********************************************************************
UARS WEEKLY STATUS REPORT - 22 DEC 2000
********************************************************************
***********
SOLSTICE
***********
Nothing received.
***********
SUSIM
***********
Nothing received.
***********
ACRIM
***********
Nothing received.
***********
PEM
***********
The PEM zenith spectrometers are activate in daylight mode.
At the present time, PEM energy deposition from its spectrometers is not
being generated. 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 may include changes
which would allow the PEM software to execute on a DEC Alpha machine. GSFC is
helping PEM with some DEC Alpha particulars which have caused PEM level 3
code to fail on DEC Alpha machines (software below level 3 executes on the
DEC Alpha).
The PEM team is working on replacing the PEM:: machine with a DEC Alpha
machine to be called PEM2K::. Initial tests of telemetry transfers through
PEM2K:: have been successful; however, unexplained missing transfers have
occurred to PEM2K::. PEM Telemetry is runing in duplicate streams through
PEM:: and PEM2K::. We find that there are occasional files which transfer
from the CDHF to PEM::, but are missing from PEM2K::.
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.
*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.
***********
HALOE
***********
Nothing received.
***********
MLS
***********
Nothing received.
***********
HRDI
***********
Nothing recieved.
***********
WINDII
***********
Nothing received.
***********
MPG
***********
On 20 December 2000 the MPG participated in the meeting held to
report status of the effort to use on-board processed three-axis
magnetometer (TAM)data for attitude control of the UARS
spacecraft.
Daily processing of instrument Daily Activity Plans continues
with no problems. Instrument operations schedule is now complete
to 9 February 2001.
***********
CDHF
***********
Nothing received.
***********
FOT
***********
REPORTING PERIOD
This report covers 09 December 2000 (Orbit 50536, GMT Day 344) through 15
December 2000 (Orbit 50640, GMT Day 350).
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
SOLS 348/1445 50605 SOLSTICE Reset
The beta angle ranged between the angles of 22.6 degrees to 33.1 degrees for
this report period. The beta angle is now increasing towards a maximum angle
of 34 degrees on 17 December 2000 (DOY 352).
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 1.3 and 1.3 degrees C respectively. Additional battery performance data
for each battery on 08 December 2000 and 15 December 2000 are provided in
Appendix D.
The clock error ranged from Ð13.8 to 11.7 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.
¥ 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 = 35
¥ SOLS = 01
UARS Anomaly Reports initiated during this report period are listed in Appendix
E and summarized below.
¥ FOT = 01
Two (2) Anomaly Report remained OPEN at the end of this report period (see
Appendix E).
TRANSPONDER FREQUENCIES:
· Transponder A: 00/315 - 2287.496493
· Transponder B: 00/314 - 2287.498584
GROUND SYSTEM OPERATION
One (1) operational support problem 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 00/342 show the observatory data loss to be 300 hours, 01
minutes, 24.888 seconds. This shows a zero loss since the last report period.
This is a 0.39 percent data loss, which equals a 99.61 percent data capture for
the mission.
· There was no loss for this week.
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
UARS attitude control continues to be the focal point of the FOT's activities
this week. It was noticed on Monday, December 11 that the roll angle was off
by approximately 1.5 degrees; Tuesday morning 0.75 degrees of roll attitude was
taken out using a ground computed FDF solution. This seemed to correct the
attitude minimally. On Wednesday, December 12 we set the biases to pre star
tracker failure values, adjusted filter gain and noise parameters and then
preceeded to put the TAM into update mode. Biases were kept at the previous
accepted values. The filter seemed unable to converge with such a large
attitude error. The TAM was taken out of update and put back into monitor.
The rest of the day was spent on the simulator experimenting on methods to make
the filter not act so converged. Thursday, December 14, the bias and filter
noise values were changed to their limits and the TAM was put back into update.
Result were much better but still not completely understood. Friday, during
the meeting, discussions were initiated as to the possibility of a non-
orthogonality of the TAM alignment. The alignment appeared to be off by 1.5
degrees as well as a non-orthogonality issue. A best orthogonal alignment was
now to be determined which would keep the overall pointing errors minimal. This
will be discussed in detail next week and be implemented on 18 December 2000.
MEETINGS
The FOT attended a TAM Attitude Meeting on 11 December 2000.
The FOT attended a SERB Meeting on 13 December 2000.
