UARS Weekly Status Report

25 April 2003




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                UARS WEEKLY STATUS REPORT - 25 APR 2003

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***********
SOLSTICE
***********

Nothing received.

***********
SUSIM
***********

SUSIM successfully gathered all of its daily mid resolution, weekly
offset, and occultation scans this past week during periods of UARS
telemetry.

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ACRIM
***********

Nothing received.

***********
PEM
***********

Nothing received.

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HALOE 
***********

Nothing received.

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MLS
***********

Nothing received.

***********
HRDI
***********

Nothing received.

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WINDII
***********

Nothing received.

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MPG
***********

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.

***********
CDHF
***********

Nothing received.
                  
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FOT
***********

                           REPORTING PERIOD

This report covers 12 April 2003 (Orbit 63360, GMT Day 102) through 18
April 2003 (Orbit 63465, GMT Day 108).


                         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
       PEM           102/1158      63367     POWER ON - DAY ONLY
       WINDII        103/1238      63383     POWER ON


The  beta  angle  ranged between the angles of 23.7  degrees  to  48.9
degrees  for  this  report period.  The beta angle is  now  increasing
towards a maximum angle of 70 degrees on 26 April 2003 (DOY 116).

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 1.59 to 1.92 degrees C.  Additional
battery  performance data for each battery on 11 April  and  18  April
2003 are provided in Appendix D.

The  clock  error  ranged  from -9.9 to 9.9 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       =    02
    PEM       =    01
    WINDII    =    01



UARS Anomaly Reports initiated during this report period are listed in
Appendix E and summarized below.

    FOT  =    03

Four (4) 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


The preliminary Eclipse build, which was expected on Tuesday, was
delayed due to the status buffer issues.  Raytheon requested a new
telemetry capture file to test their functionality.  This required
bring up the UARS simulator, which did not work properly on Tuesday.
The simulator was fixed by Thursday afternoon and the data file was
sent to Denver on Friday.  The FOT is waiting to hear back from
Denver, as to whether or not the capture file allowed them to test
their new code properly.  If not then Denver will send someone out to
Goddard to work with the FOT on testing the status buffer code.  In
the meantime the preliminary build is scheduled to come out on Monday,
so that at least the WAIT code can be tested.

UARS experienced some ground system problems this weekend. On
Saturday at approximately 102/1400 GMT, the Eclipse primary
configuration stopped updating telemetry.  The workstations were
rebooted and the configurations would not restart.  At this point the
offline engineers were notified and the FOD was told to call in the
system administration support.  Once the SA arrived, he rebooted the
servers on three different occasions to no avail and finally rebooted
the CISCO switches.  The reboot of the switches solved the problem and
the configurations were restored to their nominal state.
Unfortunately, the online crew could not observe the spacecraft until
102/1921 GMT.  No data was lost however since PACOR-A has their own
realtime feed.

More network issues were experienced throughout the week, specifically
Tuesday and Friday.  All indications lead back to CISCO switch one as
the source of the problem.  Eclipse system administrators are still
investigating the problem and may order a replacement switch.

The tape drive, which is used to capture the backups of the Eclipse
system, was also found to be malfunctioning on Tuesday.  A new drive
was ordered and installed on Thursday afternoon, but this drive did
not work either.  Another new drive was ordered and will be installed
next week.


                               MEETINGS


The FOT called a meeting on Tuesday to discuss the network issues seen
over the weekend and discuss investigative actions and possible fixes.

The  FOT  attended  the weekly UARS DRB to review  the  open  DRs  and
discuss the details of the next Eclipse software delivery


                       FUTURE SIGNIFICANT EVENTS

The  next UARS Yaw slew is scheduled for 16 May 2003 (DOY 136).   This
maneuver  will  be  a  Forward to Reverse  Flight  maneuver  (Southern
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 18 April 2003


ORBIT   AOS        NO.      SUBSYS      REASON
-----   ---        ---      ------      ------
63367   102/1158   03-092   PEM         POWER ON - DAY ONLY
63383   103/1238   03-093   WINDII      POWER ON
63426   106/0911   03-094   OBC/CLK     CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
63445   107/1558   03-095   OBC/CLK     CLK ADJ FR 20.6 TO 0.0 MSEC/DAY



                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                       Week ending 18 April 2003

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 18 April 2003

                     CLOCK DRIFT RATE ADJUSTMENTS

ORBIT          TIME                   CLOCK RATE CHANGE
-----          -----                  -----------------
63426          106/0917               CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
63445          107/1604               CLK ADJ FR 20.6 TO 0.0 MSEC/DAY



                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                       Week ending 18 April 2003

     11 April 2003 - GMT Day 101 Beta = 19.4 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  -179.2/-212.8  -3.99/-4.94  +00.0/+00.0  08.3     0.000     0.0
2   +11.2/-78.4   +5.15/+3.55  +28.8/-14.4  25.1     1.020    19.5
3   +22.4/-22.4   +3.23/+2.60  +28.0/-14.4  25.1     1.010    19.0


     18 April 2003 - GMT Day 108 Beta = 48.9 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  -190.4/-224.0  -3.68/-4.94  +00.0/+00.0  08.3     0.000     0.0
2   +11.2/-145.6  +5.47/+3.55  +25.2/-15.2  25.4     1.040    20.0
3   +22.4/-44.8   +4.51/+2.92  +24.8/-15.2  25.4     1.030    19.8


     V/T LEVEL CHANGES
ORB#           AOS TIME   LVL FR-TO
-----          --------   ---------
-None this report period.



                              APPENDIX E
                         UARS ANOMALY REPORTS
                       Week ending 18 April 2003

                     NEW ANOMALY REPORTS GENERATED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
03-013    FOT       63368     102/1340  NA        Eclipse Network Issues
03-011    FOT       63427     106/1149  30832     Generic Late Acquisition
03-011    FOT       63427     106/1149  30832     Generic Late Acquisition

                 ANOMALY CLOSURE INFORMATION RECEIVED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
03-011    FOT       63308     098/1349  30832     Generic Late Acquisition

                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
------    ------    -----     ----      ---       -----------------
03-009    FOT       63069     082/1624  N/A       Invalid COP Status
03-013    FOT       63368     102/1340  NA        Eclipse Network Issues
03-011    FOT       63427     106/1149  30832     Generic Late Acquisition
03-011    FOT       63427     106/1149  30832     Generic Late Acquisition