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UARS WEEKLY STATUS REPORT - 01 AUG 2003
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SOLSTICE
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For four days this week (205-209), SOLSTICE was powered only during
daylight to support the yaw maneuver. Otherwise, solar data were
collected on all available orbital tracking periods. In general, we get
about 50% of the day's data returned from the spacecraft. This amounts
to about 450 minutes of solar data per day nominally and about 250
minutes per day during daytime only ops.
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SUSIM
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SUSIM took no data for 25-28 of July because of the power restrictions
during the yaw-around. Otherwise, the instrument 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.
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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 2002099 has been
reprocessed and archived at the GSFC DAAC.
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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Nothing received.
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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 19 July 2003 (Orbit 64833, GMT Day 200) through 25
July 2003 (Orbit 64938, GMT Day 206).
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 203/0823 64884 POWER OFF
SOLSTICE 205/2017 64921 POWER OFF
PEM 205/2052 64922 POWER OFF
SUSIM 205/2052 64922 POWER OFF
The beta angle ranged between the angles of 29.8 degrees to 06.3
degrees for this report period. The beta angle is now decreasing
towards a minimum angle of 0 degrees on 26 July 2003 (DOY 207).
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 0.95 to 1.28 degrees C. Additional
battery performance data for each battery on 18 July and 25 July 2003
are provided in Appendix D.
The clock error ranged from -09.7 to 10.3 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 = 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 = 04
HALOE = 01
SOLSTICE = 01
PEM = 01
SUSIM = 01
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 03
Three (3) Anomaly Report remained OPEN at the end of this report
period (see Appendix E).
GROUND SYSTEM OPERATION
Three (3) 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
On the 203/1726-1755 TDRS East event the UARS POCC failed to acquire
data and WSC showed no RF. This was caused by an operator error of
failing to uplink the days stored command load. Without the new load
the stored command processor onboard halted. This caused the negative
acquisition on the subsequent pass because the HGA slew commands were
not sent out of the stored command area of memory. On the following
203/1836-1902 pass the stored command load was uplinked and the
pointer was jumped to the proper location. The only impact to
operations was a loss of a single sun track, which was approximately
12.5 minutes in duration (203/18:49:24-19:02:00). This error occurred
by not following standard operating procedure, and the FOT has been
reminded of the importance of strict adherence to this procedure.
MEETINGS
The FOT attended the UARS/ERBS DR meeting to discuss the status of
open DRs and future plans. It was decided at this meeting that this
meeting will become a biweekly meeting, due to the lack of high
severity DRs
The FOT also attended an informal review of the operator error on 24
July 2003.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for 26 July 2003 (DOY 207). This
maneuver will be a Forward to Reverse Flight maneuver (Northern
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 25 July 2003
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
64884 203/0823 03-187 HALOE POWER OFF (YAW) LOW POWER
64889 203/1649 03-188 OBC/CLK CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
64890 203/1836 03-189 OBC ATC JUMP LOCATION 508
64891 203/1911 03-190 OBC ATC NOOPS
64907 204/2200 03-191 OBC/CLK CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
64921 205/2017 03-192 SOLSTICE FULLTIME TO DAY ONLY
64922 205/2052 03-193 PEM POWER OFF
64922 205/2052 03-194 SUSIM POWER OFF
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 25 July 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 25 July 2003
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
64884 203/0823 CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
64907 204/2200 CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 25 July 2003
18 July 2003 - GMT Day 199 Beta = 34.1 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 -700.0/-700.0 -3.05/-4.31 +00.0/-00.0 07.2 0.000 0.0
2 +11.2/-112.0 +5.15/+3.87 +27.2/-16.0 24.2 1.030 19.8
3 +22.4/-44.8 +3.87/+2.92 +26.8/-16.0 24.2 1.020 19.5
25 July 2003 - GMT Day 206 Beta = 06.3 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 -3.68/-4.94 +00.0/-00.0 07.2 0.000 0.0
2 +11.2/-134.4 +4.83/+3.55 +27.2/-12.8 24.5 1.000 19.7
3 +22.4/-44.8 +3.55/+2.60 +26.4/-12.8 24.5 1.000 19.2
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
-None this report period.
APPENDIX E
UARS ANOMALY REPORTS
Week ending 25 July 2003
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
03-035 FOT 64889 203/1726 N/A ATC HALT
03-031 FOT 64913 205/0634 30832 Generic Late Acquisition
03-036 FOT 64935 206/1831 N/A Lost Lock - White S. Maint.
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
03-034 FOT 64804 198/0139 N/A SSPP IN WRONG OPSTATE
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
------ ------ ----- ---- --- -----------------
03-031 FOT See List July 03 30832 Generic Late Acquisition
03-035 FOT 64889 203/1726 N/A ATC HALT
03-036 FOT 64935 206/1831 N/A Lost Lock - White S. Maint.