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UARS WEEKLY STATUS REPORT - 02 SEP 2005
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SOLSTICE
***********
Nothing received.
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SUSIM
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Nothing received.
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PEM
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HEPSA data files are version 2. Currently, HEPSA data between 1991274
and 2004273 has been reprocessed and archived at the GSFC DAAC. HEPSA data
between 2004274 and 2005099 has been processed and is waiting for archival
at the DAAC.
MEPS data files are version 1. Processed MEPS data files at the DAAC
archive are between 1991274 and 2004259. MEPS data between 2004260 and
2005099 has been processed and is waiting for DAAC archival.
HEPSB data files are version 1. HEPSB data files between 1991274 and
1991366 have been processed and are waiting for DAAC archival.
Processing of all PEM DAAC data files has been suspended until the
DAAC catches up with archiving all processed data files. PEM data from
1991272 through 2005169 are available from SwRI. Users of SDDAS have this
data currently available. Please update your meta data to reflect the
current PEM data holdings.
Tests of the AXIS1 data file formats have been successful. The AXIS1
format design has been coded. A test file has been generated. A check
program with processing scripts have also been generated. Example binary
read program is now under development and will be tested on the generated
example binary data file.
PEM continues to receive NMC data files from NOAA. No problems have
been encountered since updates have occurred.
The PEM data from the GUVI conjunction periods may be found at
http://wwwpem.space.swri.edu/guvi-pem.html. The additional electron data for
the October and November storms of 2003 has been moved and is now located at
http://climatology.space.swri.edu/uars_fromRudy.html. For those users of
SDDAS, update your UARS Meta data and these data times will appear
with full functionality. Proton data from these storms are now located at
http://climatology.space.swri.edu/UARS_images_from_Rudy_(Apr._2004).html
Requests have been received for storm spectral data. Overview plots were
produced and these plots may be found on the web at
http://climatology.space.swri.edu/UARS_images_postedJune2004.html
for the storms of October 29 of 1991, November 8-9 of 1991, April 6-7 of 2000,
March 31 - April 1 of 2001, April 11-12 of 2001, November 6-7 of 2001, and
November 11-12 of 2001.
PEM has received a request for data from the super storm of November
2004. The Dst value showed sudden commencement early on November 7, 2004
reaching a Dst value of about -380 gamma early on November 8, 2004.
PEM was not active at that time and became active late on November 8, 2004
in day only mode. A second peak of about -280 gamma was observed on November
11, 2004. PEM became active in day-light only mode late on November 8. PEM
survey spectrograms for November 8-18 of 2004 may be found at:
http://climatology.space.swri.edu/UARS_images_fromRudy.html
*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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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 20 August 2005 (Orbit 76309, GMT Day 232) through
26 August 2005 (Orbit 76414, GMT Day 238).
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
PEM 234/0127 76340 OFF TO DAY ONLY
SOLSTICE 234/0127 76340 OFF TO DAY ONLY
HALOE 234/0127 76340 POWER OFF
PEM 235/1505 76364 DAY ONLY TO OFF
SOLSTICE 235/1505 76364 DAY ONLY TO OFF
HALOE 236/1835 76381 POWER ON
HALOE 237/2339 76399 POWER OFF
The beta angle ranged between the angles of 38.7 degrees to 62.1
degrees for this report period. The beta angle is now increasing
towards a maximum angle of 66 degrees on 29 August 2005 (DOY 242).
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 3.87 to 1.27 degrees C. Additional
battery performance data for each battery on 19 August 2005 and 26
August 2005 are provided in Appendix D.
The clock error ranged from 10.0 to -12.1 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 = 13
PEM = 02
SOLSTICE = 02
HALOE = 04
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 02
Two (2) Anomaly Reports remained OPEN at the end of this report period
(see Appendix E).
GROUND SYSTEM OPERATION
Two (2) 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 21 August 2005 during the break between 233/2247-2307 and 233/2347-
2359 UARS lost a cell on battery 2. The online crew noticed a red
alarm indicating that the differential voltage on battery 2 was at
-700mV, the previous orbit it was at -184.8mV. It was also noticed
that the C/D ratio on battery 2 had gone from a previous orbit value
of 1.04 to 1.16, at the same time the ratio on battery 3 had gone from
1.02 to 0.99. Also, battery 2 temperatures had increased dramatically
from 8.50 C to 16.56 C. All signs indicated a shorted cell on battery
2.
Immediate action was taken by the FOT to keep battery 2 from being
overcharged, and try to prevent any other cells from possibly failing.
In order to achieve this, the HALOE instrument was turned off, PEM was
commanded to day only, SOLSTICE was commanded to day-only, and the VT
level was changed, with approval from NASA power branch, from L5 to L4
at 234/0106Z, during spacecraft day. VT Levels were dropped again
from L4 to L3 at 234/0319Z. This was done because the change to L4
did not keep battery 2 from reaching a very high C/D ratio of 1.36.
It was decided that in order to reduce the high C/D ratio on battery
and fully charge battery 3, that battery 2 would have to be taken off
charge relay once it reaches Full Charge plus 1 minute. Battery 3
would remain on the charge relay and take as much as it needs to
achieve power balance. This means that for the first several minutes
of spacecraft night battery 3 would be providing all of the power to
the bus until battery 2 is brought back on relay. Battery 2 is placed
back on the relay after about 4 minutes into spacecraft night.
