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UARS WEEKLY STATUS REPORT - 14 July 2000
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SOLSTICE
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We continue to gather enough data to meet all the SOLSTICE science
objectives during this period of reduced tape recorder operations.
SOLSTICE operates normally, collecting solar data on all available
orbital tracking periods and stellar calibration observations whenever
possible. Level 2 processing is halted due to bugs in the OA_SSPP_ATT
service. CDHF and CSC personnel are working on the problem.
Solar pointing performance has been unaffected by the star tracker #2
failure. Stellar pointing performance is suspected to be worse and we
are evaluating the impact.
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SUSIM
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SUSIM continues to gather a normal set of daily solar scans scheduled
for periods of predicted telemetry.
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ACRIM
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Nothing received.
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PEM
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At the present time, the PEM is not active...may UARS get better soon.
Recent data configuration changes have affected PEM software causing multiple
failures. These failures are being reviewed by the PEM team. In order to
correct for new telemetry requirements, PEM will need to update processing
code with a patch delivery. The delivery patch will not include changes which
would allow the PEM software to execute on a DEC Alpha machine.
Updated HEPS calibration parameters have been finalized and are ready for
delivery. Updated MEPS quality calibration files have been finalized and are
ready for delivery. Level 3 software errors, discovered by Dr. Dean Pesnell,
have been fixed; his suggestions have been incorporated with in the PEM
production code. Both updated HEPS and MEPS calibration data, along with the
Level 3 code changes, will influence the in-situ energy deposition predictions,
so new versions of PEM energy deposition Level 3 files will be generated.
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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 has been assisting with analysis of the potential impact
resulting from the failure of the UARS Fixed Head Star Tracker 2.
It now appears that UARS spacecraft attitude control and
knowledge can be maintained by using the Fine Sun Sensor along
with periodic use of Fixed Head Star Tracker 1.
Processing of instrument Daily Activity Plans continues with no
problems. We are continuing to coordinate with the Flight
Operations Team and to assist the Project Scientist in the
scheduling of instrument operations.
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CDHF
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Continue to notify all PI Software Representatives when Data Gaps
occur in the LEVEL0 data due to the UARS Spacecraft Anomaly.
Data created in the month of May, 2000 has been previewed for HALOE, NMC,
and UKMO in preparation for the DAAC.
UARS CDHF REHOST:
- The CDHF is waiting validation results from the HRDI group on successful
production testing done on the Rehost System.
- Successful processing on Rehost System:
Attitude Extraction, Observatory Log, Sensor Extraction, HALOE, HRDI,
MLS, SUSIM, Solstice, and WINDII.
- The preview and loading of April, 2000 NMC and UKMO data into the
DAAC Transfer Tables has been successful on the Rehost System.
The DAAC has been notified to try the transfers.
- The UKMO data was migrated from the Current System and the NMC
data was ingested electronically on the Rehost System.
- NMC Data created in the month of May, 2000 has been previewed on the
Rehost System for (Height, Moisture, Temp, and Winds).
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FOT
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REPORTING PERIOD
This report covers 1 July 2000 (Orbit 48122, GMT Day 183) through 7 July 2000
(Orbit 48226 , GMT Day 189).
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
ACRIM 185/0030 48152 Power OFF
SUSIM 185/0030 48152 Power OFF
PEM 185/0030 48152 Power OFF
HRDI 185/0030 48152 Low Power
PEM 185/1130 48159 PEM PMON Group DISA
ACRIM 188/0020 48197 Power ON
SUSIM 189/1403 48220 Power ON
A Reverse-to-Forward Yaw Around maneuver (number 90) was successfully executed
in Orbit 48175 beginning 186/13:51:15 and completing at 186/14:28:25 on 04 July
2000. The SOLSTICE instrument was enabled and all other intruments were in
their off or standby mode (including the day only instruments). Due to the SA
position at 269 degrees, the effective night length of the spacecraft after the
maneuver was approximately 53.79 minutes. Post maneuver analysis of data
indicate that during the Yaw Around, the end-of-night load bus voltage was
24.12 volts and the average depths of discharge (DODs) on Batteries 2 and 3
were approximately 21.55 and 21.20 percent respectively. The next (forward-to-
reverse) YAW is scheduled for 14 August 2000 (DOY 227).
The beta angle ranged between the angles of 9.5 degrees to 10.6 degrees for
this report period. The beta angle is now increasing toward a maximum angle of
+76.0 degrees on 25 July 2000 (DOY 207).
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 23 June 2000 is provided in Appendix D.
The clock error ranged from -6.2 to 5.7 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.
The FHST-2 temperature out of limits condition appears to be a "failure" of
FHST-2. Further details of this "failure" and any information on the work
around will be reported in the next weekly report.
