UARS Weekly Status Report

27 December 2002




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                UARS WEEKLY STATUS REPORT - 27 Dec 2002

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

                           REPORTING PERIOD

This report covers 14 December 2002 (Orbit 61571, GMT Day 348) through
20 December 2002 (Orbit 61676, GMT Day 354).


                         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
       HALOE         348/2146      61585     POWER OFF
       SOLSTICE      354/1316      61669     DAY ONLY TO FULL TIME
       SUSIM         354/1458      61670     POWER ON


A Forward-to-Reverse Yaw Around maneuver (number 115) was successfully
executed in Orbit 61641 beginning 352/15:33:11Z and completing at
352/16:10:21Z on 18 December 2002.  All instruments were in their off
or standby mode (including HRDI and PEM).  Due to the SA position at
269 degrees, the effective night length of the spacecraft after the
maneuver was approximately 57.34 minutes.  Post maneuver analysis of
data indicate that during the Yaw Around, the end-of-night load bus
voltage was 26.24 volts and the average depths of discharge (DODs) on
Batteries 2 and 3 were approximately 20.86 and 20.16 percent
respectively.  The next (reverse-to-forward) YAW is scheduled for 27
January 2002 (DOY 027).

The  beta  angle  ranged between the angles of 14.5  degrees  to  05.2
degrees  for  this  report period.  The beta angle is  now  increasing
towards a maximum angle of 79 degrees on 08 January 2003 (DOY 008).

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 0.68 to 0.96 degrees C.  Additional
battery  performance  data for each battery  on  13  December  and  20
December 2002 are provided in Appendix D.

The  clock  error ranged from -10.1 to -10.9 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       =    03
    HALOE     =    01
    SOLSTICE  =    01
    SUSIM     =    01


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

    FOT  =    00

Two  (2) Anomaly Reports remained OPEN at the end of this report period
(see Appendix E).

                        GROUND SYSTEM OPERATION

Zero  (0) 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 successfully completed yet another yaw maneuver.  As with all
maneuvers as of late, the FOT put UARS into a higher VT charging level
for one orbit before and remain at the higher VT level for one day
after the yaw to allow the batteries to recover.

The FOT continued testing the OBC image from the OBC crash with the
simulator this week.  Nothing out of the ordinary has been seen yet to
date.

                               MEETINGS

-None this report period.

                       FUTURE SIGNIFICANT EVENTS

The  next  UARS Yaw slew is scheduled for 27 January 2003  (DOY  027).
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 20 December 2002


ORBIT   AOS        NO.      SUBSYS      REASON
-----   ---        ---      ------      ------
61585   348/2146   02-489   HALOE       POWER OFF
61587   349/0116   02-490   OBC/CLK     CLK ADJ FR -20.6 TO 0.0 MSEC/DAY
61640   352/1405   02-493   MACS        YAW MANEUVER FWD TO REV
61656   353/1556   02-493   MPS         BACK TO VT LEVEL-5
61659   353/2115   02-494   MPS         BATSOC RESET
61669   354/1316   02-496   SOLSTICE    DAY ONLY TO FULL TIME
61670   354/1458   02-497   SUSIM       POWER ON - START
61671   354/1554   02-497   SUSIM       POWER ON - CONTINUE
61673   354/1931   02-497   SUSIM       POWER ON - COMPLETE


                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                     Week ending 20 December 2002

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 December 2002

                     CLOCK DRIFT RATE ADJUSTMENTS

ORBIT          TIME                   CLOCK RATE CHANGE
-----          -----                  -----------------
61587          349/0116               CLK ADJ FR -20.6 TO 0.0 MSEC/DAY



                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                     Week ending 20 December 2002

     13 December 2002 - GMT Day 347 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  -156.8/-179.2 -3.05/-4.31  +00.0/+00.0  08.3      0.000     0.0
2   +44.8/-22.4  +6.43/+5.14  +29.6/-14.8  24.2      1.030    22.0
3   +22.4/-50.4  +5.14/+3.87  +28.8/-15.2  24.2      1.020    21.7


     20 December 2002 - GMT Day 354 Beta = 05.2 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  -156.8/-179.2 -3.68/-4.94  +00.0/+00.0  08.3      0.000     0.0
2   +16.8/-33.6  +5.14/+4.50  +29.6/-13.6  25.0      1.030    19.7
3   +28.0/-33.6  +3.87/+2.91  +28.4/-13.6  25.0      1.020    19.2


     V/T LEVEL CHANGES
ORB#           AOS TIME   LVL FR-TO
-----          --------   ---------
61640          352/1405   L5 -> L6
61656          353/1556   L6 -> L5



                              APPENDIX E
                         UARS ANOMALY REPORTS
                     Week ending 20 December 2002

                     NEW ANOMALY REPORTS GENERATED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
-None this report period.

                 ANOMALY CLOSURE INFORMATION RECEIVED
AR NO.    SUBSYS    ORBIT     TIME      CDS       PROBLEM/DATA LOSS
------    ------    -----     ----      ---       -----------------
02-061    FOT       61512     344/0124  31907     33 Second 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
------    ------    -----     ----      ---       -----------------
02-058    FOT       61113     317/1341  N/A       NEG ACQ / UFLTR ERROR
02-060    FOT       61421     338/0057  N/A       PSU Cmd Clock Timeout