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UARS WEEKLY STATUS REPORT - 30 SEP 2005
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SOLSTICE
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Nothing received.
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SUSIM
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Nothing received.
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PEM
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HEPSA data files are version 2. Currently, HEPSA data between 1991274
and 2004273 has been reprocessed and archived at the GSFC DAAC. HEPSA data
between 2004274 and 2005099 has been processed and is waiting for archival
at the DAAC.
MEPS data files are version 1. Processed MEPS data files at the DAAC
archive are between 1991274 and 2004259. MEPS data between 2004260 and
2005099 has been processed and is waiting for DAAC archival.
HEPSB data files are version 1. HEPSB data files between 1991274 and
1991366 have been processed and are waiting for DAAC archival.
Processing of all PEM DAAC data files has been suspended until the
DAAC catches up with archiving all processed data files. It was discovered
that DAAC changed the access IP node. This caused failure accessing SwRI
to retrieve Level 2 data. A change order at SwRI has been initiated.
Tests of the AXIS1 data file formats have been successful. The AXIS1
format design has been coded. A test file has been generated. A check
program with processing scripts have also been generated. Example binary
read program is complete and verified. These results have been sent to
the project. Creation of the AXIS1 data documents for DAAC data will
begin shortly.
PEM continues to receive NMC data files from NOAA. No problems have
been encountered since updates have occurred.
The PEM data from the GUVI conjunction periods may be found at
http://wwwpem.space.swri.edu/guvi-pem.html. The additional electron data for
the October and November storms of 2003 has been moved and is now located at
http://climatology.space.swri.edu/uars_fromRudy.html. For those users of
SDDAS, update your UARS Meta data and these data times will appear
with full functionality. Proton data from these storms are now located at
http://climatology.space.swri.edu/UARS_images_from_Rudy_(Apr._2004).html
Requests have been received for storm spectral data. Overview plots were
produced and these plots may be found on the web at
http://climatology.space.swri.edu/UARS_images_postedJune2004.html
for the storms of October 29 of 1991, November 8-9 of 1991, April 6-7 of 2000,
March 31 - April 1 of 2001, April 11-12 of 2001, November 6-7 of 2001, and
November 11-12 of 2001.
PEM has received a request for data from the super storm of November
2004. The Dst value showed sudden commencement early on November 7, 2004
reaching a Dst value of about -380 gamma early on November 8, 2004.
PEM was not active at that time and became active late on November 8, 2004
in day only mode. A second peak of about -280 gamma was observed on November
11, 2004. PEM became active in day-light only mode late on November 8. PEM
survey spectrograms for November 8-18 of 2004 may be found at:
http://climatology.space.swri.edu/UARS_images_fromRudy.html
*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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Nothing received.
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MLS
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Nothing received.
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HRDI
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Nothing recieved.
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MPG
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The MPG is participating in the on-going UARS end of mission
planning activities.
The MPG continues to serve as the point-of-contact for UARS
instrument operations in support of the Science Traceability
Mission of UARS.
Daily 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 17 September 2005 (Orbit 76716, GMT Day 260)
through 23 September 2005 (Orbit 76836, GMT Day 266).
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
-NONE THIS REPORT PERIOD
A Forward-to-Reverse Yaw Around maneuver (number 143) was successfully
executed in Orbit 76740 beginning 260/ 14:47:03Z and completing at
260/ 15:24:13Z on 17 September 2005. All instruments were in their
off or standby mode. Due to the SA position at 265 degrees, the
effective night length of the spacecraft after the maneuver was
approximately 59.80 minutes. Post maneuver analysis of data indicate
that during the Yaw Around, the end-of-night load bus voltage was
24.00 volts and the average depths of discharge (DODs) on Batteries 2
and 3 were approximately 8.85 and 31.57 percent respectively. The
next (reverse-to-forward) YAW is scheduled for 24 October 2005 (DOY
297).
The beta angle ranged between the angles of 02.1 degrees to 24.1
degrees for this report period. The beta angle is now increasing
towards a maximum angle of 62 degrees on 6 October 2005 (DOY 279).
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 23.6 V end-of-night (EON) load bus
voltage. Battery temperatures are stable with a temperature delta
between Battery 2 and Battery 3 of 10.6 to 9.2 degrees C. Additional
battery performance data for each battery on 16 September 2005 and 23
September 2005 are provided in Appendix D.
The clock error ranged from 10.5 to -10.9 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 = 14
HALOE = 01
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 03
Two (2) Anomaly Reports remained OPEN at the end of this report period
(see Appendix E).
GROUND SYSTEM OPERATION
Three (3) operational support problems occurred this period. Anomaly
Reports are included in Appendix E.
The data loss calculations are no longer being supplied by Data
Capture Facility (DCF).
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
This week the FOT continues to closely monitor the condition of
battery 2 and battery 3. Battery 2 and 3 have not been sharing load
well since the cell failure on battery 2. Battery 3 now carries
almost 90% of the power load while battery 2 provides the remaining
10%. The orbits leading up to the yaw were of greatest concern as the
EON load bus voltage was low due to the beta angle. NASA power branch
has been providing daily support in monitoring the UARS battery
condition. The FOT has been authorized to disable all platform and
instrument heaters on the SSPP. This will be done at the earliest
available opportunity.
The FOT completed the planned repeat 30-second burn on 19 September
2005. The burn started as planned at 262/1455 and terminated 30
seconds later. Preliminary analysis showed that the BIAS that was
selected allowed the attitude control thrusters to come on sooner and
the translation thrusters came back on with several seconds left in
the 30-second burn. The FOT also saw the translation thrusters off-
pulse as planned. This engineering burn performed as expected with no
surprises.
