******************************************************************** UARS WEEKLY STATUS REPORT - 16 May 2003 ******************************************************************** *********** SOLSTICE *********** SOLSTICE continues to perform nominally, taking solar data on all available orbital tracking periods. *********** SUSIM *********** SUSIM was powered off on May 14 for the yaw-around. Otherwise, it successfully gathered all of its daily mid resolution, weekly offset, and O2 occultation scans this past week during periods of UARS telemetry or tape recording. *********** ACRIM *********** Nothing received. *********** PEM *********** The PEM web site has moved. It has a new URL. Access the PEM web site using http://wwwpem.space.swri.edu. The PEM data from the GUVI conjunction periods has moved to http://wwwpem.space.swri.edu/guvi-pem.html. Level 2 PEM HEPSA data files are being reprocessed for submission to the DAAC. This data has been designated as version 2; however, there is no format difference from the version 1 data format. Version 2 HEPSA data is being generated because it was discovered that there exists processing errors within some of the HEPSA version 1 data files. Thus, if you are using any HEPSA version 1 data files from the DAAC, please replace them with the version 2 data files. Currently, HEPSA data between 1991274 and 2001365 has been reprocessed and archived at the GSFC DAAC. SwRI is working on reprocessing data PEM for 2002. PEM continues to work with the GUVI team on the diagnosis of data from the first conjunction period. Analysis of the two conjunction passes showed that the aurora as detected by GUVI was at higher latitude than UARS. GUVI images from other times from the first conjunction period show spatial regions that both GUVI and PEM sampled when aurora was present. Separation is several minutes to 10's of minutes when both instruments saw aurora. PEM has seen no aurora during the second conjunction period. Due to a spacecraft anomaly, no PEM data was collected during the third conjunction period. PEM continues to receive NMC data files from NOAA. No problems have been encountered. NOAA has changed the binary structure of the NMC data and PEM is now receiving two data streams, one in the original VAX format and the other from their new binary format. *Beginning of power orbit day (PEM activation): array current >5 amps, array voltage >53.5 volts, and battery current >2.0 amps. End of power orbit day (PEM deactivation): time in power orbit day >4 minutes, array current <9 amps, and battery currents <0.2 amps. Power orbit day variation: ~39-40 min at yaw to ~50-51 min at maximum beta. *********** HALOE *********** HALOE continues to perform successfully during scheduled operational periods. All engineering parameters are within nominal limits and the science data products are reasonable. Science data processing continues but is occasional affected by "clipped" events that result in missed events or require special processing to recover the events. New software is being added to evaluate each 24 hour file to check for problems in the file, such as "time jumps" in the data, so that appropriate processing can be used and responsible level 0 individuals at UARS can be alerted. The AIX IBM computer system that generates the plots and netcdf files for the HALOE web site has failed and we are in the process of getting it back in operation. Since it is an old system we are also investigating alternate solutions. *********** 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. Daily processing of instrument Daily Activity Plans continues with no problems. *********** CDHF *********** Nothing received. *********** FOT *********** REPORTING PERIOD This report covers 03 May 2003 (Orbit 63676, GMT Day 123) through 09 May 2003 (Orbit 62781, GMT Day 129). 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 HALOE 123/1158 63684 POWER ON WINDII 128/1004 63757 POWER OFF The beta angle ranged between the angles of 49.9 degrees to 28.0 degrees for this report period. The beta angle is now decreasing towards a minimum angle of 0 degrees on 16 May 2003 (DOY 136). 