UARS Weekly Status Report

27 August 2004




********************************************************************

                UARS WEEKLY STATUS REPORT - 27 Aug 2004

********************************************************************

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

SOLSTICE resumed normal operations this week after operating only 
during daylight in support of the yaw maneuever. Otherwise, SOLSTICE 
continued to operate in good health gathering solar data on all 
available orbital tracking periods. On average, we received 54% of each 
day's data amounting to about 358 minutes of solar observing time per 
day.

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

SUSIM was turned on after the yaw-around on August 20.  Since then, the
experiment successfully gathered daily mid (1.1 nm) resolution, MgII,
occultation, solar pointing offset, and continuous monitoring scans
for periods of UARS real-time telemetry or onboard tape recording.

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

     HEPSA data files are version 2.  Currently, HEPSA data between 1991274 
and 2004079 has been reprocessed and archived at the GSFC DAAC.  Currently, 
HEPSA data between 2004080 and 2004089 has been processed waiting for
archival at the GSFC DAAC.  

     MEPS data files are version 1.  Processed MEPS data files at the 
DAAC archive are between 1991274 and 2004069.  Currently, MEPS data between 
2004070 and 2004079 has been processed waiting for archival at the GSFC DAAC.  

     PEM continues to receive NMC data files from NOAA.  No problems have
been encountered.

     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

     Requests have been received for storm spectral data.  Overview plots were 
produced and these plots may be found on the web at
http://climatology.space.swri.edu/UARS_images_postedJune2004.html
for the storms of October 29 of 1991, November 8-9 of 1991, April 6-7 of 2000, 
March 31 - April 1 of 2001, April 11-12 of 2001, November 6-7 of 2001, and 
November 11-12 of 2001.

*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 
***********

Nothing received.

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

Nothing received.

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

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 14 August 2004 (Orbit 70729, GMT Day 227)  through
21 August 2004 (Orbit 70834, GMT Day 233).


                         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           228/1945      70756     POWER OFF
       SOLSTICE      228/2208      70757     FROM FULL TO DAY ONLY
       SUSIM         228/2320      70758     POWER OFF


A Reverse-to-Forward Yaw Around maneuver (number 132) was successfully
executed in Orbit 70798 beginning 231/ 16:48:26Z and completing at
231/ 17:25:36Z on 18 August 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 55.71 minutes.  Post maneuver
analysis of data indicate that during the Yaw Around, the end-of-night
load bus voltage was 25.76 volts and the average depths of discharge
(DODs) on Batteries 2 and 3 were approximately 20.74 and 20.16 percent
respectively.  The next (forward-to-reverse) YAW is scheduled for 25
September 2004 (DOY 269).

The beta angle ranged between the angles of 14.9 degrees to 07.5
degrees for this report period.  The beta angle is now increasing
towards a maximum angle of 63 degrees on 06 September 2004 (DOY 250).

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 0.96 degrees C.  Additional
battery performance data for each battery on 13 August and 20 August
2004 are provided in Appendix D.

The clock error ranged from 10.6 to -09.9 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       =    05
    PEM       =    01
    SOLSTICE  =    01
    SUSIM     =    01


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

    FOT       =    03

Three (3) Anomaly Report 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


On 10 August 2004, during the 223/0121 Z event, VT-6 was commanded due
to the differential voltage being greater than 180 mV for three
consecutive orbits.  The differential voltage returned to nominal
values after two orbits subsequent to the change.  The spacecraft
remains in VT-6 and will be monitored closely to determine when to go
back to VT-5.

The new CMS code to allow for SMA events continued to undergo testing
this week.  Problems receiving products from FDF, transferring the
schedule from UPS to CMS, and system drive issues hindered progress.
While the FDF product and system drive issues have been resolved, the
transfer issue is still under investigation.

                               MEETINGS


-None this report period


                                   
                       FUTURE SIGNIFICANT EVENTS

The next UARS Yaw slew is scheduled for 25 September 2004 (DOY 269).
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 20 August 2004

ORBIT   AOS        NO.      SUBSYS      REASON
-----   ---        ---      ------      ------
70731   227/0329   04-232   OBC/CLK     CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
70750   228/0951   04-233   OBC/CLK     CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
70756   228/1945   04-234   PEM         POWER OFF
70757   228/2208   04-235   SOLSTICE    SOL FROM FULL TO DAY ONLY
70758   228/2320   04-236   SUSIM       POWER OFF
70798   231/1515   04-237   ACS         YAW MANEUVER
70806   232/0400   04-238   OBC/CLK     CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
70826   233/1056   04-239   OBC/CLK     CLK ADJ FR -20.6 TO 0.0 MSEC/DAY


                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 20 August 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 20 August 2004

                     CLOCK DRIFT RATE ADJUSTMENTS

ORBIT          TIME                   CLOCK RATE CHANGE
-----          -----                  -----------------
70731          227/0332               CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
70750          228/0956               CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
70806          232/0406               CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
70826          233/1056               CLK ADJ FR -20.6 TO 0.0 MSEC/DAY


                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                      Week ending 20 August 2004

     13 August 2004 - GMT Day 226 Beta = 16.5 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/-3.68  +00.0/+00.0  07.0     0.00      0.0
2     -00.0/-22.4  +5.79/+5.47  +24.8/-12.0  26.7     1.02     20.5
3     +22.4/-00.0  +4.83/+4.19  +24.0/-12.0  26.7     1.02     20.0

     20 August 2004 - GMT Day 233 Beta = 07.5 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/-4.62  +00.0/+00.0  07.0     0.00      0.0
2     +11.2/-044.8 +5.15/+4.19  +27.2/-12.0  26.4     1.04     18.8
3     +00.0/-112.0 +3.87/+2.92  +25.6/-12.0  26.4     1.05     18.2

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


                              APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 20 August 2004

                     NEW ANOMALY REPORTS GENERATED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
04-057    FOT       70751     228/1124  36677     Drop out on the Return
04-050    FOT       70755     228/1804  30832     Generic Late Acquisition
04-058    FOT       70774     230/0059  36694     7:01 Data loss:
                                                  weather@WSGT

                 ANOMALY CLOSURE INFORMATION RECEIVED
AR NO.    SUBSYS    ORBIT     TIME      CDS    PROBLEM/DATA LOSS
------    ------    -----     ----      ---    -----------------
04-053    FOT       70674     223/0845  36597  No Acquisition GDIS Prob at WS
04-054    FOT       70708     225/1549  36643  Bad Weather conditions @ Guam
04-055    FOT       70711     224/2037  36648  Data Dropout

                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
------    ------    -----     ----      ---       -----------------
04-050    FOT       See List  August 04 30832     Generic Late Acquisition
04-057    FOT       70751     228/1124  36677     Drop out on the Return
04-058    FOT       70774     230/0059  36694     7:01 Data loss:
                                                  weather@WSGT