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UARS WEEKLY STATUS REPORT - 22 JAN 1999
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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.
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SUSIM
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SUSIM successfully gathered its normal solar, offset, and occultation
data without apparent problems.
Reprocessing of all SUSIM experiment days to version 20 continues.
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PEM
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PEM is active PMON control. Energy processor #6 for the HEPS-1 unit
has been found to not activate correctly. Data affected are from the upper
energy EE channel for Head-2 of HEPS-1 (that is the +15 deg electrons above
300 keV). Tests are being conducted on this energy processor to assure
that it is operating correctly. Measurements from this sensor will be
activated as soon as possible.
While under PMON control, the PEM instrument computes energy deposition
from the HEPS unit.
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HALOE
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Nothing received.
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MLS
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The instrument is now off as scheduled.
MLS is scheduled to begin operations on Jan 26 and operate though Feb 1. The
MLS team will operate the instrument in a mode emphasizing scientific
observations at the northern latitudes.
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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 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 all PI representatives regarding the unrecoverable data
gap for UARS DAY 2681 and the re-ingest of LEVEL0 for UARS DAY 2684 which
has better quality.
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.
0 days HAL (4.80) PROD (L3) (1874R-1721C-1F=152L)
166 days SUS (7.00) PROD (L3) (2540R-1592C-8F=940L)
The CDHF re-scheduled the migration and testing of UCSS10.1 executables
until January 25th. Notification of this effort has been
forwarded to the user community. An overview of the release notes,
has been copied to the sys$public area.
CDHF pending software upgrades: IDL 5.03, OpenIngres, UCSS 10.1, MSS 4.1,
NRT 2.5, UOAS 5.4 .
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FOT
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REPORTING PERIOD
This report covers 09 January 1999 (Orbit 40047, GMT Day 009) through 15
January 1999.
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
WINDII 010/2334 40005 Off
SSPP 011/1822 40005 FDC recov.
MACS 013/0650 40005 ESAM2 On
MACS 013/1054 40005 ESAM2 Off
PEM 013/1401 40005 Calibration
HALOE 014/2026 40016 On
The beta angle ranged between +11.6 degrees to -14.6 degrees for this
report period. The beta angle is now increasing toward a maximum angle of -
74.0 degrees on 31 January 1999 (DOY 011).
A Forward-to-Reverse Yaw Around maneuver (number 75) was successfully
executed in Orbit 40087 beginning 011/16:07:46 and completing at
011/16:44:56 on 11 January 1999. The SSPP Instruments (ACRIM, SOLSTICE,
SUSIM) were enabled as well as HRDI and PEM in day only operations. Due to
the SA position at 269 degrees, the effective night length of the
spacecraft after the maneuver was approximately 52 minutes. Post maneuver
analysis of data indicate that during the Yaw Around, the end-of-night load
bus voltage was 23.8 volts and the average depths of discharge (DODs) on
Batteries 2 and 3 were approximately 22.0 and 22.5 percent respectively.
The next (reverse-to-forward) YAW is scheduled for 20 February 1998.
A +0.5 to 0.0 Degree Roll Reset Maneuver was performed on 11 January (DOY
011) in Orbit 40085 at 011/13:12:11. The WINDII instrument had finished
its observation of Polar Mesospheric Clouds and therefore, UARS returned to
level flight.
The Solar Stellar Pointing Platform (SSPP) was commanded (via the stored
command load) to slew to an invalid alpha angle at approximately 01:45:00 Z
on GMT Day 010 (10 January), resulting in a violation of the SSPP mask. As
a result of the commanded invalid tracking angle, the SSPP Failure
Detection and Correction (FDC), as well as Telemetry Monitor (TMON) numbers
25, 26, and 29 tripped shortly thereafter. Investigation showed that the
invalid SSPP tracking angle was generated by the Command Management System
(CMS) due to an error in the Flight Dynamics Facility (FDF) provided 3-Day
Spacecraft (S/C) Orbital Events file. The incorrect Orbital Events file
did NOT contain the required Spacecraft Yaw Maneuver (SC_YAWMAN) event. The
SSPP was returned to operation following the scheduled Yaw Around Maneuver
on 11 January 1999.
