UARS Weekly Status Report

28 May 2004




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                UARS WEEKLY STATUS REPORT - 28 MAY 2004

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

Nothing received.

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

SUSIM successfully gathered its daily mid (1.1 nm) resolution, MgII,
occultation, solar pointing offset, and high resolution continuous
monitoring scans for periods of UARS real-time telemetry or onboard
tape recording.

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

     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 2003365 has been 
reprocessed and archived at the GSFC DAAC.  

     Level 2 PEM MEPS data file documentation is complete and submitted to 
the DAAC.  MEPS data files are version 1.  Processed MEPS data files at the 
DAAC archive are between 1991274 and 1999365.

     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.

     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

*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 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.

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

Nothing received.
                  
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FOT
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                           REPORTING PERIOD

This  report covers 15 May 2004 (Orbit 69360, GMT Day 136) through  
21 May 2004 (Orbit 69465, GMT Day 142).


                         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
       HRDI          137/0324      69377     FULLTIME OPS TO LOW POWER


The beta angle ranged between the angles of 26.7 degrees to 36.2
degrees for this report period.  The beta angle is now increasing
towards a maximum angle of 36 degrees on 22 May 2004 (DOY 143).

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 0.97 to 1.27 degrees C.  Additional
battery performance data for each battery on 14 May and 21 May 2004
are provided in Appendix D.

The clock error ranged from 09.9 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       =    03
    HRDI      =    01



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

    FOT  =    01

One (1) Anomaly Report remained OPEN at the end of this report period
(see Appendix E).


                        GROUND SYSTEM OPERATION

One (1) operational support problem 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


On Friday, 14 May 2004 the FOT observed the differential voltage
rising to approximately 200 mV and it maintaining this value for the
duration of the weekend.  Typically this value runs around 30-60 mV
and occasionally gets into the hundreds but usually doesn't stay there
for long.  The NASA Power Branch representative was informed, and a
decision was made to go to our more aggressive charge rate (VT-6).
This was done on Monday, May 17 2004 and after only two orbits the
differential voltage came back down to nominal levels.  The VT-6 level
was maintained throughout the week and won't be changed back to VT-5
until next week (most likely following the HRDI turn-on).  The power
availability has always dropped during the summer months, but this
seems indicative of some battery aging effects as well.  The FOT will
continue to monitor this closely.


                               MEETINGS


-None this report period.

                                   
                       FUTURE SIGNIFICANT EVENTS

The next UARS Yaw slew is scheduled for 06 June 2004 (DOY 158).  This
maneuver will be a Reverse to Forward 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 21 May 2004

ORBIT   AOS        NO.      SUBSYS      REASON
-----   ---        ---      ------      ------
69377   137/0324   04-144   HRDI        FULL-TIME OPS TO LOW POWER
69399   138/1417   04-145   MPS         FROM VT5 TO VT6
69430   140/1539   04-146   OBC         MEMORY MONITOR
69448   141/2027   04-147   OBC/CLK     CLK ADJ FR 0.0 TO 20.6 MSEC/DAY


                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                        Week ending 21 May 2004

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 May 2004

                     CLOCK DRIFT RATE ADJUSTMENTS

ORBIT          TIME                   CLOCK RATE CHANGE
-----          -----                  -----------------
69448          141/2027               CLK ADJ FR 0.0 TO -20.6 MSEC/DAY



                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                        Week ending 21 May 2004


     14 May 2004 - GMT Day 135 Beta = 24.5 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/-4.31   +00.0/+00.0 07.0     0.00      0.0
2     +11.2/-201.6 +5.79/+4.50   +28.0/-14.0 24.8     1.03     20.4
3     +11.2/-134.4 +4.50/+3.87   +27.2/-14.4 24.8     1.02     20.2

     21 May 2004 - GMT Day 142 Beta = 36.2 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 -2.42/-3.68  +00.0/+00.0  07.0     0.00      0.0
2     +11.2/-33.6  +6.11/+5.14  +26.4/-14.4  26.6     1.03     20.0
3     +33.6/-44.8  +5.14/+3.87  +25.6/-14.4  26.4     1.03     19.6


     V/T LEVEL CHANGES
ORB#           AOS TIME   LVL FR-TO
-----          --------   ---------
69399          138/1417   LV5 -> LV6


                              APPENDIX E
                         UARS ANOMALY REPORTS
                        Week ending 21 May 2004

                     NEW ANOMALY REPORTS GENERATED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
04-024    FOT       69394     138/0617  30832     Generic Late Acquisition

                 ANOMALY CLOSURE INFORMATION RECEIVED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
04-025    FOT       69308     132/1357  35842     Data Dropout: data loss
04-026    FOT       69339     134/1458  35860     Data Dropouts
04-027    FOT       69344     134/2304  35864     Data Dropouts

                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
------    ------    -----     ----      ---       -----------------
04-024    FOT       See List  May 04    30832     Generic Late Acquisition