Two TMON's were created to take the proper action as needed. TMON 45
and TMON 46 were confiscated for the task since they were disabled and
no longer in use. TMON 45 is used to take battery 2 off charge relay
once it reaches full charge + 1 minute. TMON 46 puts battery 2 back
on relay 4 minutes after spacecraft power night is seen. The new
TMON's were tested against the UARS UTTS simulator and verified to
work as expected. Then with the Mission Directors' approval they were
loaded to the spacecraft and enabled on the 234/0642Z contact.
The charge level was left at VT-3 to ensure that battery 2 was not
being over charged. While in VT-3 battery 2 temperatures slowly
decreased from its high of 16.56 C. The VT charge level was increased
to VT-4 on the 234/1409Z contact because battery 3 was not returning
to 100% state of charge under the TMON controlled charging scheme.
Minor tweaks to the timings in TMON 45 and 46 have been made as we get
a better understanding of how the batteries are operating in this new
charging mode. One last change to the charging level, to VT-5, was
made on 235/1725Z contact.
MEETINGS
The loss of a cell on battery 2 was a trigger point to begin UARS End
Of Mission activities. Since a kickoff meeting for de-boost
activities was scheduled for 22-August 2005, End of Mission activities
and planning was added to the agenda. An idea to try to implement a 4-
thruster translation mode was discussed and given approval to go ahead
and attempt to implement. FDF and the FOT agreed that this mode of
operations, if successful, could significantly reduce the number of
burns needed to lower UARS.
The FOT also attended a follow on Technical Working Group meeting on
25 August 2005. During this meeting a high level schedule for when
calibration burns and orbit lowering burns are to be done was agreed
to. FDF presented that UARS would need no more than 6 burns of 15-20
minutes to empty the remaining fuel onboard and lower perigee to ~
315KM. In the resulting elliptical orbit UARS would re-enter
uncontrolled on its own between 3 to 3 « years.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for 17 September 2005 (DOY 260).
This maneuver will be a Forward to Reverse Flight maneuver (Northern
Hemisphere viewing).
A patch to the OBC to allow for 4-thruster mode is planned for 30
August 2005. A 4-thruster calibration burn of 2-3 seconds in length
is scheduled for 01 September 2005.
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 26 August 2005
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
76310 232/0133 05-270 OBC/CLK CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
76340 234/0050 05-271 MPS VT LVL 4
76340 234/0127 05-273 PEM & SOLS PEM & SOLSTICE TO DAY ONLY
76340 234/0127 05-272 HALOE HALOE OFF
76342 234/0319 05-275 OBC DUMP TABLES 29 & 30
76342 234/0319 05-274 MPS VT LVL 3
76344 234/0642 05-276 OBC/TMON LOAD TABLES 45 & 46
76348 234/1409 05-276 OBC/MPS ENA TMON 45,46 RPT, VT LVL 4
76349 234/1545 05-277 OBC/TMON DISA TMON 45,46 RPT
76364 235/1505 05-278 PEM/SOLS PEM/SOLS DAY ONLY TO OFF
76365 235/1721 05-279 MPS VT LEVEL 4 TO 5
76380 236/1650 05-280 OBC RELOAD TMON 45,46
76381 236/1835 05-281 HALOE HALOE ON (PT 1)
76383 236/2055 05-282 OBC/CLK CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
76384 236/2237 05-283 HALOE POWER ON
76398 237/2200 05-284 OBC/MAGMOD UPDATE FSW MAGMOD OFFSET
76399 237/2339 05-285 HALOE POWER OFF
76410 238/1645 05-286 OBC/MPS TMON 45 UPDATE
76411 238/1717 05-287 OBC/CLK CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 26 August 2005
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 26 August 2005
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
76310 232/0140 CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
76383 236/2059 CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
76411 238/1730 CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 26 August 2005
19 August 2005 - GMT Day 231 Beta = 38.4 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(%)
--- ------- -------- ---------- ----- ------- ------
1 728.0/ 728.0 -2.42/ -3.68 +00.0/+00.0 04.6 0.00 0.0
2 -50.4/-347.2 +14.55/ +9.06 +31.6/-19.6 25.1 1.07 22.2
3 33.6/-700.0 +4.82/+ 3.23 +19.2/-12.0 25.0 1.04 13.0
26 August 2005 - GMT Day 238 Beta = 62.1 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(%)
--- ------- -------- ---------- ----- ------- ------
1 728.0/ 728.0 -3.68/ -4.63 +00.0/+00.0 04.6 0.00 0.0
2 -700.0/-700.0 +7.74/ +3.87 +22.0/-17.6 25.8 1.09 11.8
3 196.0/-700.0 +3.87/ +2.60 +19.2/-20.8 25.6 1.03 16.3
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
76340 234/0050 LV5 -> LV4
76342 234/0319 LV4 -> LV3
76348 234/1409 LV3 -> LV4
76365 235/1721 LV4 -> LV5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 26 August 2005
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
05-042 MPS 76339 233/2347 N/A BATTERY 2 DIFFV -700mV
05-043 FOT 76404 238/0730 30832 Generic Late Acquisition
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
05-039 FOT 76162 222/0506 40451 WS Chain Failover
05-040 FOT 76176 223/0244 40465 TLM HITS - WEATHER AT
GUAM
05-041 FOT 76183 223/1443 40470 TLM DROPOUT - WEATHER AT
GUAM
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
------ ------ ----- ---- --- -----------------
05-042 MPS 76339 233/2347 N/A BATTERY 2 DIFFV -700mV
05-043 FOT See List August 05 30832 Generic Late Acquisition