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UARS WEEKLY STATUS REPORT - 07 JAN 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.
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SUSIM
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SUSIM continues to gather a minimum 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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The PEM spectrometers continue to be active under PMON control*. While
under PMON control, the PEM spectrometers computed energy deposition from
electrons and protons measured in-situ by the particle spectrometers.
*Beginning of power orbit day (PEM activation): array current >5 amps, array
voltage >53.5 volts, and battery current >2.0 amps.
End of power orbit day (PEM deactivation): time in power orbit day >4 minutes,
array current <9 amps, and battery currents <0.2 amps.
Power orbit day variation: ~39-40 min at yaw to ~50-51 min at maximum beta.
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HALOE
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HALOE was powered off end of day January 3, 2000 as scheduled for the Yaw,
following successful operations. Generally, the use of the tape recorder
to capture the events not covered by the TDRS contacts has worked well.
The HALOE principal investigator and the HALOE FOT appreciate the extra
efforts by the UARS FOT in commanding the tape recorder to maximize the
number of HALOE events each day.
All engineering parameters continue to be within nominal operating range
and the science data products are of excellent quality.
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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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WINDII's first operations for the millennium are scheduled
for January 17-23, 2000.
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MPG
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Routine 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 25 December, 1999 (Orbit 45289, GMT Day 359) through 31
December 1999 (Orbit 45394, GMT Day 365).
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
None this report period.
The beta angle ranged between the angles of 26.8 degrees to 33.2 degrees for
this report period. The beta angle is now decreasing toward a minimum angle of
+1.0 degrees on 06 January 1999 (DOY 006).
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 17 December 1999 and 20 December 1999 are provided in Appendix D.
The clock error ranged from 10.9 to -11.1 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 = 06
% ALERTS = 00
The following real-time command sheets were executed for the listed operational
element(s) during this report period (see Appendix A).
% FOT = 14
UARS Anomaly Reports initiated during this report period are listed in Appendix
E and summarized below.
% FOT = 02
Three (3) Anomaly Reports remained OPEN at the end of this report period (see
Appendix E).
TRANSPONDER FREQUENCIES:
% Transponder A: 99/320 - 2287.496800
% Transponder B: 99/334 - 2287.499196
GROUND SYSTEM OPERATION
Two (2) 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 99/364 show the observatory data loss to be 479 hours, 09
minutes, 32.857 seconds (an increase of 75 hours 05 minutes 52.128 seconds
since the last report period). This is a 0.6609 percent data loss which equals
a 99.3391 percent data capture for the mission.
The increase of 61 hours 55 minutes 32.000 seconds occurred over seven (7)
days:
- 09 hours 58 minutes 28.512 seconds on Day 358 due to a S/C TR problem.
- 11 hours 21 minutes 11.488 seconds on Day 359 due to a S/C TR problem.
- 09 hours 44 minutes 25.728 seconds on Day 360 due to a S/C TR problem.
- 10 hours 41 minutes 50.496 seconds on Day 361 due to a S/C TR problem.
- 11 hours 17 minutes 31.232 seconds on Day 362 due to a S/C TR problem.
- 11 hours 05 minutes 22.496 seconds on Day 363 due to a S/C TR problem.
- 10 hours 57 minutes 02.176 seconds on Day 364 due to a S/C TR problem.
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
The FOT continued scheduling all available TDRS supports in an effort maximize
real-time data collection. In addition, the FOT continued to use the Pass 2
side of NBTR-B to capture sunrise and sunset data, per the request of HALOE
Operations.
Detailed command procedures were put in place for the Y2k transition. Extra
emphasis was placed on the Ephemeris load plan. This load plan would provide
usable ephemeris until Jan 5, 2000.
We are still having problems with the excel spreadsheet files on CDHF and Mike
Anderson is helping us try to diagnose the problem. This will hopefully be
resolved in time for next weeks status report.
The Excel spreadsheet that generates the statistical data for the power
subsystem has stopped running. The FOT is trying to resolve this problem.
