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UARS WEEKLY STATUS REPORT - 15 MAY 1998
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SOLSTICE
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SOLSTICE continues to operate normally, collecting solar data on all
available orbital tracking periods and stellar calibration observations,
whenever possible.
SOLSTICE delivered v. 4.60 of its processing software to CDHF this week,
and testing is underway. This version is a major revision, with significant
improvements in many of our processing and calibration algorithms, and we
expect that the new versions (data version 10) of our final science products
will also be significantly improved.
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SUSIM
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SUSIM has successfully gathered its normal solar, offset, and
occultation scan data without apparent problems.
A new version of an SUSIM MgII index, V19r3, is now available through
SUSIM's WWW site. The new index correlates with V19r2 at about 0.995.
See:
http://wwwsolar.nrl.navy.mil/susim_uars_mgii_index.html
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PEM
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PEM/AXIS became active on May 10. It is currently generating energy
deposition from inverted X-ray spectra for each of its 16 look directions.
GSFC has proposed an OBC operation plan for the activation of PEM boom
instruments during the daylight portions of every orbit. This OBC operation
plan is under evaluation by PEM. PEM has proposed a series of test procedures
for activation and is waiting response from GSFC.
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HALOE
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Nothing received.
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MLS
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The MLS instrument has been powered off since May 2. MLS is scheduled to
begin south viewing operations on May 20.
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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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Routine processing of instrument Daily Activity Plans continues
with no other 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 notified users about the installation of UCSS release 10.0.
The build has been scheduled for May 27th and should require about 10 hours of
downtime during day shift. Users were requested to send comments, reservations,
or impact statements to the PAC account.
The CDHF has received a total of 388 CD-ROM requests as of 15-May-1998.
Two orders were received and shipped.
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.
26 days PEM (3.32) PROD (1379R-1238C=141L)
67 days HAL (4.80) PROD (L1) (1868R-67C-1F=1800L)
The CDHF added a javascript file to our web server which routes users looking
for the UARS Science web pages to the UMPGAL server.
CDHF pending software upgrades: IDL 5.1, OpenIngres, UCSS.
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FOT
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REPORTING PERIOD
This report covers 02 May 1998 (Orbit 36273, GMT Day 122) through 08 May
1998 (Orbit 36378, GMT Day 128).
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
MLS 122/2330 36288 Off
The beta angle is now decreasing toward a minimum angle of 0.0 degrees on
05 May 1998 (DOY 125).
A Reverse-to-Forward Yaw Around maneuver (number 68) was successfully
executed in Orbit 36327 at 14:20:20 UTC on 05 May 1998. The SSPP
Instruments (ACRIM, SOLSTICE, and SUSIM) were enabled. Due to the SA
position at 269 degrees, the effective night length of the spacecraft after
the maneuver was 48 minutes. Post maneuver analysis of data indicate that
during the Yaw Around, the end-of-night load bus voltage was 24.5 volts and
the average depths of discharge (DODs) on Batteries 2 and 3 were
approximately 22.5 and 22.0 percent respectively.
Two manually generated SSPP Stellar Offset experiments requested by
SOLSTICE operations were performed on GMT days 125 and 127
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 24.6 V end-of-night (EON) load bus
voltage. Battery temperatures are stable with a temperature delta between
Battery 2 and Battery 3 of 1.3 degrees C. Additional battery performance
data for each battery on 02 May 1998 and 08 May 1998 are provided in
Appendix D.
The clock error ranged from -10.8 to +0.6 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 = none
% OUT-OF-LIMITS = 05
The following real-time command sheets were executed for the listed
operational element(s) during this report period (see Appendix A).
% FOT 01
% MLS 01
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
% FOT 01
One (1) Anomaly Reports remained OPEN at the end of this report period (see
Appendix E).
TRANSPONDER FREQUENCIES:
Transponder A: 98/062 - 2287.496945
Transponder B: 98/062 - 2287.497010
GROUND SYSTEM OPERATION
No (0) operational support problem(s) 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 98/127 show the observatory data loss to be
20 hours, 43 minutes, 11.156 seconds (an increase of 2.368 seconds since
last report period). This is a 0.0357 percent data loss which equals a
99.9643 percent data capture for the mission.
The increase of 2.368 seconds occurred over a four day period:
0.922 seconds on Day 122 due to hits in the data,
0.224 seconds on Day 124 due to hits in the data,
0.576 seconds on Day 125 due to hits in the data, and
0.576 seconds on Day 125 due to hits in the data.
All missing level-0 data resulting from the Building 23 power outage was
processed by about noon on 04 May 1998. The data loss calculations were
included in the report for last week.
The FOT experienced along track transition comparisons in excess of 1.5 km
when processing the ephemeris on the CMS this week. The out-of-limit
comparisons occurred on all three of the ephemeris delivery days. FOT
contacted the FDF representative regarding his analysis of the need to
transition to a more frequent ephemeris delivery. The FDF representative
stated that due to the upcoming increase in solar flux, FDF will need to
start providing a daily ephemeris solution to the FOT beginning sometime in
the next few weeks.
