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UARS WEEKLY STATUS REPORT - 12 NOV 1999
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SOLSTICE
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Other than the obvious loss of data due to tape recorder problems this week,
SOLSTICE continues to operate 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 is operating, but data collection continues to be affected by
telemetry outages. Although scheduled operations went as planned this
weekend, very little data was received when the tape recorder resumed
its misbehavior. Since then, planning to take advantage of TDRS
contacts is expected to improve the data coverage.
Increased telemetry time provided by extra TDRS contacts is helpful, but
is more effective when TDRS contact times are available in a timely
fashion during the instrument operations planning cycle. We are working
with the MPG and FOT planners to expedite this improvement.
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ACRIM
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ACRIM II continues to operate normally. Multi-sensor comparisons indicate
continuing calibration stability of the total solar irradiance (TSI) monitoring
sensor.
Routine monitoring was switched from sensor B to A in late October. The set
point of sensor A provides higher servo loop gain for perihelion TSI levels. No
significant impact on the TSI database is predicted.
An algorithm update developed in 1999 is being used to refine the ACRIM II TSI
data products. Substantial additional raw data have been found for recent years
in the UARS archives at CDHF2 relative to that in the originally posted data
files. A new version (ver. 1999) of all data products will be archived soon on
the acrim web page (acrim.com) and at the NASA GSFC and LaRC DAAC's.
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PEM
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The PEM spectrometers continue to be active under PMON control* and are
not affected by the current spacecraft power restrictions. The PEM/AXIS
operation was affected and was not activated as scheduled. While under PMON
control, the PEM instrument computed energy deposition from electrons and
protons measured in-situ by the particle spectrometers.
Geoff Crowley represented PEM at the UARS science team meeting in
Virginia Beach, October 26-28. Dr. Crowley presented the PEM status, a paper
titled "Simulation of the Solstice Mesopause" (G. Crowley, G. Thomas R. Roble,
J. Olivero, and H. Liu), and a poster titled "Climatology for Studying the
Effects of Particles on the Atmosphere" (R. Frahm, J. R. Sharber,
J. D. Winningham, G. Crowley, A. J. Ridley and R. Link).
*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 continued successful operations until it was turned off Wednesday,
November 10, 199 at approximately 14:00 GMT in preparation for the upcoming
solar graze. HALOE will be off until November 25th.
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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 is on, and operating normally. The data gaps evident at
the beginning of the operating period are now no longer significant.
Operation is scheduled to continue until November 14.
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MPG
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Routine processing of instrument Daily Activity Plans continues
with no problems. The MPG continues to assist the Project
Scientist with the scheduling of instrument operations.
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CDHF
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The CDHF continues to notify PI Software Representatives regarding data
gaps in the LEVEL0 data that occurred as a result of the UARS Tape Recorder
Anomaly.
The CDHF processed current day data through level 3 for all active
instruments. Additionally, CDHF personnel reprocessed: (R)= Requested
(C) = Complete, (F)= Failed (L) = Days remaining to reprocess.
19 days CLA (7.0) PROD (L1-L3) (476R-374C-17F=85L)
25 days GPI (4.05) PROD (CLAES L3B) (307R-285C-1F=21L)
3 days WIN (5.11A) PROD (L1-L3) (TEST) (3R-3C=0L)
The CDHF has successfully tested WINDII V5.11A formal software delivery.
Currently waiting further instructions.
DAAC DATA
- DAAC data through August 1999 is available to the User Community for
HALOE, PEM, NMC, and UKMO.
- Data created in the month of February 1999 has been loaded into the
DAAC Transfer Tables for SUSIM LEVEL 3BS (Output 20). DAAC has been
notified.
UARS CDHF REHOST:
We are preparing to test SUSIM V7.1 on the Rehost System.
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FOT
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REPORTING PERIOD
This report covers 30 October, 1999 (Orbit 44450, GMT Day 303) through 5
November 1999 (Orbit 44555, GMT Day 309).
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
HALOE 305/0027 44480 On
HALOE 305/0909 44486 Off
HALOE 308/2259 44539 On
WINDII 309/2211 44554 On
The beta angle ranged between the angles of 0.8 degrees to 30.3 degrees for
this report period. The beta angle is now increasing toward a maximum angle of
76 degrees on 18 November 1999 (DOY 322).
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 29 October 1999 and 05 November 1999 are provided in Appendix D.
