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UARS WEEKLY STATUS REPORT - 20 AUG 1999
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SOLSTICE
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SOLSTICE continues to operate normally, collecting solar data on all
available orbital tracking periods and stellar calibration observations,
whenever possible.
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SUSIM
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After being turned off for the Aug. 11 eclipse, SUSIM gathered its
normal solar, offset, and occultation data this past week without
apparent problems.
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ACRIM
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Nothing received.
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PEM
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The PEM spectrometers continue to be active under PMON control. While
under PMON control, the PEM instrument computed energy deposition from its
particle spectrometers.
The FOT and the PEM team are completing reducing activation time
regarding the HEPS Energy Processor trouble.
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HALOE
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HALOE was powered off on August 18, 1999 in preparation for the Yaw
maneuver today. HALOE had been operating successfully with all engineering
parameters within nominal operating range. HALOE is schedule to turn on
mid-day August 23, 1999.
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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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Routine processing of instrument Daily Activity Plans continues
with no problems. The MPG continues to assist the Project
Scientist with the scheduling of instrument operations.
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CDHF
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The CDHF notified Software Representatives using the Auxiliary (SOL) data that
it had been delayed this past week due to a computer failure which
occurred at the Solar Terrestrial Dispatch.
The CDHF processed current day data through level 3 for all active
instruments. Additionally, CDHF personnel reprocessed: (R)= Requested
(C) = Complete, (F)= Failed (L) = Days remaining to reprocess.
19 days CLA (7.0) PROD (L1-L3) (473R-192C-12F=269L)
39 days GPI (4.05) PROD (CLAES L3B) (165R-129C=36L)
0 days WIN (5.11) PROD (L1-L3) (1540R-1028C-33F=479L)
2 days WIN (5.11A) ENG (L1-L3) (7R-7C=0L)
0 days HAL (4.82) ENG (L1-L3) (2R-2F=2L)
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FOT
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REPORTING PERIOD
This report covers 7 Aug, 1999 (Orbit 43192, GMT Day 219) through 13 August,
1999 (GMT Day 225).
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
HRDI 223/0400 43254 Off
SUSIM 223/0732 43257 Off
ACRIM 223/0732 43257 Off
SOLSTICE 223/0732 43257 Off
ACRIM 223/1421 43261 On
SOLSTICE 223/1602 43262 On
HALOE 223/1823 43263 On
SUSIM 223/1929 43264 On
WINDII 224/0222 43269 On
HRDI 224/0222 43269 On
HRDI 224/0414 43269 Off
HRDI 224/1140 43274 On
WINDII 225/1830 43293 Off
The beta angle ranged between the angles of 60.2 degrees to 30.9 degrees for
this report period. The beta angle is now decreasing toward a minimum angle of
2.0 degrees for the yaw maneuver on 20 August 1999 (DOY 232).
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 23.7 V end-of-night (EON) load bus voltage. Battery
temperatures are stable with a temperature delta between Battery 2 and Battery
3 of 0.7 to 1.0 degrees C. Additional battery performance data for each
battery on 06 August 1999 and 13 August 1999 are provided in Appendix D.
The clock error ranged from 10.9 to -10.5 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.
% ALERTS = 00
% OUT-OF-LIMITS = 00
The following real-time command sheets were executed for the listed operational
element(s) during this report period (see Appendix A).
% FOT = 04
% HRDI = 04
% SUSIM = 04
% WINDII = 02
% ACRIM = 02
% SOLSTICE = 02
% HALOE = 01
UARS Anomaly Reports initiated during this report period are listed in Appendix
E and summarized below.
% FOT = 00
Zero (0) Anomaly Report remained OPEN at the end of this report period (see
Appendix E).
TRANSPONDER FREQUENCIES:
% Transponder A: 99/208: 2287.496910
% Transponder B: 99/209: 2287.498901
GROUND SYSTEM OPERATION
Five (5) operational support problems occurred this period. Anomaly Reports
are included in Appendix E.
The data loss calculations supplied by Data Capture Facility (DCF) from mission
start through UTC Day 99/224 show the observatory data loss to be 24 hours, 54
minutes, 50.292 seconds (an increase of 6.272 seconds since the last report
period). This is a 0.0360 percent data loss which equals a 99.9640 percent
data capture for the mission.
The increase of 6.272 seconds occurred over four (4) days:
7 0.224 seconds on DOY 218 due to data hit.
7 4.064 seconds on DOY 223 due to IP line hit.
