UARS Weekly Status Report

30 JULY 1999




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                UARS WEEKLY STATUS REPORT - 30 JULY 1999

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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.


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

SUSIM resumed operations on 7/26.  Subsequently, it gathered its normal
solar, offset, and occultation data without apparent problems. 

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

Nothing received.

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

     The PEM spectrometers continue to be active under PMON control.  While 
under PMON control, the PEM instrument computed energy deposition from its 
particle spectrometers.

     The FOT and the PEM team are completing close-out documentation on 
the HEPS Energy Processor trouble; however progress has been hampered 
with the departure of Peter Thomas.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Routine processing of instrument Daily Activity Plans continues  
with no problems.  The MPG continues to assist the Project 
Scientist with the scheduling of instrument operations. 

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

Nothing received.
                  
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FOT
***********

REPORTING PERIOD


This report covers 17 July 1999 (Orbit 42878, GMT Day 198) through 23 July 
(GMT Day 204).


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
                WINDII      200/1206     42915     On
                 PEM        202/2140     42951     AXIS Off
                ACRIM       202/2140     42951     Off
                SUSIM       202/2140     42951     Off
                WINDII      202/2140     42951     Off
                 MLS        203/0443     42955     On
                 HRDI       204/2102     42977     Reset

The beta angle ranged between the angles of 21.8 degrees to 50.4 degrees 
for this report period.  The beta angle is now increasing toward a maximum 
angle of 75 degrees on 31 July 1999 (DOY 212).

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 0.9 to 1.1 degrees C.  Additional battery performance data 
for each battery on 16 July 1999 and 23 July 1999 are provided in Appendix 
D.

The clock error ranged from 11.4 to -11.2 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.

%     ALERTS            =     00
%     OUT-OF-LIMITS     =     00

The following real-time command sheets were executed for the listed 
operational element(s) during this report period (see Appendix A). 

%     FOT      03
%     WINDII   02
%     HRDI     01
%     PEM      01
%     ACRIM    01
%     SUSIM    01
%     MLS      01

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

%     FOT     00

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

TRANSPONDER FREQUENCIES:
          Transponder A:  99/179  -  2287.496941
          Transponder B:  99/180  -  2287.498977


GROUND SYSTEM OPERATION

Zero (0) 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 99/203 show the observatory data loss to be 
24 hours, 54 minutes, 38.644 seconds (an increase of 20.576 seconds since 
the last report period).  This is a 0.0363 percent data loss which equals a 
99.9637 percent data capture for the mission.

The increase of 20.576 seconds occurred over three (3) day:

7 8.736 seconds on Day 198 due to DRC not covered,
7 0.640 seconds on Day 201 due to DRC not covered,
7 11.200 seconds on Day 202 due to no overlap.


OTHER SIGNIFICANT EVENTS

UARS SATELLITE OPERATIONS

FOT personnel are supporting the IMOC (SCS-21) development effort.  The 
current work is a continuation of the SCS-21 UARS implementation effort 
done last year which culminated in a level 1 demonstration.

The FOT continues to investigate the feasibility of a new PMON action to 
change battery V/T curves based on loading to mitigate battery risks in sun 
pointing safehold.

YEAR 2000 OPERABILITY SUPPORT

The FOT received a set of Y2K planning aids from FDF which will be used to 
facilitate UARS Y2K end-to-end testing.  Eleven 3-day planning aid files 
were received and processed by the FOT.  Two of these files did not process 
successful on the CMS due to either incorrect data, or invalid data 
formats.  FDF has been notified of the problems, and are in the process of 
correcting the files.


MEETINGS

FOT attended a meeting with GRO. FOT to discuss their recent anomalies and 
lessons learned for applications to UARS.


FUTURE SIGNIFICANT EVENTS

The next UARS Yaw Around Maneuver (forward-to reverse) is scheduled for 20 
August 1999 (DOY 232).


PERSONNEL CHANGES

None


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 July 1999

ORBIT       AOS          NO.      SUBSYS     REASON
-----       ---          ---      ------     -------  
42912     200/0655     99-243     OBC       Clk Adj  0.00 to 20.6 msec/day
42915     200/1206     99-241     WINDII    Power ON
42938     202/0059     99-244     OBC       Clk Adj  20.6 to 0.00 msec/day
42951     202/2140     99-245     AXIS      Power OFF
42951     202/2140     99-246     ACRIM     Power OFF
42951     202/2140     99-247     SUSIM     Power OFF
42951     202/2140     99-248     WINDII    Power OFF
42955     203/0443     99-249     MLS       Power ON
42970     204/0448     99-250     OBC       Clk Adj 0.00 to 20.6 msec/day
42977     204/2102     99-251     HRDI      HRDI RESET

_______________________________________________________________

                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                        Week ending 23 July 1999

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 July 1999

                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT            TIME                    CLOCK RATE CHANGE
     -----            ----                    -----------------
     42912     200/07:03 (19 July 99)     from 00.0 to 20.6 msec/day
     42938     202/01:09 (20 July 99)     from 20.6 to 00.0 msec/day
     42970     204/04:53 (23 July 99)     from 00.0 to 20.6 msec/day


                              APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                        Week ending 23 July 1999


     16 July 1999 - GMT Day 197 Beta = 21.8 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   -100.8/-123.2 -3.05/-4.31  +0.0/ +0.0    16.5    0.000    0.0
2    +44.8/-28.0  +5.79/+4.83 +30.4/-14.4    25.0    1.023   21.8
3    +28.0/-33.6  +4.83/+3.87 +29.6/-14.8    24.8    1.023   21.5


     23 July 1999 - GMT Day 204 Beta = 50.4 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   -106.4/-134.4 -3.05/-4.62  +0.0/ +0.0    16.5    0.000    0.0
2    +44.8/-22.4  +5.47/+4.19 +26.4/-16.0    25.1    1.021   21.0
3    +22.4/-50.4  +4.51/+3.23 +25.6/-15.6    25.0    1.023   20.7


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



                              APPENDIX E
                         UARS ANOMALY REPORTS
                        Week ending 23 July 1999


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


                 ANOMALY CLOSURE INFORMATION RECEIVED
  AR NO.   SUBSYS    ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------    -----      ----       ---      -----------------
                      None this report period


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


                   OPEN ANOMALY REPORTS
  AR NO.   SUBSYS    ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------    -----      ----       ---      -----------------
99-033     FOT   see list     July 99     14170     Generic Late Acq.
	 	SEVNTFW99/30