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UARS WEEKLY STATUS REPORT - 16 SEP 2005
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SOLSTICE
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Nothing received.
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SUSIM
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Nothing received.
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PEM
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Nothing received.
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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 03 September 2005 (Orbit 76520, GMT Day 246)
through 09 September 2005 (Orbit 76625, GMT Day 252).
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
SOLSTICE 246/0241 76522 POWER ON
HALOE 246/1547 76530 POWER ON
HALOE 247/2345 76550 POWER OFF
HALOE 248/0335 76552 POWER ON
The beta angle ranged between the angles of 59.7 degrees to 34.0
degrees for this report period. The beta angle is now decreasing
towards a minimum angle of 2 degrees on 17 September 2005 (DOY 260).
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 2.56 to 2.23 degrees C. Additional
battery performance data for each battery on 02 September 2005 and 09
September 2005 are provided in Appendix D.
The clock error ranged from 08.4 to -10.4 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 = 05
SOLSTICE = 01
HALOE = 04
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 01
Two (2) Anomaly Reports remained OPEN at the end of this report period
(see Appendix E).
GROUND SYSTEM OPERATION
One (1) operational support problem 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
This week the FOT continues to closely monitor the condition of
battery 2 and battery 3. Battery 2 and 3 have not been sharing load
well since the cell failure on battery 2. Battery 3 carries roughly
2/3 of the power load while battery 2 provides the remaining 1/3. As
the beta angle goes lower, this discontinuity is slowly getting
exaggerated. NASA power branch has been providing daily support in
monitoring the UARS battery condition. The FOT has been authorized to
disable all platform and instrument heaters on the SSPP. This will be
done at the earliest available opportunity.
Analysis of the 6-second calibration burn indicated that one of the
translation thrusters may not have opened fully for the duration of
the burn. This reduced the overall effectiveness of the burn. The
FOT was expecting near 95% duty cycle for this short burn. The
calculated duty cycle for the 6-second calibration burn was
approximately 87%
The FOT has selected a pass during which to do a longer 2nd 4 thruster
calibration burn. This burn will be done on 14 September 2005 (DOY
257) during the 1447 - 1514 support. The burn will be 30 seconds in
length with a start time of 257/14:55:00Z. The primary objective of
this burn is to see attitude and translation thrusters firing, off-
pulsing. A secondary goal of the longer burn is get a better idea on
what the actual duty cycle is using 4-thruster mode.
MEETINGS
There was no De-boost status meeting this week due to the holiday on
Monday. The next De-boost status meeting is scheduled for 12
September 2005.
The FOT attended the weekly Technical Working Group meeting on 08
September 2005. The details for the 30-second calibration burn were
discussed with FDF. The FOT also identified several products that FDF
would need to provide in the event of a no-burn or partial burn.
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 second 4-thruster calibration burn of 30 seconds in length is
scheduled for 14 September 2005 (DOY 257).
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 09 September 2005
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
76521 246/0202 05-309 OBC EPH TOLERANCE OPEN-NEW LOAD
76522 246/0241 05-310 SOLSTICE POWER OFF
76522 246/0241 05-309 OBC EPH TOLERANCE DEFAULT
76530 246/1547 05-311 HALOE POWER ON - PART ONE
76530 246/1621 05-312 HALOE POWER ON - PART TWO
76544 247/1503 05-313 OBC/CLK CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
76550 247/2345 05-314 HALOE POWER OFF
76552 248/0335 05-315 HALOE POWER ON
76590 250/1526 05-316 OBC OBC/PMON
76622 252/1850 05-317 OBC TABLE 58 DUMP
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 09 September 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 09 September 2005
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
76544 247/1503 CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 09 September 2005
02 September 2005 - GMT Day 245 Beta = 59.9 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(%)
--- ------- -------- ---------- ----- ------- ------
1 728.0/ 728.0 -2.74/ -3.99 +00.0/+00.0 04.6 0.00 0.0
2 -700.0/-700.0 +1.34/ +0.40 +16.8/-13.2 25.4 1.08 7.2
3 128.8/-291.2 +5.14/ +3.55 +27.2/-24.0 25.1 1.02 21.2
09 September 2005 - GMT Day 252 Beta = 34.0 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 -2.74/ -3.68 +00.0/+00.0 04.6 0.00 0.0
2 -700.0/-700.0 +3.87/ +2.91 +24.0/-17.6 24.5 1.05 11.5
3 179.2/-291.2 +6.43/ +5.14 +29.6/-23.2 24.5 1.01 24.3
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
-None this report period.
APPENDIX E
UARS ANOMALY REPORTS
Week ending 09 September 2005
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
05-044 FOT 76540 247/0746 30832 Generic Late Acquisition
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
05-043 FOT 76458 241/2148 40662 Late Acquisition
05-032 FOT 76465 242/0757 30832 Generic Late Acquisition
05-045 FOT 76496 244/0901 40682 Late Acquisition/Equip @
WSGT
05-046 OBC 76518 245/2125 N/A Flight Segment Ephem Reject
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
05-044 FOT See List Sept 05 30832 Generic Late Acquisition