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 1.27 to 1.28 degrees C. Additional battery performance data for each battery on 02 May and 09 May 2003 are provided in Appendix D. The clock error ranged from -11.0 to 10.0 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 = 02 HALOE = 01 WINDII = 01 UARS Anomaly Reports initiated during this report period are listed in Appendix E and summarized below. FOT = 06 Six (6) Anomaly Reports remained OPEN at the end of this report period (see Appendix E). GROUND SYSTEM OPERATION Six (6) 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 This week the FOT worked with the Raytheon development team to try resolve the problems seen in the preliminary build. The FOT believes that all of the wait statement issues have been resolved, but will await testing of the official build to confirm that this code works properly. The status buffer display has been modified as well, with the only outstanding issue being the Eclipse time field. The development team has a handle on this problem and feels that it will be resolved soon. This functionality will also be tested when the official build arrives. The FOT also spoke with Anisa Ahmad of the NASA Power Branch, regarding the duration of the VT-6 mode following the next UARS yaw maneuver on 16 May 2003. This issue was raised due to the relatively sluggish recovery after the last yaw maneuver on 06 April 2003. Past analysis of the power data has shown the summer yaw maneuvers have a longer post-maneuver recovery time. It was recommended, due to this fact, that after the upcoming yaw the batteries should be kept in VT-6 until telemetry indicates it should be removed, but no longer than 3 days. This recommendation will be implemented pending NASA Mission Directors approval. MEETINGS The FOT attended the UARS monthly on 06 May 2003, to report spacecraft and operations status for the month of April. The FOT also attended the weekly UARS DRB on 06 May 2003, to review the open DRs and discuss the details of the next Eclipse software delivery. FUTURE SIGNIFICANT EVENTS The next UARS Yaw slew is scheduled for 16 May 2003 (DOY 136). This maneuver will be a Forward to Reverse 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 09 May 2003 ORBIT AOS NO. SUBSYS REASON ----- --- --- ------ ------ 63684 123/1158 03-105 HALOE POWER ON 63709 125/0600 03-106 OBC/CLK CLK ADJ FR 0.0 TO 20.6 MSEC/DAY 63728 126/1151 03-107 OBC/CLK CLK ADJ FR 20.6 TO 0.0 MSEC/DAY 63757 128/1004 03-108 WINDII POWER OFF (S/C LOW PWR) APPENDIX B OUT-OF-LIMITS & ALERTS OCCURRENCES Week ending 09 May 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 09 May 2003 CLOCK DRIFT RATE ADJUSTMENTS ORBIT TIME CLOCK RATE CHANGE ----- ----- ----------------- 63709 125/0602 CLK ADJ FR 0.0 TO 20.6 MSEC/DAY 63728 126/1158 CLK ADJ FR 20.6 TO 0.0 MSEC/DAY APPENDIX D UARS BATTERY PERFORMANCE DATA Week ending 09 May 2003 02 May 2003 - GMT Day 122 Beta = 55.8 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 -235.2/-263.2 -3.68/-4.94 +00.0/+00.0 08.3 0.000 0.0 2 +05.6/-67.2 +3.87/+2.92 +23.2/-15.2 25.8 1.030 18.8 3 +16.8/-44.8 +2.92/+1.97 +22.4/-14.4 25.6 1.020 18.4 09 May 2003 - GMT Day 129 Beta = 28.0 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/-4.62 +00.0/+00.0 07.7 0.000 0.0 2 +11.2/-78.4 +5.15/+3.87 +28.4/-15.2 23.8 1.040 20.2 3 +22.4/-72.8 +3.87/+2.60 +27.2/-15.2 23.8 1.030 19.9 V/T LEVEL CHANGES ORB# AOS TIME LVL FR-TO ----- -------- --------- -None this report period. APPENDIX E UARS ANOMALY REPORTS Week ending 09 May 2003 NEW ANOMALY REPORTS GENERATED AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- 03-019 FOT 63727 126/1008 N/A SEC Eclipse (PBK Problem) 03-020 FOT 63732 126/1334 32470 DROPOUTS ON I CHANNEL 03-018 FOT 63732 126/1757 30832 Generic Late Acquisition 03-021 FOT 63733 126/1943 32743 Late Acq 15 min recoverable 03-022 FOT 63742 127/0929 N/A PBK PROBLEM(REF 03-019) 03-023 FOT 63773 129/1105 32761 MULTIPLE DATA DROPOUTS ANOMALY CLOSURE INFORMATION RECEIVED AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS ------ ------ ----- ---- --- ----------------- -None this report period. 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 ------ ------ ----- ---- --- ----------------- 03-018 FOT See List May 03 30832 Generic Late Acquisition 03-019 FOT 63727 126/1008 N/A SEC Eclipse (PBK Problem) 03-020 FOT 63732 126/1334 32470 DROPOUTS ON I CHANNEL 03-021 FOT 63733 126/1943 32743 Late Acq 15 min recoverable 03-022 FOT 63742 127/0929 N/A PBK PROBLEM(REF 03-019) 03-023 FOT 63773 129/1105 32761 MULTIPLE DATA DROPOUTS