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UARS WEEKLY STATUS REPORT - 29 AUGUST 2003
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SOLSTICE
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For three days this week, SOLSTICE was powered and taking solar data
only during daylight in support of the yaw maneuver. Otherwise, solar
data were collected on all available orbital tracking periods.
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SUSIM
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SUSIM was turned off on Tuesday, Aug. 26. Otherwise, the experiment
successfully gathered all of its daily mid resolution, weekly
offset, and O2 occultation scans during periods of UARS telemetry or
periods of onboard tape recording.
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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 continues to serve as the point-of-contact for UARS
instrument operations in support of the Science Traceability
Mission of UARS. On 27 August the MPG attended a meeting held
to discuss problems, concerns, and tasks connected with
modifying UARS spacecraft and ground systems so that UARS can
relay data and telemtry through 3 TDRS spacecraft each orbit.
Currently, UARS is limited by software constraints to the use
of 2 TDRS spacecraft.
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 16 August 2003 (Orbit 65255, GMT Day 228) through
22 August 2003 (Orbit 65359, GMT Day 234).
SPACECRAFT OPERATION
The observatory is now in Reverse Flight (Northern Hemisphere viewing)
and is performing nominally under two-battery operations. The
instrument operational changes were:
INSTRUMENT OPERATIONAL CHANGES
Instrument Time Orbit Comment
WINDII 230/2259 65299 POWER OFF
PEM 234/2141 65358 POWER OFF AXIS 1 / ZEPS-NEPS
The beta angle ranged between the angles of 37.0 degrees to 20.6
degrees for this report period. The beta angle is now decreasing
towards a minimum angle of 0 degrees on 27 August 2003 (DOY 239).
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 1.28 to 1.29 degrees C. Additional
battery performance data for each battery on 15 August and 22 August
2003 are provided in Appendix D.
The clock error ranged from -12.1 to 10.1 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 = 05
WINDII = 01
PEM = 01
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
After several discussions with the Raytheon development team, the FOT
was able to reproduce the error found in the Eclipse scripting
executable (CECIL.exe). The error manifests itself in a slightly
different manner on the UARS network than the ERBS network, so the FOT
needed to determine that the same error was being seen on both
systems. The patch has been tested on the prototype and will be
released for operations early next week.
On 15 August, the VT-6 charge level was utilized to support the WINDII
turn on. The batteries were left in this charge rate until the
230/1421 event on 18 August 2003. Telemetry showed no signs that VT-6
was overcharging the batteries, but the FOT did not want to utilize
this aggressive charge rate for longer than three days. After going
back to VT-5 the end-of-night load bus voltage dropped all the way
down to 23.8 V and WINDII was powered off on the 230/2259 event, to
prevent an unsafe power condition. The future operations of WINDII
will have to be reviewed by the FOT, UARS project scientist and the
NASA power branch in order to come up with a viable solution.
Fortunately, this turn on has at least provided some good data with
which to make that decision.
MEETINGS
The FOT attended the biweekly UARS DRB meeting to review open Eclipse
DRs.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for 27 August 2003 (DOY 239).
This maneuver will be a Reverse to Forward Flight maneuver (Southern
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 22 August 2003
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
65282 229/1928 03-213 OBC/CLK CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
65294 230/1503 03-214 MPS VT6 TO VT5 & RESET SOC
65298 230/2126 03-215 OBC/CLK CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
65299 230/2259 03-216 WINDII POWER OFF
65303 231/0622 03-217 OBC/CLK CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
65320 232/0908 03-218 OBC/CLK CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
65358 234/2141 03-219 PEM POWER OFF AXIS 1 / ZEPS-NEPS
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 22 August 2003
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 22 August 2003
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
65282 229/1928 CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
65298 230/2126 CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
65303 231/0622 CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
65320 232/0910 CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 22 August 2003
15 August 2003 - GMT Day 227 Beta = 38.8 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 -700.0/-700.0 -2.42/-4.31 +00.0/-50.0 07.2 0.000 0.0
2 +11.2/-72.8 +7.09/+4.19 +26.8/-50.0 25.4 1.040 23.0
3 +22.4/-67.2 +5.79/+3.23 +26.4/-50.0 25.4 1.040 22.5
22 August 2003 - GMT Day 234 Beta = 20.6 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 -700.0/-700.0 -3.05/-3.99 +00.0/+00.0 07.2 0.000 0.0
2 +33.6/-16.8 +6.44/+5.15 +28.8/-14.4 23.8 1.030 21.2
3 +22.4/-50.4 +5.15/+3.87 +28.0/-14.4 23.8 1.020 21.0
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
65294 230/1503 LV6 -> LV5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 22 August 2003
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
03-037 FOT 65336 233/0949 30832 Generic Late Acquisition
03-044 FOT 65347 234/0433 33557 33 sec Data Dropout
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
03-042 TDW 65186 223/1109 33437 TDW Could not support
03-043 FOT 65238 226/2119 N/A Excessive Data Dropouts
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
------ ------ ----- ---- --- -----------------
03-037 FOT See List August 03 30832 Generic Late Acquisition
03-044 FOT 65347 234/0433 33557 33 sec Data Dropout