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UARS WEEKLY STATUS REPORT - 27 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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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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Nothing received.
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MLS
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The instrument is now off as scheduled.
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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 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.
17 days CLA (7.0) PROD (L1-L3) (473R-209C-13F=251L)
33 days GPI (4.05) PROD (CLAES L3B) (191R-162C=29L)
0 days WIN (5.11) PROD (L1-L3) (1540R-1028C-33F=479L)
2 days HAL (4.82) ENG (L1-L3) (2R-2C=0L)
The CDHF has successfully tested designated days with the HALOE V4.82
Engineering software. PC currently waiting further instructions.
The CDHF has a hold on the WINDII V5.11 mission reprocessing. Testing
against WINDII V5.11A Engineering Software was successful. PC currently
waiting further instructions.
CDHF initiated to draft Cleaning Tape Usage, Maintenance, and
Operations logs for the Rehost System. CDHF personnel are reviewing the
latest Rehost UARS Tape Library Operation draft document. UARS CDHF Rehost
Operational Transition plan was sent to all PI Software Reps.
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FOT
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REPORTING PERIOD
This report covers 14 Aug, 1999 (Orbit 43297, GMT Day 226) through 20 August
1999 (GMT Day 232).
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 229/2327 43356 Off
The beta angle ranged between the angles of 30.9 degrees to 1.2 degrees for
this report period. The beta angle is now increasing toward a maximum angle of
51 degrees on 07 September 1999 (DOY 250).
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 23.8 V end-of-night (EON) load bus voltage. Battery
temperatures are stable with a temperature delta between Battery 2 and Battery
3 of 1.0 to 1.3 degrees C. Additional battery performance data for each
battery on 13 August 1999 and 20 August 1999 are provided in Appendix D.
The clock error ranged from -10.3 to -5.3 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 = 02
The following real-time command sheets were executed for the listed operational
element(s) during this report period (see Appendix A).
% 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
Zero (0) 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 99/231 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 0.0359 percent data loss which equals a 99.9641 percent
data capture for the mission.
There were no data losses this report period.
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
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.
A Forward-to-Reverse Yaw Around maneuver (number 81) was successfully executed
in Orbit 43396 beginning 232/14:45:15 and completing at 232/15:22:25 on 20
August 1999. The SSPP Instruments (ACRIM, SOLSTICE, SUSIM) were enabled as
well as HRDI and PEM in day only operations. Due to the SA position at 269
degrees, the effective night length of the spacecraft after the maneuver was
approximately 52 minutes. Post maneuver analysis of data indicate that during
the Yaw Around, the end-of-night load bus voltage was 24.2 volts and the
average depths of discharge (DODs) on Batteries 2 and 3 were approximately 22.5
and 23.5 percent respectively. The next (reverse-to-forward) YAW is scheduled
for 24 September 1999 (DOY 267).
YEAR 2000 OPERABILITY SUPPORT
None to report this period.
MEETINGS
A meeting was held on Tuesday regarding the upcoming MILA test. As a result of
this meeting it was concluded that UARS did not have any requirements with GN.
This lead to the cancellation of the test.
An MSOCC SERB meeting was held. The FOT received an action item to find out
more about the CNE connection that both the SIM2 and OBCSTF machines have to
the open MODLAN. Apparently, the license on the connection is about to run out
and it must be replaced with a new connection.
FUTURE SIGNIFICANT EVENTS
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.
On Friday the yaw maneuver was executed nominaly.
SIM time has been scheduled for next week for some work with the people from
SCS-21 and NCC.
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 20 August 1999
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ -------
43356 229/2327 99-297 HALOE Power OFF
_______________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 20 August 1999
MNEMONIC STATE DESCRIPTION ORBITS
--------- ----- ------------ ------
HRPTSPBIMON Y-HI PTS Pulse Bus Current Monitor 43318
HRPTSPBIMON R-LO PTS Pulse Bus Current Monitor 43347
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 20 August 1999
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ---- -----------------
None this report period.
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 20 August 1999
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
20 August 1999 - GMT Day 232 Beta = 1.2 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/-4.62 +0.0/+0.0 16.5 0.000 0.0
2 +22.4/-33.6 +5.47/+4.19 +29.6/-13.6 24.3 1.012 21.4
3 +67.2/+0.0 +4.51/+2.92 +29.2/-16.0 24.2 1.014 21.1
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- ---- ----------
no changes V/T 5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 20 August 1999
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
None this report period
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 August 99 14170 Generic Late Acq.
SEVNTFW99/34