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UARS WEEKLY STATUS REPORT - 08 August 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 60% of
each day's data amounting to about 500 minutes of solar observing time
per day.
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SUSIM
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SUSIM 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.
A special high (0.15 nm) resolution scan for 115-200 nm is planned
for early on Wednesday, August 13 to roughly coincide with the
launch (about 7 hours earlier) of the U. Colorado EUV rocket. We do
this on the next day to avoid the uncertain solar open-loop pointing
that is scheduled for Tuesdays.
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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 2002119 has been
reprocessed and archived at the GSFC DAAC. HEPSA data files from 2002120
through 2002129 are processed and awaiting archiving at the 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 26 July 2003 (Orbit 64939, GMT Day 207) through 01
August 2003 (Orbit 65043, GMT Day 213).
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
SOLSTICE 209/1404 64977 DAY-ONLY TO FULLTIME OPS
SUSIM 210/1542 64994 POWER ON (PART 1)
HALOE 212/1356 65022 POWER ON (WARMUP)
A Forward-to-Reverse Yaw Around maneuver (number 121) was successfully
executed in Orbit 64949 beginning 207/16:27:01Z and completing at
207/17:04:11Z on 26 July 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 57.24 minutes. Post maneuver
analysis of data indicate that during the Yaw Around, the end-of-night
load bus voltage was 25.20 volts and the average depths of discharge
(DODs) on Batteries 2 and 3 were approximately 22.10 and 21.90 percent
respectively. The next (reverse-to-forward) YAW is scheduled for 27
August 2003 (DOY 239).
The beta angle ranged between the angles of 02.2 degrees to 22.5
degrees for this report period. The beta angle is now increasing
towards a maximum angle of 42 degrees on 11 August 2003 (DOY 223).
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 1.28to 1.61 degrees C. Additional
battery performance data for each battery on 25 July and 01 August
2003 are provided in Appendix D.
The clock error ranged from -10.2 to 09.6 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
SOLSTICE = 01
SUSIM = 01
HALOE = 02
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 01
One (1) Anomaly Report remained OPEN at the end of this report period
(see Appendix E).
GROUND SYSTEM OPERATION
One (1) 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
The FOT reviewed the data from the yaw on 26 July 2003 with the NASA
Power Branch representative Anisa Ahmad. It was noticed that the
differential voltage on both batteries was increasing several orbits
prior to the yaw. In order to help minimize this it was suggested
that the batteries be put into VT-6 a half or full day before the yaw
event. This suggestion will be brought up at the monthly status
review on 5 August 2003 and any implementation will require approval
from the Mission Director.
MEETINGS
-None this report period
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 01 August 2003
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
64948 207/1456 03-195 MACS YAW - FWD TO REV
64948 207/1535 03-195 MACS YAW - FWD TO REV
64949 207/1702 03-195 MACS YAW - FWD TO REV
64967 208/2102 03-196 OBC CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
64977 209/1404 03-197 SOLSTICE DAY-ONLY TO FULLTIME OPS
64978 209/1504 03-195 MPS VT LEVEL 5
64981 209/1915 03-195 MPS BATSOC
64985 210/0202 03-198 OBC CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
64994 210/1542 03-199 SUSIM POWER ON (PART 1)
65006 211/1134 03-199 SUSIM POWER ON (COMPLETE)
65022 212/1356 03-200 HALOE POWER ON (WARMUP)
65025 212/1724 03-201 HALOE POWER ON (COMPLETE)
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 01 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 01 August 2003
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
64967 208/2102 CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
64985 210/0205 CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 01 August 2003
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
01 August 2003 - GMT Day 213 Beta = 22.5 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/ 07.2 0.000 0.0
2 +00.0/-123.2 +6.44/+4.83 +28.8/-15.2 24.3 1.030 20.9
3 +22.4/-50.4 +5.15/+3.87 +28.0/-15.2 24.2 1.020 20.6
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
64948 207/1456 LV5 -> LV6
64978 209/1404 LV6 -> LV5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 01 August 2003
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
03-037 FOT 65040 213/1722 30832 Generic Late Acquisition
ANOMALY CLOSURE INFORMATION RECEIVED
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.
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