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UARS WEEKLY STATUS REPORT - 06 Dec 2002
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SOLSTICE
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Other than being off for the solar eclipse this week, SOLSTICE continues
to operate normally, taking solar data on all available orbital tracking
periods.
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SUSIM
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After resuming operations on Monday, Dec. 2, SUSIM was again
switched off for the eclipse. Otherwise, SUSIM successfully
gathered all of its daily mid-resolution and MgII solar scans
this past week during periods of predicted UARS telemetry.
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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. It has been
discovered that this web site was not updated properly with the latest PEM
data plots. SwRI will investigate the problem.
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 1993365 has been
reprocessed and is archived in the DAAC. HEPSA data reprocessing continues
but has been slowed temporarily while the first 30 days of 1994 data is being
verified.
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.
A poster presentation on the GUVI-PEM comparison from the first conjunction
period is being presented at the American Geophysical Union Fall Meeting.
The poster is titled "Validation of the GUVI Auroral Radiance Measurements
Using the UARS/PEM Instrument" by A Frahm, G Crowley, L J Paxton, C H Jackman,
A B Christensen, D J Strickland, D Morrison, Y Zhang, H Kil, B C Wolven,
J D Winningham, J R Sharber, S K Avery, J D Craven, R R Meier, C I Meng,
P R Straus, C Swenson, and R Waltersheid. An additional presentation on the
overall storm period titled "The Relative Atmospheric Impacts and Energy
Inputs of Precipitating Solar and Magnetospheric Ion and Electron Populations
during the 17-24 April 2002 Events" is being presented by J U Kozyra,
D N Baker, G Crowley, D S Evans, X Fang, R A Frahm, S G Kanekal, M W Liemohn,
G Lu, G M Mason, R A Mewaldt, L J Paxton, E C Roelof, and J D Winningham at the
same meeting.
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 November 2002 (Orbit 61256, GMT Day 327) through
29 November 2002 (Orbit 61360, GMT Day 333).
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 328/1203 61278 POWER ON
ACRIM 329/1715 61296 POWER ON QB A
ACRIM 330/0104 61301 POWER ON QB B ON / QB A OFF
WINDII 330/1303 61303 POWER ON
ACRIM 330/1452 61310 POWER ON QB A ON / QB B OFF
ACRIM 331/0138 61316 POWER ON QB B ON / QB A OFF
ACRIM 331/1303 61324 POWER ON QB A ON / QB B OFF
ACRIM 332/0136 61331 POWER ON QB B ON / QB A OFF
ACRIM 332/1302 61339 POWER ON QB A ON / QB B OFF
PEM 332/1339 61339 AXIS-1 POWER ON
ACRIM 333/0134 61346 POWER ON QB B ON / QB A OFF
ACRIM 333/1301 61354 POWER ON QB A ON / QB B OFF
The beta angle ranged between the angles of 14.3 degrees to 31.4
degrees for this report period. The beta angle is now increasing
towards a maximum angle of 35 degrees on 04 December 2002 (DOY 338).
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 1.29 degrees C. Additional
battery performance data for each battery on 22 November and 29
November 2002 are provided in Appendix D.
The clock error ranged from -8.2 to 0.8 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 = 01
HALOE = 02
WINDII = 01
PEM = 01
ACRIM = 02
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 00
One (1) Anomaly Report remained OPEN at the end of this report period
(see Appendix E).
GROUND SYSTEM OPERATION
Zero (0) 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
A new TAM alignment matrix was uplinked on 21 November 2002 to improve
the attitude performance. As of last week there was a noticeable
difference but with a highly converged filter the attitude error are
taken out very slowly, so the FOT wasn't sure whether the new
alignment had fixed the problem. After monitoring the attitude over
the course of the next week the FOT observed much lower FSS residuals
(on the order of 100 arc seconds) and the attitude seems to be
behaving very well. The FOT is now confident in the attitude solution
for forward flight and will be ready to closely monitor the reverse
flight behavior after the yaw maneuver on 18 December 2002.
The FOT is also in the process of preparing for the upcoming Solar
Eclipse on 04 December 2002. The analysis provided by Flight Dynamics
shows that there will be a significant impact to UARS' power during
the eclipse. The eclipse will take away available solar energy for 3
consecutive orbits. The worst of the three orbits shows a 19 minute
period during UARS power day with up to 66% shadowing. This impact to
UARS power forces the FOT to put all instruments in their off or
standby modes until at least one or two orbits following the eclipse.
The eclipse will begin effecting UARS at 338/0522 and last until
338/0928. The instruments affected by the eclipse are HALOE,
SOLSTICE, SUSIM, HRDI and PEM.
MEETINGS
The FOT attended a NASA Anomaly Review Meeting to discuss the OBC halt
anomaly experienced on 21 October 2002.
FUTURE SIGNIFICANT EVENTS
There will be a Solar Eclipse on 04 December 2002 (DOY 338) beginning
at approximately 0500 until 1000 UTC.
The next UARS Yaw slew is scheduled for 18 December 2002 (DOY 352).
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 November 2002
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
61278 328/1203 02-459 HALOE POWER ON (P-1)
61281 328/1717 02-460 HALOE POWER ON (P-2)
61296 329/1715 02-461 ACRIM POWER ON QB A
61301 330/0104 02-462 ACRIM POWER ON QB B ON / QB A OFF
61309 330/1303 02-463 WINDII POWER ON
61310 330/1452 02-461 ACRIM POWER ON QB A ON / QB B OFF
61313 330/1955 02-464 CDH PMP-B TO MODE F
61316 331/0138 02-462 ACRIM POWER ON QB B ON / QB A OFF
61324 331/1303 02-461 ACRIM POWER ON QB A ON / QB B OFF
61331 332/0136 02-462 ACRIM POWER ON QB B ON / QB A OFF
61339 332/1302 02-461 ACRIM POWER ON QB A ON / QB B OFF
61339 332/1339 02-465 PEM AXIS-1 POWER ON
61346 333/0134 02-462 ACRIM POWER ON QB B ON / QB A OFF
61354 333/1301 02-461 ACRIM POWER ON QB A ON / QB B OFF
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 29 November 2002
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 November 2002
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
-None this report period.
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 29 November 2002
22 November 2002 - GMT Day 326 Beta = 10.8 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 -156.8/-179.2 -3.68/-4.94 +00.0/+00.0 08.3 0.000 0.0
2 +11.2/-22.4 +4.51/+3.23 +28.8/-13.2 26.2 1.040 19.5
3 +28.0/-22.4 +3.23/+2.29 +28.0/-12.8 26.2 1.020 19.1
29 November 2002 - GMT Day 333 Beta = 31.4 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 -156.8/-179.2 -3.05/-3.99 +00.0/+00.0 08.4 0.000 0.0
2 +05.6/-123.2 +6.43/+5.14 +28.8/-15.2 25.0 1.040 22.0
3 +22.4/-67.2 +5.14/+3.87 +28.4/-16.0 24.8 1.030 21.5
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
- None this report period.
APPENDIX E
UARS ANOMALY REPORTS
Week ending 29 November 2002
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
-None this report period.
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
02-057 FOT 60630 285/1008 30382 GENERIC LATE ACQUISITION
02-059 FOT 61191 322/1646 31767 YAW LATE ACQ (HGA TRACK)
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
------ ------ ----- ---- --- -----------------
02-058 FOT 61113 317/1341 N/A NEG ACQ / UFLTR ERROR