The daily UARS ephemeris load (TDRS and Spacecraft) scheduled for
transition on 12 January at 012/23:40:00 UTC did not execute due to an
error. The Ephemeris data quality indicators - NEWUFAIL for the spacecraft
and NEWTFAIL for TDRS ephemeris - indicated reject at the time of schedule
transition. The previous ephemeris continued to execute and the spacecraft
ephemeris residuals were exhausted at 013/06:02:19 UTC. Ephemeris
processing continued with potential error accumulation. A dump of the OBC
Status Buffer dump indicated the that the transition failure was due to
RWRONG YR IN EPH LD.S Additional dumps of the ephemeris data were analyzed
and the incorrect epoch year value of 1989 was confirmed. Investigation
revealed that the CMS ephemeris generation process uses the OBC Clock epoch
year as an input. The generation sequence was re-examined and a connection
was made to the operator Rlog inS file which points to the correct software
environment directory. An incorrect reference was discovered in the
directory used to generate the ephemeris load. A new load was generated
using a different directory and loaded. The load successfully transitioned
on 13 January 1999 at 013/10:35:40 UTC and no Spacecraft problems were
observed.
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 1.1 to 1.6 degrees C. Additional battery performance data
for each battery on 08 January 1999 and 15 January 1999 are provided in
Appendix D.
The clock error ranged from 4.6 to 10.4 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 = 01
% OUT-OF-LIMITS = 02
The following real-time command sheets were executed for the listed
operational element(s) during this report period (see Appendix A).
% FOT 07
% HALOE 04
% HRDI 02
% PEM 02
% SOLSTICE 01
% WINDII 01
UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.
% FOT 05
One (1) Anomaly Report remained OPEN at the end of this report period (see
Appendix E).
TRANSPONDER FREQUENCIES:
Transponder A: 99/362 - 2287.496912
Transponder B: 99/357 - 2287.499093
GROUND SYSTEM OPERATION
Two (2) 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 99/014 show the observatory data loss to be
21 hours, 50 minutes, 4.308 seconds (an increase of nine (9) minutes and
2.368 seconds since last report period). This is a 0.0341 percent data
loss which equals a 99.9659 percent data capture for the mission.
The increase of 2.368 seconds occurred over two (2) days:
7 25.440 seconds on Day 012 due to hit in data (IP) and overlap; and
7 08:37.536 seconds on Day 013 due to data hit and spacecraft anomaly.
The intermittent clock delta problem that the FOT has been experiencing for
the past two weeks was identified as being the result of the MSOCC operator
incorrectly entering 1998 into the software menu when booting up the Perkin
Elmer/AP. This incorrect year prevented the clock delta equation processor
from being able to correctly calculate a clock delta value during certain
real-time events (when the incorrect year was entered).
A hardware failure occurred last week on the UARS Test and Training
Simulator (UTTS). The FOT has not yet received an estimated time to repair
the UTTS and return it to operation.
OTHER SIGNIFICANT EVENTS
UARS SATELLITE OPERATIONS
Two Anomaly Investigation Reports (AIR-002 and AIR99-004) were issued this
report period.
The FOT continues to investigate the feasibility of a new PMON action to
change battery V/T curves based on loading to mitigate battery risks in sun
pointing safehold.
YEAR 2000 OPERABILITY SUPPORT - No change
UARS PROPULSION MODULE B/D THRUSTER LINE FILL
Planning continues for the simulator testing.
UARS RE-ENGINEERING - TELEMETRY PROCESSING - No change
MEETINGS
UARS was represented by Anisa Ahmad of NASA's power group at this month's
Battery teleconference held on Tuesday, 12 January 1999. The next meeting
will be held at 1:00 pm on 09 February. No issues are outstanding.
FUTURE SIGNIFICANT EVENTS
The next UARS Yaw Around Maneuver is scheduled for scheduled for 20
February 1999.
The next annular solar eclipse will occur on 16 February 1999 over the
Indian Ocean, Australia and the South Pacific Ocean.