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
FOT personnel are supporting the IMOC (SCS-21) development effort. The current
work is a continuation of the SCS-21 UARS implementation effort done last year
which culminated in a level 1 demonstration.
The FOT continues to investigate the feasibility of a new PMON action to change
battery V/T curves based on loading to mitigate battery risks in sun pointing
safehold.
YEAR 2000 OPERABILITY SUPPORT
Y2K End to End testing is scheduled for the following week.
MEETINGS
No meetings were held or attended by the FOT.
FUTURE SIGNIFICANT EVENTS
August 20, 1999 (DOY 232): The next UARS Yaw Around Maneuver (forward-to
reverse) is scheduled.
September, 1999: A meeting is planned for the beginning of September to
discuss the UARS Safehold configuration and concerns for the MPS and its
batteries. This meeting will be a closed meeting with only the FOT and
specialized engineering support attending.
PERSONNEL CHANGES
None.
Attachments: Appendix A, Real-time Commands 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 13 August 1999
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ -------
43209 220/0258 99-277 OBC Clk Adj fr 0.00 to 20.6 msec/day
43239 222/0357 99-278 OBC Clk Adj fr 20.6 to 0.00 msec/day
43254 223/0400 99-279 HRDI Power OFF (ECLIPSE)
43257 223/0732 99-280 SUSIM Power OFF (ECLIPSE)
43257 223/0732 99-282 ACRIM Power OFF (ECLIPSE)
43257 223/0732 99-283 SOLSTICE Power OFF (ECLIPSE)
43261 223/1421 99-284 ACRIM Power ON (ECLIPSE)
43262 223/1602 99-285 SOLSTICE Power ON (ECLIPSE)
43263 223/1823 99-286 HALOE Power ON (ECLIPSE)
43264 223/1929 99-287 SUSIM Power ON (ECLIPSE)
43269 224/0222 99-288 WINDII Power ON
43269 224/0222 99-289 HRDI Power ON
43269 224/0414 99-290 HRDI Power OFF
43274 224/1140 99-291 HRDI Power ON
43277 224/1615 99-292 OBC Clk Adj fr 0.00 to 20.6 msec/day
43279 224/2009 99-293 SUSIM MPL Replacement
43280 224/2131 99-294 SUSIM LOOP Fix
43293 225/1830 99-295 WINDII Power OFF
43296 225/2318 99-296 OBC Clk Adj fr 20.6 to 0.00 msec/day
_______________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 13 August 1999
MNEMONIC STATE DESCRIPTION ORBITS
--------- ----- ------------ ------
No Out-of-Limits conditions to report this period.
The following ALERT occurrences were detected:
MNEMONIC DESCRIPTION ORBITS
--------- ------------ ------
No Alerts to report this report period.
_______________________________________________________________
APPENDIX C
CLOCK & SOLAR ARRAY RATE CORRECTIONS
Week ending 13 August 1999
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----------------------- --------------------------
43209 220/03:02 (07 Aug 99) from 00.0 to 20.6 msec/day
43239 222/04:00 (10 Aug 99) from 20.6 to 00.0 msec/day
43277 224/16:24 (12 Aug 99) from 00.0 to 20.6 msec/day
43296 225/23:24 (13 Aug 99) from 20.6 to 00.0 msec/day
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 13 August 1999
6 August 1999 - GMT Day 218 Beta = 60.2 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 -112.0/-134.4 -3.05/-4.31 +0.0/+0.0 16.5 0.000 0.0
2 +22.4/-11.2 +4.51/+2.60 +23.2/-15.2 26.4 1.025 17.2
3 +33.6/-16.8 +3.23/+1.66 +23.2/-14.4 26.2 1.020 16.7
13 August 1999 - GMT Day 225 Beta = 30.9 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 -112.0/-134.4 -2.73/-3.68 +0.0/+0.0 16.5 0.000 0.0
2 +39.2/-5.6 +7.41/+5.15 +29.6/-16.0 23.8 1.021 23.4
3 +56.0/+0.0 +6.44/+4.51 +29.6/-16.4 23.8 1.026 23.0
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- ---------- ----------
no changes V/T 5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 13 August 1999
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-039 FOT 43238 222/0217 14170 Generic Late Acq.
99-039 FOT 43263 223/1823 14170 Generic Late Acq.
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
None this report period
ANOMALY INVESTIGATION REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
None this report period
OPEN ANOMALY REPORTS
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-033 FOT see list July 99 14170 Generic Late Acq.
SEVNTFW99/33