YEAR 2000 OPERABILITY SUPPORT
All areas identified to or by the Flight Operations Team for Y2K testing have
been completed. There are no other areas identified at this time that have not
been Y2K certified.
MEETINGS
The FOT did not attend any meetings during this report period.
FUTURE SIGNIFICANT EVENTS
No specific date was agreed upon for UARS Safehold configuration discussions.
Instead, the Supporting Engineers involved will be contacted every two weeks to
determine if either the Flight Operations Team or Supporting Engineers have any
new developments that should be discussed in a group.
UARS has tested and prepared for the Year 2000 event. Special considerations
have been made in preparation for a non nominal 1999 to 2000 transition.
The next UARS Yaw slew is scheduled for January 6, 2000. 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 31 December 1999
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ -------
45300 359/1738 99-432 NBTR NBTR NOOPS
45301 359/1918 99-433 NBTR NBTR NOOPS
45311 360/1008 99-434 OBC Clk Adj 0.00 to 20.6 msec/day
45323 361/0640 99-435 NBTR NBTR NOOPS
45332 361/2104 99-436 OBC Clk Adj 20.6 to 0.00 msec/day
45333 361/2246 99-437 NBTR NBTR NOOPS
45337 362/0502 99-437 NBTR NBTR NOOPS
45347 362/2106 99-438 NBTR NBTR NOOPS
45362 363/2035 99-439 NBTR NBTR NOOPS
45368 364/0651 99-439 NBTR NBTR NOOPS
45377 364/2116 99-440 NBTR NBTR NOOPS
45383 365/0656 99-440 NBTR NBTR NOOPS
45391 365/1855 99-441 NBTR NBTR NOOPS
45393 365/2231 99-442 EPHEM Contingency Ephemeris loads
_______________________________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 31 December 1999
The following Out-Of-Limits occurrences were detected:
MNEMONIC STATE DESCRIPTION ORBITS
--------- ----- ------------ ------
PWICDH Y-LO CDH Current 45298
PWICDH Y-LO CDH Current 45314-5
HRPTSPBIMON Y-HI PTS PB CURR MONITOR 45311-17
HRPTSPBIMON Y-HI HRDI PB CURR MONITOR 45326,30-33
HRPTSPBIMON Y-HI HRDI PB CURR MONITOR continuous
PWICDH Y-LO CDH Current (Engineering) 45381
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 31 December 1999
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ---- -----------------
45311 360/10:10 (26 Dec 99) from 0.00 to 20.6 msec/day
45332 361/21:14 (27 Dec 99) from 20.6 to 0.00 msec/day
_______________________________________________________________________________
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 31 December 1999
20 Dec 1999 - GMT Day 354 Beta = 31.8 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 44.8/-67.2 -3.05/-3.99 +0.0/+0.0 16.2 0.000 0.0
2 +22.4/-44.8 +6.11/+5.15 +30.4/-15.2 24.8 1.030 21.5
3 +44.8/-11.2 +5.15/+3.87 +29.6/-16.0 24.8 1.028 21.3
Not Available
DIFF V (mV) TEMP (C) CURR (amp) EON V AVE C/D AVE
BAT MAX/MIN MAX/MIN MAX/MIN MIN RATIO DOD(%)
---- ---------- ----------- ---------- ------ ------ ------
Not Available
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- ---------- ----------
no changes V/T 5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 31 December 1999
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-097 FOT 45293 359/0537 N/A AP Crashed
99-098 FOT 45375 364/1709Z 21790 Late Acq/3:43 Lost NRec
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-097 FOT 45293 359/0537 N/A AP Crashed
99-098 FOT 45375 364/1709Z 21790 Late Acq/3:43 Lost NRec
ANOMALY INVESTIGATION REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
No new reports generated
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
99-071 FOT 44398 299/1212 21512 TPF Not Receiving 512 PB
99-089 FOT 45095 346/0123 14170 Generic Late Acquisition
SEVNTFW99/53