The clock error ranged from -10.3 to 11.6 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.
% ALERTS = 00
% OUT-OF-LIMITS = 01
The following real-time command sheets were executed for the listed operational
element(s) during this report period (see Appendix A).
% FOT = 10
% HALOE = 05
% WINDII = 01
% SUSIM = 01
UARS Anomaly Reports initiated during this report period are listed in Appendix
E and summarized below.
% FOT = 08
Two (2) Anomaly Reports remained OPEN at the end of this report period (see
Appendix E).
TRANSPONDER FREQUENCIES:
% Transponder A: 99/263 - 2287.496947
% Transponder B: 99/265 - 2287.498700
GROUND SYSTEM OPERATION
Three (8) 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 99/308 show the observatory data loss to be 83 hours, 55
minutes, 51.673 seconds (an increase of 0.384 seconds since the last report
period). This is a 0.1180 percent data loss which equals a 99.8820 percent
data capture for the mission.
The increase of 52 hours 11 minutes 43.064 seconds occurred over three (6)
days:
7 12 hours 15 minutes 8.408 seconds on Day 303 due to a S/C TR problem.
7 17 hours 48 minutes 41.184 seconds on Day 304 due to a S/C TR problem.
7 17 hours 37 minutes 55.456 seconds on Day 305 due to a S/C TR problem.
7 02 hours 56 minutes 34.240 seconds on Day 306 due to a S/C TR problem.
7 00 hours 56 minutes 53.216 seconds on Day 307 due to a S/C TR problem.
7 00 hours 36 minutes 30.560 seconds on Day 308 due to a S/C TR problem.
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
The Flight Operations Team (FOT) presented a plan to safe the spacecraft in the
event of an attitude anomaly with the On Board Computer running. This plan was
presented in several parts. First, a quick fix that may be implemented prior
to Y2K. Second, additional modifications to cover the different types of
failure scenarios. Third, an expanded, more detailed review of the safehold
and operating hardware to provide the best possible safety net available based
on available hardware. The support engineers were asked to review the plan in
more detail on their own time and provide relevant input as determined. They
were also asked to continue to work on the various concepts presented during
this and the previous meeting for handling an OBC halt. The FOT will
correspond with each engineer on a bi-weekly basis. When significant progress
has been made or new concepts need to be discussed a meeting will be scheduled.
It is the intent of the FOT to hold another meeting prior to Y2k.
Investigation continues with NBTR B. Testing has been on going this week in an
attempt to determine the nature of anomaly. The significant accomplishments
towards the resolution of this anomaly up through Friday, November 5 are the
following:
1. Review a history of NBTR B plots and telemetry, current and back to 5
years prior.
- No obvious signatures observed in processed NBTR B data or real-time
history.
- Failure condition inhibits the capture of any recorded data during
anomalous playback.
- Raw data dumps captured at White Sands provide insight to errors
associated with tape recorder bits 6 - 8.
2. Develop Test Plan to aid in anomaly determination. Two tests completed so
far,
- A spooling test was done to relieve tension or clear debris on the
tape. This test involved the forward and reverse winding of the tape
three consecutive times and implement a record and playback sessions.
This appeared to provide short term success.
- Record on different parts of the tape to eliminate problem areas on the
tape. This test did not provide positive results.
3. Present anomaly analysis to supporting government personnel.
- Received approval to schedule all available TDRSS view periods
- Provided outside contract help with relevant experience.
YEAR 2000 OPERABILITY SUPPORT
No Y2k activities this week.
MEETINGS
DOY 305, Nov 1, 1999 - A meeting was held to discuss the status of NBTR B.
Government (TDRSS/NASA) and Subcontractors were present. The Flight Operations
Team presented its current findings and recommendations. A series of Tape
Recorder tests were delivered in the anomaly report. The tape Spooling test
was all agreed upon and executed that evening.
DOY 307, Nov 3, 1999 - The monthly meeting was held. The primary discussion
was the status of the tape recorder. Additional supporting personnel were
present. It was agreed that a Multiple Access (MA) configuration plan should
be developed and ready to be implemented. The purpose for the MA configuration
is to provide more real-time coverage to minimize the lost of Science data.
