UARS Weekly Status Report

16 May 2003




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                UARS WEEKLY STATUS REPORT - 16 May 2003

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

SOLSTICE continues to perform nominally, taking solar data on all
available orbital tracking periods.

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

SUSIM was powered off on May 14 for the yaw-around.  Otherwise, it
successfully gathered all of its daily mid resolution, weekly offset,
and O2 occultation scans this past week during periods of UARS
telemetry or tape recording.

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

Nothing received.

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

     The PEM web site has moved.  It has a new URL.  Access the PEM web site
using http://wwwpem.space.swri.edu.  The PEM data from the GUVI conjunction
periods has moved to http://wwwpem.space.swri.edu/guvi-pem.html.

     Level 2 PEM HEPSA data files are being reprocessed for submission to the 
DAAC.  This data has been designated as version 2; however, there is no format
difference from the version 1 data format.  Version 2 HEPSA data is being 
generated because it was discovered that there exists processing errors within
some of the HEPSA version 1 data files.  Thus, if you are using any HEPSA
version 1 data files from the DAAC, please replace them with the version 2
data files.  Currently, HEPSA data between 1991274 and 2001365 has been 
reprocessed and archived at the GSFC DAAC.  SwRI is working on reprocessing
data PEM for 2002.

     PEM continues to work with the GUVI team on the diagnosis of data from
the first conjunction period.  Analysis of the two conjunction passes showed
that the aurora as detected by GUVI was at higher latitude than UARS.  
GUVI images from other times from the first conjunction period show spatial
regions that both GUVI and PEM sampled when aurora was present.  Separation
is several minutes to 10's of minutes when both instruments saw aurora. 
PEM has seen no aurora during the second conjunction period.  Due to a 
spacecraft anomaly, no PEM data was collected during the third conjunction 
period.

     PEM continues to receive NMC data files from NOAA.  No problems have
been encountered.  NOAA has changed the binary structure of the NMC data and
PEM is now receiving two data streams, one in the original VAX format and the
other from their new binary format.

*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.

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

HALOE continues to perform successfully during scheduled operational 
periods.  All engineering parameters are within nominal limits and the 
science data products are reasonable.  Science data processing continues 
but is occasional affected by "clipped" events that result in missed events 
or require special processing to recover the events.  New software is being 
added to evaluate each 24 hour file to check for problems in the file, such 
as "time jumps" in the data, so that appropriate processing can be used and 
responsible level 0  individuals at UARS can be alerted.

The AIX IBM computer system that generates the plots and netcdf files for 
the HALOE web site has failed and we are in the process of getting it back 
in operation.  Since it is an old system we are also investigating 
alternate solutions.

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

Nothing received.

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

Nothing received.

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

Nothing received.

***********
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.
                  
***********
FOT
***********

                           REPORTING PERIOD

This  report covers 03 May 2003 (Orbit 63676, GMT Day 123) through  09
May 2003 (Orbit 62781, GMT Day 129).


                         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         123/1158      63684     POWER ON
       WINDII        128/1004      63757     POWER OFF


The  beta  angle  ranged between the angles of 49.9  degrees  to  28.0
degrees  for  this  report period.  The beta angle is  now  decreasing
towards a minimum angle of 0 degrees on 16 May 2003 (DOY 136).

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 1.27 to 1.28 degrees C.  Additional
battery  performance data for each battery on 02 May and 09  May  2003
are provided in Appendix D.

The  clock  error  ranged from -11.0 to 10.0 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
    HALOE     =    01
    WINDII    =    01



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

    FOT  =    06

Six  (6) Anomaly Reports remained OPEN at the end of this report period
(see Appendix E).


                        GROUND SYSTEM OPERATION

Six  (6)  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 worked with the Raytheon development team to try
resolve the problems seen in the preliminary build.  The FOT believes
that all of the wait statement issues have been resolved, but will
await testing of the official build to confirm that this code works
properly.  The status buffer display has been modified as well, with
the only outstanding issue being the Eclipse time field.  The
development team has a handle on this problem and feels that it will
be resolved soon.  This functionality will also be tested when the
official build arrives.

