UARS Weekly Status Report

30 March 2001




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                UARS WEEKLY STATUS REPORT - 30 Mar 2001

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

SOLSTICE continues to operate normally, collecting solar data on all 
available orbital tracking periods and stellar calibration observations, 
whenever possible. During this time of TDRSS only operations, SOLSTICE
is collecting sufficient data to fulfill our science processing requirements.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

HRDI continues to function normally, making wind measurements during
the sunlit parts of orbits nearly every day, and measuring nighttime winds
when power is available.

***********
WINDII
***********

Nothing received.

***********
MPG
***********

During this week a problem was encountered with the UARS
Command Management System.  A workaround procedure has 
been used to update instrument Daily Activity 
Plans and microloads on the Command Management System 
data base.

Instrument operations schedule is now complete
to 19 April 2001.

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

Nothing received
                  
***********
FOT
***********
 
                           REPORTING PERIOD

This report covers 17 March 2001 (Orbit 52005, GMT Day 076) through 23 March 
2001 (Orbit 52110, GMT Day 082).

                         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          
 ACRIM        076/0018     52005     Power ON
 SUSIM        076/0342     52008     Power ON (Start)
 PEM          076/1257     52013     Power ON - Day Only
 SUSIM        076/1449     52015     Power ON (Continuation)
 SUSIM        076/1539     52015     Power ON (Completion)
 SUSIM        077/2113     52034     Motor Commands
 HALOE        078/0020     52050     Power ON PART 1
 HALOE        079/1227     52058     Power ON, complete     



The beta angle ranged between the angles of 05.6 degrees to 28.0 degrees for 
this report period.  The beta angle is now decreasing towards a minimum angle 
of 52 degrees on 02 April 2001 (DOY 074).

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 23.8 V end-of-night (EON) load bus voltage.  Battery 
temperatures are stable with a temperature delta between Battery 2 and Battery 
3 of 1.3 and 1.6 degrees C.  Additional battery performance data for each 
battery on 16 March 2001 and 23 March 2001 are provided in Appendix D.


The clock error ranged from Ð0.7 to 8.0 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            =  10
¥     ACRIM          =  01
¥     SUSIM          =  04
¥     PEM            =  01
¥     HALOE          =  02

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

¥     FOT            =  02

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

TRANSPONDER FREQUENCIES:
· Transponder A:  00/316  - 2287.496493
· Transponder B:  02/026  - 2287. 49920005


                      GROUND SYSTEM OPERATION


Two (2) operational support problems occurred this period.  Anomaly Reports are 
included in Appendix E.

The data loss calculations supplied by Data Capture Facility (DCF) from mission 
start through UTC Day 01/067 show the observatory data loss to be 300 hours, 1 
minute, 12.760 seconds. This shows an overall increase of 43.296 seconds since 
the last report period. This is a 0.39 percent data loss, which equals a 99.61 
percent data capture for the mission.

The increase of 43.296 seconds occurred over two (3) days:

á     14.304 seconds on Day 071 due to No Data Overlap
á     14.128 seconds on Day 074 due to No Data Overlap
á     14.864 seconds on Day 074 due to No Data Overlap


                     OTHER SIGNIFICANT EVENTS


                     UARS SATELLITE OPERATIONS

UARS is using both the Fine Sun Sensor (FSS) and the Three Axis Magnetometer 
(TAM) as inputs to UFLTR this week.  The FOT is pleased with their performance, 
but continues to make adjustments to the TAM alignment to improve its 
performance and UARSÕ attitude.

The FOT awaits the completion of the FSW patch that will improve the magnetic 
field model from a 5th order to 7th order solution.  The patch is currently begin 
tested on the UARS Testing and Training Simulator (UTTS).  Testing should be 
completed in the next few weeks.

                              MEETINGS

The FOT attended a UARS Attitude Meeting on Monday, March 19, 2001
The FOT attended the UARS SERB Meeting on Wednesday, March 21, 2001.


