UARS Weekly Status Report

08 August 2003




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                UARS WEEKLY STATUS REPORT - 08 August 2003

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

SOLSTICE continues to perform nominally, taking solar data on all
available orbital tracking periods. This week we received about 60% of
each day's data amounting to about 500 minutes of solar observing time
per day.

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

SUSIM successfully gathered all of its daily mid resolution, weekly
offset, and O2 occultation scans during periods of UARS telemetry or
periods of onboard tape recording.

A special high (0.15 nm) resolution scan for 115-200 nm is planned
for early on Wednesday, August 13 to roughly coincide with the
launch (about 7 hours earlier) of the U. Colorado EUV rocket.  We do
this on the next day to avoid the uncertain solar open-loop pointing
that is scheduled for Tuesdays.

***********
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 2002119 has been 
reprocessed and archived at the GSFC DAAC.  HEPSA data files from 2002120
through 2002129 are processed and awaiting archiving at the DAAC.

     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.

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

Nothing received.

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

Nothing received.

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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 26 July 2003 (Orbit 64939, GMT Day 207) through  01
August 2003 (Orbit 65043, GMT Day 213).


                         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
       SOLSTICE      209/1404      64977     DAY-ONLY TO FULLTIME OPS
       SUSIM         210/1542      64994     POWER ON (PART 1)
       HALOE         212/1356      65022     POWER ON (WARMUP)



A Forward-to-Reverse Yaw Around maneuver (number 121) was successfully
executed in Orbit 64949 beginning 207/16:27:01Z and completing at
207/17:04:11Z on 26 July 2003.  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 57.24 minutes.  Post maneuver
analysis of data indicate that during the Yaw Around, the end-of-night
load bus voltage was 25.20 volts and the average depths of discharge
(DODs) on Batteries 2 and 3 were approximately 22.10 and 21.90 percent
respectively.  The next (reverse-to-forward) YAW is scheduled for 27
August 2003 (DOY 239).

The  beta  angle  ranged between the angles of 02.2  degrees  to  22.5
degrees  for  this  report period.  The beta angle is  now  increasing
towards a maximum angle of 42 degrees on 11 August 2003 (DOY 223).

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 1.28to 1.61 degrees C.  Additional
battery  performance data for each battery on 25 July  and  01  August
2003 are provided in Appendix D.

The  clock  error  ranged from -10.2 to 09.6 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
    SOLSTICE  =    01
    SUSIM     =    01
    HALOE     =    02



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 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 FOT reviewed the data from the yaw on 26 July 2003 with the NASA
Power Branch representative Anisa Ahmad.  It was noticed that the
differential voltage on both batteries was increasing several orbits
prior to the yaw.  In order to help minimize this it was suggested
that the batteries be put into VT-6 a half or full day before the yaw
event.  This suggestion will be brought up at the monthly status
review on 5 August 2003 and any implementation will require approval
from the Mission Director.


                               MEETINGS


-None this report period



                       FUTURE SIGNIFICANT EVENTS

The  next  UARS  Yaw slew is scheduled for 27 August 2003  (DOY  239).
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 01 August 2003

ORBIT   AOS        NO.      SUBSYS      REASON
-----   ---        ---      ------      ------
64948   207/1456   03-195   MACS        YAW - FWD TO REV
64948   207/1535   03-195   MACS        YAW - FWD TO REV
64949   207/1702   03-195   MACS        YAW - FWD TO REV
64967   208/2102   03-196   OBC         CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
64977   209/1404   03-197   SOLSTICE    DAY-ONLY TO FULLTIME OPS
64978   209/1504   03-195   MPS         VT LEVEL 5
64981   209/1915   03-195   MPS         BATSOC
64985   210/0202   03-198   OBC         CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
64994   210/1542   03-199   SUSIM       POWER ON (PART 1)
65006   211/1134   03-199   SUSIM       POWER ON (COMPLETE)
65022   212/1356   03-200   HALOE       POWER ON (WARMUP)
65025   212/1724   03-201   HALOE       POWER ON (COMPLETE)


                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 01 August 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 01 August 2003

                     CLOCK DRIFT RATE ADJUSTMENTS

ORBIT          TIME                   CLOCK RATE CHANGE
-----          -----                  -----------------
64967          208/2102               CLK ADJ FR 0.0 TO -20.6 MSEC/DAY
64985          210/0205               CLK ADJ FR -20.6 TO 0.0 MSEC/DAY



                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                      Week ending 01 August 2003

     25 July 2003 - GMT Day 206 Beta = 06.3 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  07.2     0.000     0.0
2    +11.2/-134.4 +4.83/+3.55  +27.2/-12.8  24.5     1.000    19.7
3    +22.4/-44.8  +3.55/+2.60  +26.4/-12.8  24.5     1.000    19.2


     01 August 2003 - GMT Day 213 Beta = 22.5 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/       07.2     0.000     0.0
2    +00.0/-123.2 +6.44/+4.83  +28.8/-15.2  24.3     1.030    20.9
3    +22.4/-50.4  +5.15/+3.87  +28.0/-15.2  24.2     1.020    20.6

     V/T LEVEL CHANGES
ORB#           AOS TIME   LVL FR-TO
-----          --------   ---------
64948          207/1456   LV5 -> LV6
64978          209/1404   LV6 -> LV5


                              APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 01 August 2003

                     NEW ANOMALY REPORTS GENERATED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
03-037    FOT       65040     213/1722  30832     Generic Late Acquisition

                 ANOMALY CLOSURE INFORMATION RECEIVED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
03-031    FOT       See List  July 03   30832     Generic Late Acquisition
03-035    FOT       64889     203/1726  N/A       ATC HALT
03-036    FOT       64935     206/1831  N/A       Lost Lock - White S. Maint.

                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
------    ------    -----     ----      ---       -----------------
03-037    FOT       See List  August 03 30832     Generic Late Acquisition