UARS Weekly Status Report

13 March 1998





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                UARS WEEKLY STATUS REPORT - 13 March 1998

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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 was turned off on March 11.  It is expected to resume operations
on March 17.  Otherwise, SUSIM successfully gathered its normal solar,
offset, and occultation scan data during this past week without apparent
problems.

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

     PEM/AXIS was activated from March 2 through March 6.  During this time,
AXIS produced energy deposition profiles from inverted electrons obtained using
the AXIS X-ray measurements.

     PEM is awaiting evaluation by GSFC of its proposed activation procedure.
The minimal configuration for PEM AUX activation is the zenith VMAG, MEPS1, 
MEPS2, and HEPS1 units, only.  This configuration is driven by the capabilities 
of the spacecraft OBC and may increase if OBC program area increases.  PEM 
activation is proposed to be OBC driven when there exists plenty of power to 
operate PEM.  It is anticipated that the OBC will activate PEM on the daylight 
portions of every orbit.

     PEM will support the UARS Science team meeting March 16 through March 18.
The PEM PI, J. D. Winningham, will give a status update on PEM.  PEM will have
two Oral presentations on Monday, March 16: "The UARS PEM Energetic Particle 
Climatology - Status and Applications," (J. R. Sharber, R. A. Frahm, G. Crowley,
A. J. Ridley, R. Link, J. D. Winningham, E. E. Gaines, R. W. Nightingale, 
D. L. Chenette, and W. R. Keith) and "Particle Effects on the Middle Atmosphere
Modeled using the Parallelized TIME-GCM," (G. Crowley, A. J. Ridley, 
J. D. Winningham, R. Link, R. A. Frahm, J. R. Sharber, R. G. Roble, A. Richmond,
and J. M. Russell III).  In addition, there will be a PEM poster on Tuesday, 
March 17: "A Global PEM Electron Precipitation Climatology for the Kp Index: 
Work in Progress," (R. A. Frahm, G. Crowley, J. R. Sharber, J. D. Winningham, 
R. Link, A. J. Ridley, E. E. Gaines, D. L. Chenette, B. J. Anderson and 
T. A. Potemra).  All these PEM presentations deal with creating a PEM particle 
based climatology.

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

Nothing received.

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

MLS was reactivated successfully on Mar 12, in the reduced 85 watt power mode.
MLS instrument operations have continued flawlessly.  MLS is scheduled to
operate through Mar 16.

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

HRDI was turned off end of day March 11.  We expect to be turned back on
March 17.

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

Nothing received.

***********
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.

We welcome Robin Gordon as the new member of the UARS Mission 
Planning Group here at GSFC.   

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

The CDHF has received a total of 377 CD-ROM requests as of 13-March-1998.
There was one order received and shipped.

The CDHF previewed DAAC data created in the month of January, 1998 for
HALOE, HRDI, PEM, NMC, and UKMO.
                          
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.           
                  25 days PEM (3.32) PROD (1379R-1004C=375L)
                 129 days MLS (4.90) PROD (1297R-933C=364L)
                  11 days CLAES (7.0) ENG (19R-19C=0L)
                   0 days HAL (4.80) ENG  (2R-0C=2L)
                   2 days SEN (5.0) PROD  (2R-2C=0L)
              
The CDHF continued development of a list of Year-2000 compliant software
needed by the CDHF.

Pending software upgrades: IDL 5.0, OpenIngres, UCSS. 
                  
***********
FOT
***********

REPORTING PERIOD

This report covers 27 February 1998 (Orbit 35316, GMT Day 058) through 06 
March 1998 (Orbit 35434, GMT Day 065).


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
     MLS         059/0108   35331     On
   WINDII        060/0220   35346     On
    PEM          061/0116   35361     AXIS on
    MLS          062/2342   35390     Off
   HALOE         063/0135   35391     On
    PEM          065/2222   35434     AXIS off

A summary of Instrument operations supplied by the Mission Planning Group 
for the month of February 1998 is contained in Appendix F, UARS Instrument 
Operations Summary.

The beta angle is now increasing toward a maximum angle of 54.5 degrees on 
15 March 1998 (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 25.4 V end-of-night (EON) load bus voltage.  
Battery temperatures are stable with a temperature delta between Battery 2 
and Battery 3 of 1.1 degrees C.  Additional battery performance data for 
each battery on 28 February 1998 and 06 March 1998 are provided in Appendix 
D.