The FOT did not perform any IP testing this week. All efforts are being
directed to database development to support the planned OBC Flight Software
update.
The FOT finished the preliminary modifications to the OBCSTF resident POCC
database this week. Database version 67 was generated and delivered (on
tape) to the MSOCC software coordinator (Huong Truong) on 07 May 1998. The
MSOCC software coordinator will process database on the AP and install it
onto PE 49 (E.Z. BlockUs test pack). The FOT will spend the next several
weeks testing database 67 and making any necessary corrections.
OTHER SIGNIFICANT EVENTS
Work on the upgrade of the OBC Power Monitor (PMON) continued. Tested the
programmers version of the new AP software with database 66 (test database,
not the new database) on Thursday, 07 May. All features worked as
expected. Began testing of the new flight software with the new database.
Found a few minor problems with the database, and a telemetry formatting
problem in the flight software (now corrected). Testing will continue this
week.
Work continues on the UARS August orbit adjust planning, The Branch Head of
the Propulsion Branch (Dennis Asata), informed the FOT that analytical
analysis of the UARS hydrazine pipe refill showed a peak pressure
calculation of 1500 psi. This pressure, though not zero risk, should be
safe with the exception that the pressure transducer may change scale due
to the pressure surge. He indicated that a test with a latch valve should
be performed to confirm the calculation.
FOT continues to support CNMOS in their efforts to make necessary software
changes (MSOCC, CMS, DCF, etc.) to support the year 2000 rollover.
Monitoring of the magnetic field model performance continues.
FOT continues to improve a Power Profile for UARS based on the current
status of the Modular Power System.
FOT continues to support the new UARS ground system re-engineering effort.
A response to a list of questions was prepared for distribution this week.
MEETINGS
No UARS Battery telecon was held this week. The next telecon has not been
scheduled.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw Around Maneuver is currently scheduled for 16 June 1998.
The UARS orbit altitude is dropping slowly and a drag makeup orbit adjust
is targeted for 05 August 1998.
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 08 May 1998
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ -------
36288 122/2330 98-156 MLS Power OFF
36288 122/2330 98-157 OBC Clk Adj 20.6 to 0.00 msec/day
_______________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 08 May 1998
MNEMONIC STATE DESCRIPTION ORBITS
--------- ----- ------------ ------
HRPTSPBIMON Y-HI PTS Pulse Bus Current Monitor 36171,235,39
QTSISAIF Y-HI SSPP Baseplate by SISA I/F 36281,94,96,309-
18,24,39-40,42,46,53-
63,69
WIEUTEMP Y-LO WINDII EU Temperature 36302,03,04-64,69-78
SOSTMPRNTRN Y-LO Temperature Entrance 36327,39,42,53-54,58-
59,69
SOSTMPRBLFT Y-LO Temperature Bot_Left_Front 36339,
ACTEMPANA1 Y-LO Temp PCU Board 1 36342,44,64
The following ALERT occurrences were detected:
MNEMONIC DESCRIPTION ORBITS
--------- ------------ ------
None this report period
APPENDIX C
CLOCK & SOLAR ARRAY RATE CORRECTIONS
Week ending 08 May 1998
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ---- -----------------
36288 122/23:37 (02 May 98) from 20.6 to 00.0 msec/day
_______________________________________________________________
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 08 May 1998
02 May 1998 - GMT Day 122 Beta = 13.5 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 +728.0/+728.0 -2.73/-3.68 +0.0/ +0.0 18.4 0.000 0.0
2 +39.2/ -5.6 +7.41/+5.79 +32.0/-15.2 23.8 1.018 24.0
3 +39.2/ -16.8 +6.11/+4.51 +31.2/-16.0 23.7 1.021 23.3
08 May 1998 - GMT Day 128 Beta = 10.8 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 18.4 0.000 0.0
2 +89.6/ -5.6 +5.15/+3.87 +30.4/-13.2 25.8 1.024 21.5
3 +56.0/ -11.2 +3.87/+2.60 +29.2/-14.4 25.8 1.021 20.8
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- -------- ----------
no changes
APPENDIX E
UARS ANOMALY REPORTS
Week ending 08 May 1998
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
98-023 FOT 36274 122/0050Z N/A TAC #2 Crashed
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
98-022 FOT 36272 121/21:36 TAC 2 CRASH
98-023 FOT 36274 122/00:50 TAC 2 CRASH
ANOMALY INVESTIGATION REPORTS GENERATED
AIR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------- ------ ----- ---- --- -----------------
None this report period
OPEN ANOMALY REPORTS
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
98-021 Generic Late Acq for May 1998 (Open until 31 May 1998).
SEVNTFW19