                      FUTURE SIGNIFICANT EVENTS


The next UARS Yaw slew is scheduled for 19 April 2001 (DOY 109).  This maneuver 
will be a Reverse to Forward Flight maneuver (Southern Hemisphere viewing).


Attachments:  Appendix A,  Real-time Commands 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 23 March 2001

ORBIT     AOS          NO.        SUBSYS     REASON
-----     ---          ---        ------     ------
52005     076/0018     01-168     ACRIM      Power ON
52008     076/0342     01-169     SUSIM      Power ON (Start)
52013     076/1257     01-170     PEM        Power ON - Day Only
52015     076/1449     01-169     SUSIM      Power ON (Continuation)
52015     076/1539     01-169     SUSIM      Power ON (Completion)
52034     077/2113     01-171     SUSIM      Motor Commands
52045     078/1544     01-172     OBC/TAM    TAM Alignment
52047     078/1813     01-173     NBTR       NOOPS D-079
52050     078/0020     01-174     HALOE      Power ON PART 1
52055     078/0721     01-173     NBTR       NOOPS D-079
52058     079/1227     01-175     HALOE      Power ON, complete
52070     080/0722     01-176     NBTR       NOOPS D-080
52077     080/1919     01-077     NBTR       NOOPS D-081
52084     081/0617     01-177     NBTR       NOOPS D-081
52090     081/1553     01-179     OBC/TAM    Table 53 Update
52092     081/1920     01-178     NBTR       NOOPS D-082
52099     082/0617     01-178     NBTR       NOOPS D082
52107     082/1921     01-180     NBTR       NOOPS D083

___________________________________________________________________________

                            APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                       Week ending 23 March 2001

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 23 March 2001

                    CLOCK DRIFT RATE ADJUSTMENTS

ORBIT     TIME     CLOCK RATE CHANGE
-----     -----     -----------------
-None this report period
_______________________________________________________________________


                           APPENDIX D
                UARS BATTERY PERFORMANCE DATA
                  Week ending 23 March 2001


     16 Mar 2001 - GMT Day 075 Beta = 01.5 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    +22.4/+0.0     -3.68/-4.94  +0.0/+0.0     13.0     0.000     0.0
2    +16.8/-89.6    +5.15/+4.19  +29.6/-13.6   25.3     1.020     20.4
3    +33.6/-44.8    +3.87/+2.92  +28.8/-13.2   25.3     1.020     20.0


     23 Mar 2001 - GMT Day 082 Beta = 28.0 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    +39.2/+11.2    -3.05/-4.31  +0.0/+0.0     13.0     0.000     0.0
2    +16.8/-89.6    +6.11/+4.51  +28.8/-15.2   24.5     1.030     22.0
3    +33.6/-33.6    +5.15/+3.87  +28.8/-16.0   24.5     1.020     22.0


     V/T LEVEL CHANGES
ORB#            TIME          LVL FR-TO
----            ----          ---------
-no changes     V/T 5

______________________________________________________________________________

                                APPENDIX E
                      UARS ANOMALY REPORTS
                    Week ending 23 March 2001

                    NEW ANOMALY REPORTS GENERATED
AR NO.     SUBSYS     ORBIT     TIME        TTR     PROBLEM/DATA LOSS
------     ------     -----     ----        ---     -----------------
01-014     FOT        52091     081/1739    14170   Generic Late Acquisition
01-017     FOT        52056     079/0901            No AP for 1.5 hours

               ANOMALY CLOSURE INFORMATION RECEIVED
AR NO.     SUBSYS     ORBIT     TIME        TTR     PROBLEM/DATA LOSS
------     ------     -----     ----        ---     -----------------
01-017     FOT        52056     079/0901            No AP for 1.5 hours

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

                       OPEN ANOMALY REPORTS
AR NO.     SUBSYS     ORBIT     TIME        TTR     PROBLEM/DATA LOSS
------     ------     -----     ----        ---     -----------------
01-014     FOT        see list  Mar 01      14170   Generic Late Acquisition



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