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UARS WEEKLY STATUS REPORT - 16 May 2003
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SOLSTICE
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SOLSTICE continues to perform nominally, taking solar data on all
available orbital tracking periods.
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SUSIM
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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.
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ACRIM
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Nothing received.
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PEM
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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.
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HALOE
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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.
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MLS
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Nothing received.
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HRDI
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Nothing received.
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WINDII
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Nothing received.
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MPG
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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.
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CDHF
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Nothing received.
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FOT
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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