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UARS WEEKLY STATUS REPORT - 28 June 2002
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SOLSTICE
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Other than day only operations in support of the yaw maneuver this week,
SOLSTICE performed our nominal set of solar observations.
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SUSIM
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Nothing received.
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ACRIM
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Nothing received.
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PEM
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PEM continues to work with the GUVI team on the diagnosis of data from
the first conjunction period.
PEM has been working with the GUVI team to identify a second time period
for coordinated measurements. Predictions show the best time of conjunction
is just after the UARS YAW at the end of June; however, the spacecraft power
my not be sufficient to operate PEM. The orbital conditions are different
from the first period where the TIMED-UARS orbits are nearly perpendicular at
this time. PEM operations is requested to begin three orbits prior to and
last for three orbits after conjunction times. Predicted orbital conjunctions
as of June 21 (varies with each new set of predictions) are:
STK
Contact # Date Day Time Geo Lat ILAT MLT Hemisphere Note
(deg) (deg) (hr)
1 June 24 175 00:28 -56.98 66.07 13.11 South No UARS Power
2 June 24 175 01:17 56.75 56.31 0.95 North No UARS Power
3 June 28 179 18:42 56.54 52.83 22.83 North
4 June 28 179 19:30 -56.50 51.54 12.15 South
5 July 3 184 12:07 55.83 49.55 21.07 North
6 July 3 184 12:56 -54.66 42.80 9.07 South
7 July 3 184 13:44 54.58 49.11 21.67 North
8 July 8 189 06:21 -53.28 55.44 7.18 South
9 July 8 189 07:09 53.18 51.21 19.64 North
10 July 8 189 07:57 -53.07 52.69 7.35 South
11 July 13 194 01:22 -51.31 63.39 6:40 South
12 July 13 194 02:11 49.22 59.51 19.57 North
13 July 13 194 02:59 -49.08 58.03 6.57 South
14 July 17 198 20:24 -47.87 59.50 7.29 South
15 July 17 198 21:12 47.72 50.49 19.51 North
16 July 17 198 22:00 -47.57 61.69 6.67 South
As dates of predicted orbital elements improve, contacts appear and disappear
from this list; however, in general the conjunctions seem to be occurring at
higher latitudes later in the measurement time period (higher latitude
contacts increase the chance for adequate precipitation to produce a common
signal), This is opposite to the early contact predictions for this conjunction
time period.
PEM continues to receive NMC data files from NOAA. No problems have
been encountered.
*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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HRDI continues to function normally, making wind measurements during
the sunlit parts of orbits nearly every day, and measuring nighttime winds
when power is available.
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WINDII
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Nothing received.
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MPG
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The MPG continues to serve as the point-of-contact for UARS
instrument operations to support re-engineering of the UARS
Mission Operations Concept to develop capabilities for the
Science Traceability Mission.
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 15 June 2002 (Orbit 58836, GMT Day 166) through 21
June 2002 (Orbit 58941, GMT Day 172).
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
HALOE 168/0409 58868 POWER OFF
SUSIM 170/2051 58909 POWER OFF
SOLSTICE 170/2116 58909 POWER OFF
PEM 170/2116 58909 POWER OFF
A Reverse-to-Forward Yaw Around maneuver (number 110) was successfully
executed in Orbit 58938 beginning 172/19:44:49Z and completing at
172/20:21:59Z on 21 June 2002. All instruments were in their off or
standby mode (including HRDI and PEM). Due to the SA position at 269
degrees, the effective night length of the spacecraft after the
maneuver was approximately 56.2 minutes. Post maneuver analysis of
data indicate that during the Yaw Around, the end-of-night load bus
voltage was 26.1 volts and the average depths of discharge (DODs) on
Batteries 2 and 3 were approximately 20.41 and 20.32 percent
respectively. The next (forward-to-reverse) YAW is scheduled for 02
August 2002 (DOY 214).
The beta angle ranged between the angles of 21.4 degrees to 3.7
degrees for this report period. The beta angle is now decreasing
towards a maximum angle of 79 degrees on 13 July 2002 (DOY 194).
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 0.96 to 1.27 degrees C. Additional
battery performance data for each battery on 14 June and 21 June 2002
are provided in Appendix D.
The clock error ranged from -13.8 to 5.6 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.
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 = 03
HALOE = 01
SUSIM = 01
SOLSTICE = 02
PEM = 01
HRDI = 01
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
FOT = 01
Three (3) Anomaly Reports remained OPEN at the end of this report
period (see Appendix E).
GROUND SYSTEM OPERATION
One (1) 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
The FOT is in the process of implementing some minor changes to the
Eclipse system to help optimize operations. The new software release
is scheduled to be moved to operations on 24 June 2002.
The FOT awaits a decision regarding opening firewall rules for the new
TAC systems on the new UARS subnet. This is necessary to move the TAC
replacement systems out of building 14 and into the control center.
MEETINGS
-None this report period
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw slew is scheduled for 02 August 2002 (DOY 214).
This maneuver will be a Forward to Reverse Flight maneuver (Northern
Hemisphere viewing).
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 21 June 2002
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ ------
58868 168/0409 02-210 HALOE POWER OFF
58909 170/2051 02-211 SUSIM POWER OFF
58909 170/2116 02-212 SOLSTICE POWER OFF
58909 170/2116 02-213 PEM POWER OFF
58912 171/0145 02-214 HRDI LOW POWER MODE
58917 171/1022 02-215 SOLSTICE DAY ONLY MUB DISABLED
58922 171/1742 02-216 OBC/CLK CLK ADJ 0.00 TO 20.6 MSEC/DAY
58924 171/2115 02-217 OBC/CLK CLK ADJ 20.6 TO -20.6 MSEC/DAY
58937 172/1704 02-218 MACS YAW TO FWD FLT; VT-5 TO VT-6
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 21 June 2002
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 21 June 2002
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ----- -----------------
58922 171/1742 CLK ADJ 0.0 TO 20.6 MSEC/DAY
58924 171/2115 CLK ADJ 20.6 TO -20.6 MSEC/DAY
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 14 June 2002
14 June 2002 - GMT Day 165 Beta = 25.6 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 +00.0/+00.0 9.4 0.000 0.0
2 +11.2/-100.8 +5.47/+4.51 +28.0/-14.4 24.6 1.020 20.7
3 +22.4/-050.4 +4.51/+3.23 +27.2/-14.0 24.5 1.020 20.4
21 June 2002 - GMT Day 172 Beta = 3.7 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 -3.68/-4.62 +00.0/+00.0 9.4 0.000 0.0
2 +11.2/-089.6 +5.15/+4.19 +27.2/-14.4 24.5 1.010 20.5
3 +22.4/-044.8 +4.19/+2.92 +26.4/-14.0 24.5 1.010 20.3
V/T LEVEL CHANGES
ORB# AOS TIME LVL FR-TO
----- -------- ---------
58937 172/1704 L5 -> L6
APPENDIX E
UARS ANOMALY REPORTS
Week ending 21 June 2002
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
02-037 FOT 58927 172/0223 N/A Data Dropout CDS#30824
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
02-036 FOT See List June 01 N/A Generic Late Acquisition
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
------ ------ ----- ---- --- -----------------
02-033 FOT 58553 147/0359 N/A SSPP IN WAIT MODE/PLANNING ERR
02-035 FOT 58719 158/0606 44490 WSGT EQUIP PROBLEMS
02-035 FOT 58720 158/0746 44490 WSGT EQUIP PROBLEMS
02-037 FOT 58927 172/0223 N/A Data Dropout CDS#30824