UARS Weekly Status Report

25 JUNE 1999




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                UARS WEEKLY STATUS REPORT - 25 JUN 1999

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

SOLSTICE began one week of day only operations on Wednesday, June 23
(99174).
Normal operations will resume at the beginning of day 99181 (Wednesday,
June 30). 
Full solar data sets are retrieved during this time, however no stellar 
calibration observations are possible.

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

Nothing received.

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

ACRIM II continues to perform nominally. Total Solar Irradiance data products
have been updated on the http://www.acrim.com web page to include all of 
CY1998 daily mean results. 

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

HALOE continues successful operations with all engineering parameters
within nominal operating range.  HALOE science data products are of
excellent quality.

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

MLS was reactivated successfully on June 23 and is scheduled to operate 
through June 29.  

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

Nothing received.

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

WINDII is next scheduled for operation June 30 to July 9,
which will include PMC observations in the northern 
hemisphere.

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

The CDHF processed current day data through level 3 for all active
instruments. Additionally, CDHF personnel reprocessed: (R)= Requested
   (C) = Complete, (F)= Failed  (L) = Days remaining to reprocess.
       13 days CLA (7.0)  PROD (L1-L3)         (475R-61C-8F=406L)
         0 days GPI (4.05) PROD (MLS V5 3AL)    (39R-0C-1F=39L)
        52 days WIN (5.11) PROD (L1-L3)         (1540R-787C-5F=748L)

The CDHF continues to run GPI software against HRDI V4.4 3AL data. 
     
DAAC data for the month of April 1999 has been loaded into the DAAC
Transfer Tables for HALOE, NMC, PEM, and UKMO.
We will load May 1999 current day DAAC data in July 1999.
                    
CDHF pending software upgrades:  DEC AXP Fortran 6.5, DEC AXP OPEN
VMS 6.2, OpenIngres.

***********
FOT
***********

REPORTING PERIOD

This report covers 12 June 1999 (Orbit 42353 , GMT Day 163) through 18 June 
(GMT Day 169).


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
               PEM       164/0042     42369      AXIS-1 On
              HALOE      166/1330     42407      On
              HRDI       168/0439     42431      Off
              PEM        168/2354     42443      AXIS-1 Off
              HRDI       169/0057     42444      On

The beta angle ranged between the angles of 0.8 degrees to 22.7 degrees for 
this report period.  The beta angle is now increasing toward a maximum 
angle of 34 degrees on 26 June 1999 (DOY 177).

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 23.5 V end-of-night (EON) load bus voltage.  
Battery temperatures are stable with a temperature delta between Battery 2 
and Battery 3 of 1.0 to 1.3 degrees C.  Additional battery performance data 
for each battery on 11 June 1999 and 18 June 1999 are provided in Appendix 
D.

The clock error ranged from -8.0 to 0.2 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  =     03

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

%     HRDI     03
%     HALOE    02
%     PEM      02

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

%     FOT     00

No Anomaly Reports remained OPEN at the end of this report period (see 
Appendix E).

TRANSPONDER FREQUENCIES:
          Transponder A:  99/130  -  2287.496913
          Transponder B:  99/151  -  2287.499087


GROUND SYSTEM OPERATION

No 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 99/119 show the observatory data loss to be 
24 hours, 13 minutes, 08.340 seconds (an increase of 2.944 seconds since 
the last report period).  This is a 0.0357 percent data loss which equals a 
99.9643 percent data capture for the mission.

The increase of 2.944 seconds occurred over two (2) days:

7 1.088 seconds on Day 165 due to data hits,
7 1.856 seconds on Day 166 due to data hits.


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 end-to-end testing has been delayed until a new FORMATS software 
release can be made to accommodate the special Y2K planning aids.


MEETINGS

FOT attended the last weekly IMOC meeting on Wednesday 16 June 1999.




FUTURE SIGNIFICANT EVENTS

The next UARS Yaw Around Maneuver (reverse-to-forward) is scheduled for 10 
July 1999 (DOY 191).


PERSONNEL CHANGES

The FOT would like to welcome Ron Smilek to UARS.  Ron will be taking over 
for John Speer as the technical lead.



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 18 June 1999

ORBIT       AOS        NO.     SUBSYS         REASON
-----       ---       ---     ------         -------  
42369    164/0042    99-201    PEM     AXIS 1 ON
42407    166/1330    99-202    HALOE   Power ON Pt-1
42410    166/1944    99-203    HALOE   Power ON Pt-2
42431    168/0439    99-203    HRDI    Power OFF
42443    168/2354    99-204    HRDI    Microload to correct logic error
42443    168/2354    99-205    PEM     AXIS 1 OFF
42444    169/0057    99-206    HRDI    Power ON 

_______________________________________________________________

                              APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                        Week ending 18 June 1999

MNEMONIC         STATE      DESCRIPTION                       ORBITS
---------        -----      ------------                      ------
PECUPRITE        R-HI     PCU Primary Current Mon            42373 
HRIFESURVTMP     Y-HI     HRDI SURVIVAL HTR TMP              42433     
HRPSEQBIMON      Y-HI     HRDI PSE Quiet Bus Current Mon     42442,47-8


The following ALERT occurrences were detected:

MNEMONIC              DESCRIPTION                           ORBITS
---------             ------------                          ------
                    None this report period

_______________________________________________________________

                              APPENDIX C
                 CLOCK & SOLAR ARRAY RATE CORRECTIONS
                        Week ending 18 June 1999

                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT            TIME                    CLOCK RATE CHANGE
     -----            ----                    -----------------
     -No clock adjusts for this report period



                              APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                        Week ending 18 June 1999


     11 June 1999 - GMT Day 162 Beta = 0.8 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   -95.2/-117.6  -3.05/-4.94   +0.0/ +0.0   16.5    0.000    0.0
2   +67.2/-5.6    +5.47/+4.19  +30.4/-15.2   23.8    1.015   21.6
3   +28.0/-39.2   +4.51/+2.92  +29.6/-16.0   23.8    1.015   21.3


     18 June 1999 - GMT Day 169 Beta = 22.7 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   -95.2/-123.2  -2.73/-3.99  +0.0/ +0.0    16.5    0.000    0.0
2   +56.0/-5.6    +7.09/+5.15 +30.4/-15.2    23.8    1.021   22.7
3   +22.4/-50.4   +5.79/+4.19 +29.6/-16.0    23.7    1.024   22.5


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



                              APPENDIX E
                         UARS ANOMALY REPORTS
                       Week ending 18 June 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
  ------   ------    -----      ----       ---      -----------------
99-029     FOT     42317     160/1405     20954     Late Acq. PTP reset


              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
  ------   ------    -----      ----       ---      -----------------
99-028     FOT     see list    June 99     14170    Generic Late Acq

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