The success of the 2nd 30-second burn cleared the way for the final
planned engineering burn of 2 « minutes on 22 September 2005. The
primary goal of this burn was to see the spacecraft achieve steady
state with all 4-translation thrusters firing. The burn started as
planned at 265/1459 and terminated 150 seconds later. Post-burn
analysis showed that UARS achieved steady state approximately 35 to 40
seconds into the burn. The initial transient was almost identical to
the earlier 30-second burn that was done on 19 September 2005. The
individual thruster duty cycles were A [59.0%]; B [50.8%]; C [89.1%];
D [89.0%]. After the initial transient, translation thrusters C and D
operated at 100% duty cycle. The overall duty cycle for this 150-
second burn was 72%. While this is lower than the predicted 90% that
was used to plan out the burn schedule for UARS, it will increase and
asymptotically approach 80% as the burns increase in length.
The FOT has been directed to stand down from the first planned orbit
lowering burn on 29 September 2005 by NASA headquarters. This stand
down order, coupled with the slightly reduced duty cycle of the UARS 4-
thruster mode will mean that the FOT will not be able to keep to its
plan of de-orbiting UARS as quickly as possible due to the cell
failure on battery 2. The earliest that the FOT will be able to
completely expend all the hydrazine onboard will be sometime in early
to mid December.
MEETINGS
The FOT attended a De-boost status meeting / CAM this week on 19
September 2005. There were no concerns raised at the CAM, and the FOT
was given permission to proceed with the calibration burn on 19
September 2005.
The FOT attended the UARS End of Mission Peer Review on 21 September
2005. One RFA came out of the review. The RFA was to document waive
off and abort criteria for the long duration burns for both an ACS
perspective and a collision avoidance perspective.
The FOT attended another CAM on 21 September 2005. The FOT presented
two procs that would be used instead of manual commanding to help
reduce the time needed to setup for a burn. The proc and contingency
commands were reviewed. There were no concerns raised with using
procs instead of manual commanding for the 2 « minute burn on 22
September 2005.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for 24 October 2005 (DOY 297).
This maneuver will be a Reverse to Forward Flight maneuver (Southern
Hemisphere viewing).
The FOT has been directed to stand down from our first scheduled 18-
minute burn by NASA HQ. The burn was scheduled for 29 September 2005,
and has been canceled. UARS is still go for executing the scheduled
18-minute burn on 04 October 2005 and 06 October 2005.
Attachments: Appendix A, Real-time Command 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 23 September 2005
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
76738 260/1213 05-332 MPS VT L6 TO L7
76739 260/1353 05-333 MACS YAW - FWD TO REV
76741 260/1632 05-334 OBC BANK DUMPS
76755 261/1544 05-335 HALOE RESTOWED - REV
76769 262/1315 05-336 MACS ENG BURN - STEP 1
76770 262/1402 05-336 MACS ENG BURN - STEP 3,5,6
76770 262/1445 05-336 MACS ENG BURN - STEP 7-24
76773 262/1940 05-337 OBC OPEN EPHEM THRESHOLD / LOADS
76774 262/2057 05-337 OBC DEFAULT EPH THRESHOLD
76774 262/2158 05-338 OBC CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
76775 262/2339 05-339 OBC ATC NOOP
76797 264/0920 05-340 OBC CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
76814 265/1258 05-341 PM ENGINEERING BURN 2:30 - STEP 1
76814 265/1351 05-341 PM ENG BURN - STEP 3,4,5
76815 265/1453 05-341 PM ENG BURN - STEP 6-23
76816 265/1616 05-343 MPS VT LEVEL 7 TO LEVEL 6
76816 265/1616 05-342 OBC EPHEM REJECT CORRECTION
76818 265/2006 05-344 OBC POST-BURN EPHEM LOAD
76819 265/2149 05-345 OBC ATC NOOP XMTR ON
76817 265/1745 05-342 OBC DEFAULT EPHEM TOLERANCE
76823 266/0326 05-346 MPS VT L-6 TO VT L-7
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 23 September 2005
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 23 September 2005
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
76774 262/2202 CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
76797 264/0922 CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 23 September 2005
16 September 2005 - GMT Day 259 Beta = 06.7 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 -2.42/ -3.68 +00.0/+00.0 04.6 0.00 0.0
2 -700.0/-700.0 +3.87/ -0.23 +21.6/-13.6 24.3 1.03 7.1
3 067.2/-033.6 +8.07/ +7.09 +49.6/-22.8 24.2 1.01 28.5
23 September 2005 - GMT Day 266 Beta = 24.1 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 -1.79/ -3.05 +00.0/+00.0 04.6 0.00 0.0
2 -700.0/-700.0 -0.54/ -1.79 +16.8/-06.8 26.4 1.05 3.7
3 067.2/-056.0 +10.06/ +7.41 +50.4/-25.0 26.4 1.03 29.2
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
76738 260/1213 L6 -> L7
76816 265/1616 L7 -> L6
76823 266/0326 L6 -> L7
APPENDIX E
UARS ANOMALY REPORTS
Week ending 23 September 2005
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
05-044 FOT 76773 262/1940 30832 Generic Late Acquisition
05-044 FOT 76774 262/2158 30832 Generic Late Acquisition
05-044 FOT 76803 264/2009 30832 Generic Late Acquisition
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
-None this report period.
ANOMALY INVESTIGATION REPORTS GENERATED
AIR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
-None this report period.
OPEN ANOMALY REPORTS
AR NO. SUBSYS ORBIT TIME CDS PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
05-042 MPS 76339 233/2347 N/A BATTERY 2 DIFFV -700mV
05-044 FOT See List Sept 05 30832 Generic Late Acquisition