******************************************************************** UARS WEEKLY STATUS REPORT - 29 AUGUST 2003 ******************************************************************** *********** SOLSTICE *********** For three days this week, SOLSTICE was powered and taking solar data only during daylight in support of the yaw maneuver. Otherwise, solar data were collected on all available orbital tracking periods. *********** SUSIM *********** SUSIM was turned off on Tuesday, Aug. 26. Otherwise, the experiment successfully gathered all of its daily mid resolution, weekly offset, and O2 occultation scans during periods of UARS telemetry or periods of onboard tape recording. *********** ACRIM *********** Nothing received. *********** PEM *********** Nothing received. *********** HALOE *********** Nothing received. *********** MLS *********** Nothing received. *********** HRDI *********** Nothing received. *********** WINDII *********** Nothing received. *********** MPG *********** The MPG continues to serve as the point-of-contact for UARS instrument operations in support of the Science Traceability Mission of UARS. On 27 August the MPG attended a meeting held to discuss problems, concerns, and tasks connected with modifying UARS spacecraft and ground systems so that UARS can relay data and telemtry through 3 TDRS spacecraft each orbit. Currently, UARS is limited by software constraints to the use of 2 TDRS spacecraft. Daily processing of instrument Daily Activity Plans continues with no problems. *********** CDHF *********** Nothing received. *********** FOT *********** REPORTING PERIOD This report covers 16 August 2003 (Orbit 65255, GMT Day 228) through 22 August 2003 (Orbit 65359, GMT Day 234). 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 230/2259 65299 POWER OFF PEM 234/2141 65358 POWER OFF AXIS 1 / ZEPS-NEPS The beta angle ranged between the angles of 37.0 degrees to 20.6 degrees for this report period. The beta angle is now decreasing towards a minimum angle of 0 degrees on 27 August 2003 (DOY 239). 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 23.6 V end-of-night (EON) load bus voltage. Battery temperatures are stable with a temperature delta between Battery 2 and Battery 3 of 1.28 to 1.29 degrees C. Additional battery performance data for each battery on 15 August and 22 August 2003 are provided in Appendix D. The clock error ranged from -12.1 to 10.1 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 = 00 ALERTS = 00 The following real-time command sheets were executed for the listed operational element(s) during this report period (see Appendix A). FOT = 05 WINDII = 01 PEM = 01 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. FOT = 02 Two (2) Anomaly Reports remained OPEN at the end of this report period (see Appendix E). GROUND SYSTEM OPERATION Two (2) operational support problems occurred this period. Anomaly Reports are included in Appendix E. The data loss calculations are no longer being supplied by Data Capture Facility (DCF). OTHER SIGNIFICANT EVENTS UARS SATELLITE OPERATIONS After several discussions with the Raytheon development team, the FOT was able to reproduce the error found in the Eclipse scripting executable (CECIL.exe). The error manifests itself in a slightly different manner on the UARS network than the ERBS network, so the FOT needed to determine that the same error was being seen on both systems. The patch has been tested on the prototype and will be released for operations early next week. On 15 August, the VT-6 charge level was utilized to support the WINDII turn on. The batteries were left in this charge rate until the 230/1421 event on 18 August 2003. Telemetry showed no signs that VT-6 was overcharging the batteries, but the FOT did not want to utilize this aggressive charge rate for longer than three days. After going back to VT-5 the end-of-night load bus voltage dropped all the way down to 23.8 V and WINDII was powered off on the 230/2259 event, to prevent an unsafe power condition. The future operations of WINDII will have to be reviewed by the FOT, UARS project scientist and the NASA power branch in order to come up with a viable solution. Fortunately, this turn on has at least provided some good data with which to make that decision. MEETINGS The FOT attended the biweekly UARS DRB meeting to review open Eclipse DRs. FUTURE SIGNIFICANT EVENTS The next UARS Yaw slew is scheduled for 27 August 2003 (DOY 239). This maneuver will be a Reverse to Forward Flight maneuver (Southern Hemisphere viewing). Attachments: Appendix A, Real-time Command 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 22 August 2003 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------ 65282 229/1928 03-213 OBC/CLK CLK ADJ FR 0.0 TO 20.6 MSEC/DAY 65294 230/1503 03-214 MPS VT6 TO VT5 & RESET SOC 65298 230/2126 03-215 OBC/CLK CLK ADJ FR 20.6 TO 0.0 MSEC/DAY 65299 230/2259 03-216 WINDII POWER OFF 65303 231/0622 03-217 OBC/CLK CLK ADJ FR 0.0 TO -20.6 MSEC/DAY 65320 232/0908 03-218 OBC/CLK CLK ADJ FR -20.6 TO 0.0 MSEC/DAY 65358 234/2141 03-219 PEM POWER OFF AXIS 1 / ZEPS-NEPS APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 22 August 2003 The following Out-Of-Limits occurrences were detected: MNEMONIC STATE DESCRIPTION ORBITS -------- ----- ----------- ------ -None this report period. The following ALERT occurrences were detected: MNEMONIC DESCRIPTION ORBITS -------- ----------- ------ -None this report period. APPENDIX C CLOCK & SOLAR ARRAY RATE CORRECTIONS Week ending 22 August 2003 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ----- ----------------- 65282 229/1928 CLK ADJ FR 0.0 TO 20.6 MSEC/DAY 65298 230/2126 CLK ADJ FR 20.6 TO 0.0 MSEC/DAY 65303 231/0622 CLK ADJ FR 0.0 TO -20.6 MSEC/DAY 65320 232/0910 CLK ADJ FR -20.6 TO 0.0 MSEC/DAY APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 22 August 2003 15 August 2003 - GMT Day 227 Beta = 38.8 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 -700.0/-700.0 -2.42/-4.31 +00.0/-50.0 07.2 0.000 0.0 2 +11.2/-72.8 +7.09/+4.19 +26.8/-50.0 25.4 1.040 23.0 3 +22.4/-67.2 +5.79/+3.23 +26.4/-50.0 25.4 1.040 22.5 22 August 2003 - GMT Day 234 Beta = 20.6 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 -700.0/-700.0 -3.05/-3.99 +00.0/+00.0 07.2 0.000 0.0 2 +33.6/-16.8 +6.44/+5.15 +28.8/-14.4 23.8 1.030 21.2 3 +22.4/-50.4 +5.15/+3.87 +28.0/-14.4 23.8 1.020 21.0 V/T LEVEL CHANGES ORB# AOS TIME LVL FR-TO ----- -------- --------- 65294 230/1503 LV6 -> LV5 APPENDIX E UARS ANOMALY REPORTS Week ending 22 August 2003 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 03-037 FOT 65336 233/0949 30832 Generic Late Acquisition 03-044 FOT 65347 234/0433 33557 33 sec Data Dropout ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 03-042 TDW 65186 223/1109 33437 TDW Could not support 03-043 FOT 65238 226/2119 N/A Excessive Data Dropouts ANOMALY INVESTIGATION REPORTS GENERATED AIR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- -None this report period. OPEN ANOMALY REPORTS AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 03-037 FOT See List August 03 30832 Generic Late Acquisition 03-044 FOT 65347 234/0433 33557 33 sec Data Dropout