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UARS WEEKLY STATUS REPORT - 05 September 2003
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SOLSTICE
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SOLSTICE continues to perform nominally, taking solar data on all
available orbital tracking periods. This week we received about 50% of
each day's data amounting to about 350 minutes of solar observing time
per day.
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SUSIM
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Nothing received.
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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 2002149 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 23 August 2003 (Orbit 65359, GMT Day 235) through
29 August 2003 (Orbit 65464, GMT Day 241).
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 235/0528 65363 POWER OFF
SUSIM 237/2241 65404 POWER OFF
SOLSTICE 237/2241 65404 FULLTIME TO DAY-ONLY
SOLSTICE 241/1251 65458 DAY-ONLY TO FULLTIME
SUSIM 241/1336 65458 POWER ON
A Reverse-to-Forward Yaw Around maneuver (number 122) was successfully
executed in Orbit 65431 beginning 239/18:25:30Z and completing at
239/19:02:40Z on 27 August 2003. All instruments were in their off or
standby mode (except for SOLSTICE in day-only). Due to the SA
position at 269 degrees, the effective night length of the spacecraft
after the maneuver was approximately 55.98 minutes. Post maneuver
analysis of data indicate that during the Yaw Around, the end-of-night
load bus voltage was 26.08 volts and the average depths of discharge
(DODs) on Batteries 2 and 3 were approximately 20.86 and 20.39 percent
respectively. The next (forward-to-reverse) YAW is scheduled for 03
October 2003 (DOY 276).
The beta angle ranged between the angles of 17.1 degrees to 06.9
degrees for this report period. The beta angle is now increasing
towards a maximum angle of 60 degrees on 15 September 2003 (DOY 258).
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 0.96 degrees C. Additional
battery performance data for each battery on 22 August and 29 August
2003 are provided in Appendix D.
The clock error ranged from -10.1 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 = 03
HALOE = 01
SUSIM = 02
SOLSTICE = 02
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 01
Two (2) Anomaly Reports remained OPEN at the end of this report period
(see Appendix E).
GROUND SYSTEM OPERATION
One (1) operational support problem 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
The patch to the Eclipse scripting executable (CECIL.exe) was
installed on the operational servers on 28 August 2003. This was done
to correct for the error found in certain IF and WAIT statement
combinations. Since the installation, no occurrences of the problem
have been seen.
MEETINGS
The FOT attended the UARS Three TDRS Meeting to discuss the steps
needed to utilize a third TDRS. The first steps to be done are to get
the backup CMS in working order and to take another look at the actual
benefit, in terms of additional coverage, this patch would provide. A
follow up meeting is scheduled for Sept 10th, at which a decision to
proceed will be made.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for 03 October 2003 (DOY 276).
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 29 August 2003
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
65363 235/0528 03-220 HALOE POWER OFF
65403 237/2100 03-221 OBC/CLK CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
65404 237/2241 03-222 SUSIM POWER OFF
65404 237/2241 03-223 SOLSTICE FULLTIME TO DAY-ONLY OPS
65417 238/1949 03-224 MPS VT LEVEL 6 (YAW)
65422 239/0336 03-225 OBC/CLK CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
65431 239/1755 03-224 MACS YAW REV TO FWD
65432 239/1858 03-224 MACS YAW REV TO FWD (COMPLETE)
65457 241/1155 03-224 MPS VT LEVEL 5 (YAW)
65458 241/1251 03-226 SOLSTICE FROM DAY-ONLY TO FULLTIME
65458 241/1336 03-227 SUSIM POWER ON (BEGIN)
65459 241/1418 03-227 SUSIM POWER ON (TIME CMDS)
65462 241/1744 03-224 MPS BASETAB BATSOC (YAW)
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 29 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 29 August 2003
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
65403 237/2100 CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
65422 239/0346 CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 29 August 2003
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
29 August 2003 - GMT Day 241 Beta = 06.9 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/-50.0 07.2 0.000 0.0
2 +11.2/-44.8 +5.47/+4.51 +28.0/-50.0 25.1 0.970 20.6
3 +22.4/-67.2 +4.19/+3.23 +27.2/-50.0 25.0 0.970 20.3
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
65417 238/1949 LV5 -> LV6
65457 241/1155 LV6 -> LV5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 29 August 2003
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
03-045 FOT 65382 236/1124 N/A Telemetry hits/load abort
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
03-044 FOT 65347 234/0433 33557 33 sec Data Dropout
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
03-045 FOT 65382 236/1124 N/A Telemetry hits/load abort