The FOT also spoke with Anisa Ahmad of the NASA Power Branch,
regarding the duration of the VT-6 mode following the next UARS yaw
maneuver on 16 May 2003.  This issue was raised due to the relatively
sluggish recovery after the last yaw maneuver on 06 April 2003.  Past
analysis of the power data has shown the summer yaw maneuvers have a
longer post-maneuver recovery time.  It was recommended, due to this
fact, that after the upcoming yaw the batteries should be kept in VT-6
until telemetry indicates it should be removed, but no longer than 3
days.  This recommendation will be implemented pending NASA Mission
Directors approval.


                               MEETINGS


The FOT attended the UARS monthly on 06 May 2003, to report spacecraft
and operations status for the month of April.

The  FOT  also attended the weekly UARS DRB on 06 May 2003, 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 09 May 2003


ORBIT   AOS        NO.      SUBSYS      REASON
-----   ---        ---      ------      ------
63684   123/1158   03-105   HALOE       POWER ON
63709   125/0600   03-106   OBC/CLK     CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
63728   126/1151   03-107   OBC/CLK     CLK ADJ FR 20.6 TO 0.0 MSEC/DAY
63757   128/1004   03-108   WINDII      POWER OFF (S/C LOW PWR)



                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                        Week ending 09 May 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 09 May 2003

                     CLOCK DRIFT RATE ADJUSTMENTS

ORBIT          TIME                   CLOCK RATE CHANGE
-----          -----                  -----------------
63709          125/0602               CLK ADJ FR 0.0 TO 20.6 MSEC/DAY
63728          126/1158               CLK ADJ FR 20.6 TO 0.0 MSEC/DAY


                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                        Week ending 09 May 2003

     02 May 2003 - GMT Day 122 Beta = 55.8 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  -235.2/-263.2  -3.68/-4.94  +00.0/+00.0  08.3     0.000     0.0
2   +05.6/-67.2   +3.87/+2.92  +23.2/-15.2  25.8     1.030    18.8
3   +16.8/-44.8   +2.92/+1.97  +22.4/-14.4  25.6     1.020    18.4

     09 May 2003 - GMT Day 129 Beta = 28.0 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  -700.0/-700.0  -3.05/-4.62  +00.0/+00.0  07.7     0.000     0.0
2   +11.2/-78.4   +5.15/+3.87  +28.4/-15.2  23.8     1.040    20.2
3   +22.4/-72.8   +3.87/+2.60  +27.2/-15.2  23.8     1.030    19.9

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

                              APPENDIX E
                         UARS ANOMALY REPORTS
                        Week ending 09 May 2003

                     NEW ANOMALY REPORTS GENERATED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
03-019    FOT       63727     126/1008  N/A       SEC Eclipse (PBK Problem)
03-020    FOT       63732     126/1334  32470     DROPOUTS ON I CHANNEL
03-018    FOT       63732     126/1757  30832     Generic Late Acquisition
03-021    FOT       63733     126/1943  32743     Late Acq 15 min recoverable
03-022    FOT       63742     127/0929  N/A       PBK PROBLEM(REF 03-019)
03-023    FOT       63773     129/1105  32761     MULTIPLE DATA DROPOUTS

                 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
------    ------    -----     ----      ---       -----------------
03-018    FOT       See List  May 03    30832     Generic Late Acquisition
03-019    FOT       63727     126/1008  N/A       SEC Eclipse (PBK Problem)
03-020    FOT       63732     126/1334  32470     DROPOUTS ON I CHANNEL
03-021    FOT       63733     126/1943  32743     Late Acq 15 min recoverable
03-022    FOT       63742     127/0929  N/A       PBK PROBLEM(REF 03-019)
03-023    FOT       63773     129/1105  32761     MULTIPLE DATA DROPOUTS