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UARS WEEKLY STATUS REPORT - 3 May 2002
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SOLSTICE
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SOLSTICE continues under day only operations due to low power
conditions. We are performing default solar observations during this
time.
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SUSIM
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SUSIM successfully performed its daily mid-resolution and MgII
solar scans during periods of predicted UARS telemetry.
On May 20, Dr. Patrick Crane is leaving the SUSIM group to take a
scientist position with the NRL Remote Sensing Division. Since 1993,
Pat has worked to help to operate and understand the SUSIM instrument
and improve its data. We wish thank him for his contributions and
wish him the best of luck in his new endeavors.
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ACRIM
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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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WINDII
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Nothing received.
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MPG
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The MPG attended the UARS Status Review Meeting on 2 May 2002.
Review on 21 March 2002.
The MPG continues to serve as the point-of-contact for UARS
instrument operations to support re-engineering of the UARS
Mission Operations Concept to develop capabilities for the
Science Traceability Mission.
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 April 2002 (Orbit 57995, GMT Day 110) through 26
April 2002 (Orbit 58099, GMT Day 116).
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 115/0049 58070 AXIS 1,2 POWER OFF
PEM 115/0049 58070 ZEPS / HEPS DAY-ONLY
WINDII 115/1327 58078 POWER ON
The beta angle ranged between the angles of 29.45 degrees to 53.74
degrees for this report period. The beta angle is now increasing
towards a maximum angle of 73 degrees on 03 May 2002 (DOY 123).
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 0.96 to 1.27 degrees C. Additional
battery performance data for each battery on 19 April 2002 and 26
April 2002 are provided in Appendix D.
The clock error ranged from -9.8 to 10.3 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.
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 = 03
PEM AXIS = 03
WINDII = 03
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 0
Three (3) Anomaly Reports remained OPEN at the end of this report
period (see Appendix E).
TRANSPONDER FREQUENCIES:
Transponder A: 01/333 - 2287.496855
Transponder B: 02/043 - 2287.498879
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
The FOT is in the process of implementing some minor changes to the
Eclipse system to help optimize operations. All of the existing
documentation is also in the process of being updated to reflect the
new ground system nomenclature. A few new SOPs have yet to be
written, while the handful that have already been written need to be
finalized and signed off on.
A discussion regarding the UARS power issues will be held at the UARS
Monthly meeting on 02 May 2002. The purpose of this discussion is to
determine a course of action that will improve the power situation for
the summer yaw maneuvers. Options include turning off the instruments
early and delaying their turn on, rolling the spacecraft, driving the
array or changing the V/T limit on the batteries.
MEETINGS
None this report period.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for 23 May 2002 (DOY 143). 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 26 April 2002
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
58017 111/1152 02-141 OBC/CLK CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
58035 112/1657 02-142 OBC/CLK CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
58070 115/0049 02-143 PEM AXIS 1,2 POWER OFF
58070 115/0049 02-144 PEM ZEPS / HEPS DAY-ONLY
58078 115/1327 02-145 WINDII POWER ON
58084 115/2345 02-146 OBC/CLK CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
58094 116/1437 02-147 WINDII RESET TO CLEAR ERROR E06
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 26 April 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 26 April 2002
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
58017 111/1211 CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
58035 112/1659 CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
58084 115/2348 CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 26 April 2002
19 April 2002 - GMT Day 109 Beta = 25.85 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 -3.16/-4.38 +0.0/ +0.0 0.0 0.000 0.0
2 +11.2/ -89.6 +5.14/+4.18 +29.2/-15.2 24.8 1.030 20.7
3 +22.4/-33.6 +4.50/+2.91 +28.4/-15.2 24.8 1.020 20.4
26 April 2002 - GMT Day 116 Beta = 53.74 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 -3.16/-4.38 +0.0/ +0.0 0.0 0.000 0.0
2 +11.2/-100.8 +5.14/+3.87 +24.0/-15.2 24.8 1.040 20.2
3 +22.4/-56.0 +3.87/+2.91 +24.0/-15.2 24.8 1.040 19.9
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- ---- ---------
-no changes V/T 5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 26 April 2002
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
------ ------ ----- ---- --- -----------------
02-025 FOT See List Apr 13 N/A Generic Late Acquisition
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
------ ------ ----- ---- --- -----------------
02-004 SOLSTICE 56883 036/0050 N/A Solstice in Wrong Mode
02-023 FOT 57767 094/2027 24285 Early LOS on OMNI Pass
02-024 FOT 57783 095/2209 24285 SOLSTICE INOPS in Day