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 15 January 1999
ORBIT AOS NO. SUBSYS REASON
----- --- --- ------ -------
40064 010/0416 99-010 SOLSTICE EPROM Reboot Cmds
40076 010/2334 99-011 WINDII Power OFF
40088 011/1822 99-012 SSPP FDC recovery
40104-6 012/2025 99-013 HRDI HRDI REBOOT
40110 013/0532 99-014 HRDI MUB Enabled
40111 013/0650 99-015 MACS ESAM-2 ON
40111 013/0713 99-015 MACS ESAM-2 HITRQ
40112 013/1001 99-016 CADH XMTR NOOP
40113 013/1054 99-017 MACS ESAM-2 OFF
40115 013/1401 99-018 PEM PEM CAL START
40117 013/1650 99-019 PEM PEM CAL STOP
40130 014/1409 99-021 NCC TEST GCMR PROC
40134 014/2026 99-022 HALOE Power ON
40138 015/0136 99-023 HALOE Power ON (FULL)
40139 015/0319 99-024 HALOE Power OFF (LOW)
40144 015/1147 99-025 HALOE Power ON (FULL)
40148 015/1901 99-026 OBC Clk Adj fr 0.00 to 20.6 msec/day
_______________________________________________________________
APPENDIX B
OUT-OF-LIMITS & ALERTS OCCURRENCES
Week ending 15 January 1999
MNEMONIC STATE DESCRIPTION ORBITS
--------- ----- ------------ ------
HRPTSPBIMON R-LO HRDI TELE PULSE BUS CUR MON 40059,87,46-48
NBRECBI Y-HI NBTR B Current 40146-48
The following ALERT occurrences were detected:
MNEMONIC DESCRIPTION ORBITS
--------- ------------ ------
SSFDCFAIL SSPP FDC failure 40063-88
_______________________________________________________________
APPENDIX C
CLOCK & SOLAR ARRAY RATE CORRECTIONS
Week ending 15 January 1999
CLOCK DRIFT RATE ADJUSTMENTS
ORBIT TIME CLOCK RATE CHANGE
----- ---- -----------------
40148 015/19:08 (15 Jan 99) from 00.0 to 20.6 msec/day
_______________________________________________________________
APPENDIX D
UARS BATTERY PERFORMANCE DATA
Week ending 15 January 1999
08 Jan 1998 - GMT Day 008 Beta = 11.6 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 +50.4/+22.4 -3.68/-4.62 +0.0/ +0.0 16.8 0.000 0.0
2 +84.0/0.0 +5.15/+4.51 +31.6/-14.0 25.6 1.020 21.1
3 +44.8/-5.6 +3.87/+2.92 +30.4/-14.4 25.6 1.018 20.7
15 Jan 1999 - GMT Day 015 Beta = 14.6 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 +44.8/+22.4 -3.05/-4.62 +0.0/ +0.0 16.8 0.000 0.0
2 +112.0/+11.2 +7.09/+5.15 +32.0/-15.2 23.8 1.023 23.1
3 +22.4/-22.4 +5.47/+3.87 +31.6/-16.8 23.7 1.022 23.0
V/T LEVEL CHANGES
ORB# TIME LVL FR-TO
----- -------- ----------
no changes V/T 5
APPENDIX E
UARS ANOMALY REPORTS
Week ending 15 January 1999
NEW ANOMALY REPORTS GENERATED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-003 AP 40074 010/2004 N/A No clk delta for 18 orbit
99-002 SSPP 40063 010/0235 N/A SSPP FDC FAILURE
99-001 FOT 40096 012/0646 14170 Generic Late Acquisition
99-001 FOT 40105 012/2202 14170 Generic Late Acquisition
99-004 OBC 40110 013/0532 Ephemeris rejected
ANOMALY CLOSURE INFORMATION RECEIVED
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-002 FOT 40063 010/02:35 SSPP-FDC FAIL
99-003 FOT 40074 010/20:04 NO CLOCK DELTA
99-004 FOT 40110 013/05:32 EPHEMERIS REJECT
ANOMALY INVESTIGATION REPORTS GENERATED
AIR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------- ------ ----- ---- --- -----------------
99-002 FOT 40063 010/02:35 SSPP FDC TRIP
99-004 FOT 40110 013/05:32 EPHEMERIS ERROR
OPEN ANOMALY REPORTS
AR NO. SUBSYS ORBIT TIME TTR PROBLEM/DATA LOSS
------ ------ ----- ---- --- -----------------
99-001 FOT see list Jan 98 14170 Generic Late Acq
SEVNTFW99/03