angles of 75.7 degrees to 54.1 degrees for this report period. The beta angle is now decreasing towards a minimum angle of 0 degrees on 09 August 2001 (DOY 221). 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 1.2 to 1.3 degrees C. Additional battery performance data for each battery on 20 July 2001 and 27 July 2001 are provided in Appendix D. The clock error ranged from Ð11.3 to 6.3 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. ¥ OUT-OF-LIMITS = 02 ¥ ALERTS = 00 The following real-time command sheets were executed for the listed operational element(s) during this report period (see Appendix A). ¥ FOT = 04 ¥ HALOE = 01 ¥ PEM = 09 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. ¥ FOT = 01 One (1) Anomaly Report remained OPEN at the end of this report period (see Appendix E). TRANSPONDER FREQUENCIES: · Transponder A: 00/316 - 2287.496493 · Transponder B: 01/119 - 2287.499116 GROUND SYSTEM OPERATION One (1) 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 01/207 show the observatory data loss to be 302 hours, 55 minutes, 48.256 seconds. This shows a loss of 06 minutes and 13.088 seconds since the last report period. This is a 0.39 percent data loss, which equals a 99.61 percent data capture for the mission. The increase of 06 minutes and 13.088 seconds occurred over five (5) days: · 35.168 seconds on Day 202 due to a Data Hit. · 1 minute and 16.256 seconds on Day 204 due to Data Hits · 4 minutes and 08.000 seconds on Day 205 due to bad weather TTR# 23977 · 13.664 seconds on Day 207 due to a Data Hit OTHER SIGNIFICANT EVENTS UARS SATELLITE OPERATIONS The UARS FOT attended a UARS All-Hands Meeting on Wednesday, July 25,2001. At this meeting the FOT and all UARS entities were informed that NASA headquarters has stated (verbally) that there will be no funds available to operate UARS past this September. This statement is unofficial at this time, but the FOT has begun work on the decommissioning plan, which will end all UARS operations. All development activities will be continued until this decision is finalized; however, they may be discontinued pending the outcome from NASA headquarters. The FOT changed the safehold configuration on board this week. The previous configuration had been sun-pointing safehold, which only gave a few orbits of time before the batteries would suffer severe overcharging and most likely end the mission. The current configuration is now earth-pointing safehold with the earth sensor off. This will allow the spacecraft to keep pitching over at one revolution per orbit and keep the other axis stable for a minimum of 3-4 orbits. Given the almost realtime status of UARS operations this should give enough time to react to a safehold situation. MEETINGS The UARS FOT attended a UARS All-Hands Meeting on Wednesday, July 25,2001. The UARS FOT attended a UARS SERB/TAC RS Meeting on Wednesday, July 25,2001. The UARS FOT attended a Safehold Working Group Meeting on Thursday, July 26, 2001. FUTURE SIGNIFICANT EVENTS The next UARS Yaw slew is scheduled for 08 August 2001 (DOY 220). This maneuver will be a Forward to Reverse Flight maneuver (Southern Hemisphere viewing). 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 27 July 2001 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------ 53900 202/0746 01-465 PEM (Z/H) Power OFF 53901 202/0929 01-466 PEM (Z/H) Power ON DAY ONLY 53905 202/1526 01-467 PEM (Z/H) Power ON FULL TIME 53907 202/1849 01-468 PEM (Z/H) Power ON DAY ONLY 53908 202/2029 01-469 PEM (Z/H) Power OFF 53910 202/2350 01-470 PEM (Z/H) Power ON DAY ONLY 53911 203/0106 01-471 PEM (Z/H) TO FULL TIME OPS 53924 203/2132 01-472 OBC/CLK Clk Adj from 4.20 to 20.6 msec/day 53980 207/1449 01-473 MACS Safehold Reconfig 53982 207/1809 01-474 NBTR NOOPS D-208 53986 208/0004 01-475 PEM ZEPS HEPS TO DAY ONLY 53986 208/0004 01-476 HALOE Power ON 53898 208/0610 01-477 PEM Power ON AXIS 53997 208/1810 01-478 NBTR D209 noops ______________________________________________________________________________ APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 27 July 2001 The following Out-Of-Limits occurrences were detected: MNEMONIC STATE DESCRIPTION ORBITS -------- ----- ----------- ------ CDUNRG28 Y-LO CDH UNREGULATED 28V 53900 HRPSEQBIMON Y-HI HRDI QB CURRENT MONITOR 53899,900 The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS -------- ----------- ------ -None this report period _______________________________________________________________________________ APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 27 July 2001 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ----- ----------------- 53924 203/2132 Clk Adj from 4.20 to 20.6 msec/day _______________________________________________________________________________ APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 27 July 2001 20 July 2001 - GMT Day 201 Beta = 77.4 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 +728.0/+728.0 -1.79/-3.05 +0.0/+0.0 12.2 0.000 0.0 2 +11.2/-89.6 +2.60/+1.34 +14.4/-15.2 31.5 0.096 13.3 3 +16.8/-44.8 +1.97/+1.03 +14.0/-15.6 31.5 0.095 13.3 27 July 2001 - GMT Day 208 Beta = 54.1 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 -3.68/-4.94 +0.0/+0.0 12.0 0.000 0.0 2 +11.2/-67.2 +4.51/+3.23 +24.8/-15.2 25.0 1.050 17.9 3 +22.4/-44.8 +3.55/+2.29 +24.0/-14.4 24.8 1.050 17.0 V/T LEVEL CHANGES ORB# TIME LVL FR-TO ----- ---- --------- -no changes V/T 5 ______________________________________________________________________________ APPENDIX E UARS ANOMALY REPORTS Week ending 27 July 2001 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 01-044 FOT 53941 205/0004 23997 Late Acq. due to weather at W.S. ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 01-044 FOT 53941 205/0004 23997 Late Acq. due to weather at W.S. 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 ------ ------ ----- ---- --- ----------------- 01-041 FOT see list July 01 14170 Generic Late Acquisition SEVNTFW01/30