DOY 309, Nov 5, 1999 - A meeting was held to discuss the status of the UARS
Safehold configuration and to expand upon ideas presented at the previous
meeting. The Flight Operations Team (FOT) present an OBC controlled safehold
concept. This idea was generally accepted. The FOT has the action to simulate
the plan and present the results at the next Safehold configuration meeting
which is TBD.
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. It is expected that one
more meeting will be held before Y2k as an update to UARS safehold expectations
for the new century.
PERSONNEL CHANGES
None.
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 5 November 1999
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ -------
44453 303/0429 99-351 OBC Clk Adj fr 0.00 to -20.6 msec/day
44462 303/1921 99-352 NBTR NBTR NOOP'S
44463 303/2102 99-353 OBC TMON-13 Disabled
44463 303/2102 99-354 NBTR NBTR NOOP'S
44469 304/0606 99-355 OBC Clk Adj fr -20.6 to 0.00 msec/day
44470 304/0725 99-356 NBTR NBTR NOOP'S
44474 304/1317 99-357 OBC Clk Adj fr 0.00 to 20.6 msec/day
44480 305/0027 99-358 HALOE Power ON
44484 305/0555 99-359 HALOE Power ON
44486 305/0909 99-360 HALOE Power OFF LOW EONLBV
44489 305/1420 99-361 OBC Clk Adj fr 20.6 to 0.00 msec/day
44493 305/2108 99-362 SUSIM MPL Commands
44494 305/2251 99-363 NBTR TEST SEQUENCE
44497 306/0306 99-364 NBTR 5 RECORD/DUMP SEQUENCES
44539 308/2259 99-365 HALOE Power ON (Partial)
44543 309/0501 99-366 HALOE Power ON Complete
44554 309/2211 99-367 WINDII Power ON
____________________________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 5 November 1999
The following Out-Of-Limits occurrences were detected:
MNEMONIC STATE DESCRIPTION ORBITS
--------- ----- ------------ ------
NBRECBI Y-HI NBTR B Current 44544
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 5 November 1999
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ---- -----------------
44453 303/04:29 (30 Oct 99) from 00.0 to -20.6 msec/day
44469 304/06:06 (31 Oct 99) from -20.6 to 00.0 msec/day
44474 304/13:17 (31 Oct 99) from 00.0 to 20.6 msec/day
44489 305/14:20 (01 Nov 99) from 20.6 to 00.0 msec/day
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 5 November 1999
29 Oct 1999 - GMT Day 288 Beta = 0.8 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 -89.6/-112.0 -3.05/-4.31 +0.0/+0.0 16.3 0.000 0.0
2 +56.0/-5.6 +6.44/+5.15 +30.4/-14.0 23.8 1.017 22.2
3 +22.4/-100.8 +5.15/+3.87 +29.6/-14.4 23.8 1.018 21.8
05 Nov 1999 - GMT Day 309 Beta = 30.3 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 -89.6/-106.4 -3.05/-4.94 +0.0/+0.0 16.3 0.000 0.0
2 +28.0/-11.2 +5.47/+3.87 +29.6/-15.2 25.3 1.086 21.2
3 +33.6/-22.4 +4.51/+2.60 +29.2/-15.2 25.1 1.083 21.0
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- ----- ----------
no changes V/T 5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 5 November 1999
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-073 FOT 44456 303/0939 21524 No Q Chan lock 5:35 D/L
99-074 FOT 44457 303/1123 21524 No Q Chan lock 6:01 D/L
99-075 FOT 44474 304/1317 N/A TAC-8 Crashed
99-081 FOT 44521 307/1750 14170 Generic Late Acquisition
99-076 FOT 44523 307/2114 21541 Unable to do OBC Dumps
99-077 FOT 44524 307/2256 21541 No lock on I-Chan.
99-078 FOT 44524 307/2158 21541 System Pack #3 Crash
99-081 FOT 44546 309/0919 14170 Generic Late Acquisition
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-073 FOT 44456 303/0939 21524 Clos. attached to AR-071
99-074 FOT 44457 303/1123 21524 Clos. attached to AR-071
99-075 FOT 44474 304/1317 N/A TAC-8 Crashed
99-076 FOT 44523 307/2114 21541 Unable to do OBC Dumps
99-077 FOT 44524 307/2256 21541 No lock on I-Chan.
99-078 FOT 44524 307/2158 21541 System Pack #3 Crash
99-081 FOT November 14170 Generic Late Acquisition
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
SEVNTFW99/45