UARS Weekly Status Report

9 April 2004




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                UARS WEEKLY STATUS REPORT - 09 April 2004

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

This week, SOLSTICE continued to operate in good health gathering solar 
data on all available orbital tracking periods. On average, we received 
68% of each day's data amounting to about 500 minutes of solar 
observing time per day.

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

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

***********
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 1996039.

     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 
***********

Nothing received.

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

Nothing received.

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

Nothing received.

***********
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 27 March 2004 (Orbit 68623, GMT Day 087) through 
02 April 2004 (Orbit 68728, GMT Day 093).


                         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           087/2001      68635     POWER OFF
       SUSIM         087/2112      68636     POWER OFF
       SOLSTICE      087/2219      68637     TO DAY-ONLY OPS
       SOLSTICE      091/1354      68692     DAY-ONLY TO FULL-TIME
       SUSIM         091/1717      68694     POWER ON
       PEM           093/1348      68722     POWER ON ZEPS/HEPS DAY-only


A Reverse-to-Forward Yaw Around maneuver (number 128) was successfully
executed in Orbit 68662 beginning 089/14:51:09Z and completing at
089/15:28:19Z on 29 March 2004.  All instruments were in their off or
standby mode (except for SOLSTICE in day-only).  Due to the SA
position at 269 degrees, the effective night length of the spacecraft
after the maneuver was approximately 55.43 minutes.  Post maneuver
analysis of data indicate that during the Yaw Around, the end-of-night
load bus voltage was 26.08 volts and the average depths of discharge
(DODs) on Batteries 2 and 3 were approximately 20.74 and 20.27 percent
respectively.  The next (forward-to-reverse) YAW is scheduled for 07
May 2004 (DOY 128).

The beta angle ranged between the angles of 11.5 degrees to 18.4
degrees for this report period.  The beta angle is now increasing
towards a maximum angle of 68 degrees on 17 April 2004 (DOY 108).

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 0.95 to 1.27 degrees C.  Additional
battery performance data for each battery on 26 March and 02 April
2004 are provided in Appendix D.

The clock error ranged from 10.2 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       =    04
    PEM       =    02
    SUSIM     =    02
    SOLSTICE  =    02


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

    FOT  =    01

Two (2) Anomaly Reports 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


The FOT transitioned to the 3-TDRS mode of operations on 17 March
2004.  The FOT is now taking 35-38 events per day (up from 26-28 per
day under 2-TDRS operations) and collecting data for an additional 18-
20% more of each orbit.  So far no problems have been found with this
mode and all subsystems remain nominal.


                               MEETINGS


The FOT attended a meeting with the HRDI team on 02 April 2004 in
order to follow up on the attitude error issue.  Data sets are still
be collected and analyzed.  The FOT will meet with the HRDI team again
in two weeks to discuss their findings.

                                   
                       FUTURE SIGNIFICANT EVENTS

The next UARS Yaw slew is scheduled for 07 May 2004 (DOY 128).  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 02 April 2004

ORBIT   AOS        NO.      SUBSYS      REASON
-----   ---        ---      ------      ------
68626   087/0542   04-093   OBC/CLK     CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
68635   087/2001   04-094   PEM         POWER OFF
68636   087/2112   04-095   SUSIM       POWER OFF
68637   087/2219   04-096   SOLSTICE    TO DAY-ONLY OPS
68647   088/1456   04-097   MACS        YAW VT-6
68662   089/1416   04-097   MACS        YAW
68682   090/2155   04-098   OBC/CLK     CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
68692   091/1354   04-099   SOLSTICE    DAY-ONLY TO FULL-TIME
68693   091/1616   04-097   MACS        YAW VT-5
68694   091/1717   04-100   SUSIM       POWER ON (PART 1)
68706   092/1309   04-100   SUSIM       POWER ON (PART 2)
68700   092/0332   04-101   OBC/CLK     CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
68722   093/1348   04-102   PEM         POWER ON ZEPS/HEPS DAY-ONLY


                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                       Week ending 02 April 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 02 April 2004

                     CLOCK DRIFT RATE ADJUSTMENTS

ORBIT          TIME                   CLOCK RATE CHANGE
-----          -----                  -----------------
68626          087/0546               CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
68682          090/2155               CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
68700          092/0334               CLK ADJ FR -20.6 TO 0.0 MSEC/DAY


                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                       Week ending 02 April 2004


     26 March 2004 - GMT Day 086 Beta = 12.1 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/-4.63  +00.0/+00.0  07.0     0.00      0.0
2     +11.2/-134.4 +5.79/+3.87  +28.0/-14.4  23.7     1.02     19.8
3     +22.4/-089.6 +5.14/+2.60  +27.2/-14.4  23.5     1.02     19.5

     02 April 2004 - GMT Day 093 Beta = 18.4 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    -700.0/-700.0 -3.68/-4.94  +00.0/+00.0  07.0     0.00      0.0
2     +11.2/-22.4  +4.50/+3.23  +28.4/-12.8  26.1     1.03     19.3
3     +22.4/-33.6  +3.23/+2.28  +27.2/-12.4  26.1     1.01     19.1


     V/T LEVEL CHANGES                                           
ORB#           AOS TIME   LVL FR-TO
-----          --------   ---------
68647          088/1456   LV5 -> LV6
68693          091/1616   LV6 -> LV5


                              APPENDIX E
                         UARS ANOMALY REPORTS
                       Week ending 02 April 2004

                     NEW ANOMALY REPORTS GENERATED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
04-016    FOT       68708     092/1613  35490     Drop out due to HW @ WSGT

                 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
------    ------    -----     ----      ---       -----------------
04-014    FOT       See List  Mar 04    30832     Generic Late Acquisition
04-016    FOT       68708     092/1613  35490     Drop out due to HW @ WSGT