% OUT-OF-LIMITS = 01
% ALERTS = 00
The following real-time command sheets were executed for the listed operational
element(s) during this report period (see Appendix A).
% FOT = 10
% ACRIM = 02
% SUSIM = 02
% PEM = 02
% HRDI = 01
UARS Anomaly Reports initiated during this report period are listed in Appendix
E and summarized below.
% FOT = 01
Three (3) Anomaly Reports remained OPEN at the end of this report period (see
Appendix E).
TRANSPONDER FREQUENCIES:
- Transponder A: 00/145 - 2287.497008
- Transponder B: 00/152 - 2287.498920
GROUND SYSTEM OPERATION
One (1) 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 00/181 show the observatory data loss to be 296 hours, 32
minutes, 34.041 seconds (an increase of 12 minutes 26.328 seconds since the
last report period). This is a 0.40 percent data loss which equals a 99.60
percent data capture for the mission.
The increase of 12 minutes 26.328 seconds occurred over four (4) days:
- 0 minutes 57.264 seconds on Day 175 due data hits,
- 3 minutes 44.336 seconds on Day 177 due to a software problem at WSC,
- 7 minutes 28.416 seconds on Day 179 due to an unknown reason,
- 0 minutes 16.312 seconds on Day 180 due to data hits.
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
The FOT continues to test the new TMONs. Once the TMONs have been thoroughly
tested, they will be presented for review and approval before uplink.
The FOT has begun writing the online procedure for safehold should it happen
before the new TMONs are in place or during and OBC halt. This procedure will
be tested on the simulator and put online for immediate execution should an
anomalous condition take place.
MEETINGS
The FOT attended the UARS monthly status meeting on 05 July 2000.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for August 14, 2000 (DOY 227). This
maneuver will be a Forward to Reverse Flight maneuver (Northern Hemisphere
viewing).
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 07 July 2000
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ -------
48125 183/0608 00-305 NBTR NOOPS D-183
48133 183/1729 00-305 NBTR NOOPS D-183
48133 183/1806 00-306 NBTR NOOPS D-184
48140 184/0547 00-306 NBTR NOOPS D-184
48148 184/1732 00-306 NBTR NOOPS D-184
48152 185/0030 00-307 ACRIM Power OFF
48152 185/0030 00-308 SUSIM Power OFF
48152 185/0030 00-309 PEM Power OFF
48152 185/0030 00-310 HRDI Low Power
48159 185/1130 00-311 PEM PEM PMON Group DISA
48175 186/1315 00-312 OBC YAW MANEUVER
48197 188/0020 00-313 ACRIM Power ON
48220 189/1403 00-314 SUSIM Power ON
48223 189/1735 00-315 FHST TESTING
48224 189/1922 00-316 NBTR DOY 190 NOOPS
48225 189/2104 00-317 FHST TESTING
48225 189/2104 00-318 TAM TAM TO MONITOR MODE
_______________________________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 07 July 2000
The following Out-Of-Limits occurrences were detected:
MNEMONIC STATE DESCRIPTION ORBITS
--------- ----- ------------ ------
MAST2TEMP Y-LO FHST 2 TEMPERATURE 48210
The following ALERT occurrences were detected:
MNEMONIC DESCRIPTION ORBITS
--------- ------------ ------
-None this report period
_______________________________________________________________________________
APPENDIX C
CLOCK & SOLAR ARRAY RATE CORRECTIONS
Week ending 07 July 2000
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ---- -----------------
-None this report period
_______________________________________________________________________________
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 07 July 2000
30 June 2000 - GMT Day 182 Beta = 9.5 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 +44.8/+22.4 -3.68/-4.31 +0.0/+0.0 15.7 0.000 0.0
2 +11.2/-11.2 +4.83/+4.51 +18.4/-13.6 26.4
3 +11.2/-11.2 +3.87/+3.23 +17.6/-13.2 26.2
07 July 2000 - GMT Day 189 Beta = 10.6 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 +44.8/+22.4 -3.68/-4.94 +0.0/+0.0 15.5 0.000 0.0
2 +11.2/-11.2 +4.51/+3.87 +28.8/-13.6 26.1
3 +28.0/-11.2 +3.55/+2.60 +28.0/-13.2 25.9
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- ---------- ----------
no changes V/T 5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 07 July 2000
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
00-030 FOT 48211 188/2242 22631 Intermittent drop outs
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
------ ------ ----- ---- --- -----------------
99-064 FOT 44135 10/8-9/99 N/A HRDI Cal Lamp Errors
00-026 FOT see list June 00 14170 Generic Late Acq.
00-030 FOT 48211 188/2242 22631 Intermittent drop outs
SEVNTFW00/27