The FOT attended a TAM Meeting on 15 December 2000.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for December 31, 2000 (DOY 366). 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 15 December 2000
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
50540 344/0640 00-705 NBTR NOOPS D-344
50547 344/1802 00-705 NBTR NOOPS D-344
50547 344/1802 00-707 NBTR NOOPS D-345
50548 344/2024 00-708 OBC Clk Adj from 0.00 to 20.6 msec/day
50555 345/0642 00-707 NBTR NOOPS D-345
50562 345/1803 00-709 NBTR NOOPS D-346
50566 346/0052 00-710 OBC Clk Adj from 20.6 to 0.00 msec/day
50570 346/0641 00-709 NBTR NOOPS D-346
50573 346/1254 00-711 OBC Clk Adj from 0.00 to -20.6 msec/day
50578 346/1944 00-713 ACS MAGMON TIME CORRECTION
50578 346/1944 00-714 ACS TAM ERROR VARIANCE
50578 346/2026 00-712 NBTR NOOPS D-347
50580 346/2345 00-715 OBC STATBUF RESET
50585 347/0646 00-712 NBTR NOOPS D-347
50587 347/1007 00-716 OBC Clk Adj from -20.6 to 0.00 msec/day
50589 347/1336 00-717 ACS ATTITUDE OFFSET
50590 347/1443 00-719 ACS BIAS RESET
50592 347/1805 00-718 NBTR NOOPS D-347
50594 347/2207 00-720 OBC Clk Adj from 0.00 to 20.6 msec/day
50596 348/0130 00-719 ACS BIAS RESET
50597 348/0244 00-719 ACS BIAS RESET
50598 348/0321 00-719 ACS BIAS RESET
50598 348/0426 00-719 ACS BIAS RESET
50599 348/0606 00-719 ACS BIAS RESET
50600 348/0746 00-719 ACS BIAS RESET
50604 348/1300 00-719 ACS BIAS RESET
50605 348/1445 00-719 SOLS SOLSTICE RESET
50606 348/1706 00-719 ACS BIAS NOISE
50607 348/1806 00-719 NBTR NOOPS D-349
50614 349/0607 00-724 OBC Clk Adj 20.6 to 0.00 msec/day
50615 349/0747 00-723 NBTR NOOPS D-349
50619 349/1342 00-725 ACS TAM UPDATE
50621 349/1628 00-726 ACS TAM NOISE
50622 349/1807 00-727 NBTR NOOPS D-350
50630 350/0650 00-727 NBTR NOOPS D-350
50637 350/1808 00-728 NBTR NOOPS D-351
_______________________________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 15 December 2000
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 15 December 2000
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
50548 344/2025 Clk Adj from 0.00 to 20.6 msec/day
50566 346/0100 Clk Adj from 20.6 to 0.00 msec/day
50573 346/1257 Clk Adj from 0.00 to -20.6 msec/day
50587 347/1009 Clk Adj from -20.6 to 0.00 msec/day
50594 347/2212 Clk Adj from 0.00 to 20.6 msec/day
50614 349/0611 Clk Adj from 20.6 to 0.00 msec/day
_______________________________________________________________________________
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 15 December 2000
08 Dec 2000 - GMT Day 343 Beta = 19.8 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 +728.0/+728.0 -3.68/-4.94 +0.0/+0.0 14.2 0.000 0.0
2 +5.6/-100.8 +5.15/+4.51 +29.6/-13.2 25.1 1.020 21.0
3 +44.8/-11.2 +3.87/+2.92 +28.8/-13.6 25.1 1.020 21.0
15 Dec 2000 - GMT Day 350 Beta = 33.1 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 -3.05/-4.31 +0.0/+0.0 14.2 0.000 0.0
2 +16.8/-44.8 +5.79/+4.51 +28.8/-15.2 25.0 1.050 21.0
3 +22.4/-112.0 +4.51/+3.23 +28.8/-15.2 25.0 1.040 21.0
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
---- ---- ---------
no changes V/T 5
_______________________________________________________________________________
APPENDIX E
UARS ANOMALY REPORTS
Week ending 15 December 2000
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
00-056 FOT 50584 347/0502 23302 Premature LOS. 4:57 n/rec
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
00-047 FOT see list Nov 00 14170 Generic Late Acq.
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
------ ------ ----- ---- --- -----------------
00-053 FOT 50168 319/1113 23157 Late Acquisition
00-054 FOT 50280 326/2147 23187 RESET PTP /2:39 32K
00-056 FOT 50584 347/0502 23302 Premature LOS.
SEVNTFW00/50