The clock error ranged from -11.0 to +10.2 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            =     02
%     OUT-OF-LIMITS     =     04

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
%     HRDI       02
%     MLS        02
%     PEM        02
%     SOLSTICE   01
%     WINDII     02


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

%     FOT     03

TRANSPONDER FREQUENCIES:
     Transponder A:  98/041  -  2287.497104
     Transponder B:  98/042  -  2287.499330


GROUND SYSTEM OPERATION

Two (2) operational support problem(s) 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 98/064 show the observatory data loss to be 
20 hours, 42 minutes, 7.540 seconds (no change since last reported).  This 
is a 0.0366 percent data loss which equals a 99.9634 percent data capture 
for the mission.

FOT continues to investigate the feasibility of participating in the IP 
Forward Link testing.  The methodology and requirements for performing a 
command loop-back test is currently under investigation.

The inability to transmit commands to the UARS Test and Training Simulator 
(UTTS) was first observed on 24 February 1998.  Investigation of this 
problem which impacts AP software testing, etc. continues.

The FOT is investigating the possibility of utilizing the RUPS (located in 
MSOCC) to record high speed NBTR playbacks, and subsequently play them back 
at a slower rate to the UARS re-engineering ground system.  Apparently this 
is not an operational capability, has been attempted in the past, but 
knowledgeable personnel are no longer available.

Testing of the latest AP software (modified to support a reduced ATC load) 
is on hold due to the UTTS problem.

Operational processing of level-0 telemetry analysis files continues in 
parallel on both the UMPGAL (new MPG Alpha machine) and CDHF computer 
systems.  No level-0 file transfer failures (between CDHF and UMPGAL) 
occurred this week.

FOT assisted in updating the magnetometer model on the UTTS for future 
orbit adjust simulations.  Updated model coefficients generated from 
spacecraft data were provided.

UARS playback data will be captured on the White Sands Ground Terminal 
line-outage recorders during the planned GFSC building 23 power outage from 
about 12 pm on Friday, 20 March 1998, until about 12 pm on 23 March 1998.  
The UARS elements affected are the Data Capture Facility, Level-0 Data 
Processing, Central Data Handling Facility (CDHF), and possibly the Near 
Realtime Data (NRT) flow.  Playback data quality will be monitored at White 
Sands Ground Terminal (WSGT) using the WSGT Data Quality Monitor (DQM).  
All recorded data will be replayed to building 23 and processed following 
the outage.


OTHER SIGNIFICANT EVENTS

Work on the upgrade of the OBC Power Monitor (PMON) software continued.  
Work in this area was also impacted by the UTTS command problem.  OBC 
software development can not be done on the UTTS VAX when the UTTS is 
active for troubleshooting.

Orbit Adjust planning has been initiated.  The tasks have been identified 
and a schedule developed.

A plan to cycle spacecraft heaters during the planned powering OFF of the 
SSPP instruments (starting DOY 071) was initiated.  Previous experience 
indicated that a revision to the plan was desirable. For this reason, the 
FOT has revisited and carefully thought out the necessary heater commands 
(which will be controlled via RTSs) to perform the heater cycling, without 
adversely impacting power.

FOT is supporting CNMOS in their efforts to make necessary software changes 
(MSOCC, CMS, DCF, etc.) to support the year 2000 rollover.

Monitoring of the magnetic field model performance continues.

FOT continues to improve a Power Profile for UARS based on the current 
status of the Modular Power System.

FOT continues to support the new UARS ground system re-engineering effort.


MEETINGS

No UARS Battery telecon was held this week.  The next telecon has not been 
scheduled.


FUTURE SIGNIFICANT EVENTS

All building 23 power will be down during the weekend of 20-23 March 1998 
to perform work on the building power supply.  The building 23 systems will 
be unavailable from about 12 pm on Friday, 20 March 1998, until about 12 pm 
on 23 March 1998.

The next UARS Yaw Around Maneuver is currently scheduled for 02 April 1998.

A second building 23 power outage is scheduled from about 12 pm, 24 April 
1998, until about 12 pm, 27 April 1998.

UARS Flight Operations plans to attend the Program Experience portion of 
the Space Power Workshop at JPL in April 1998.  UARS FOT plans on 
presenting an overview of the UARS batteries and their performance.

The UARS orbit altitude is dropping slowly and a drag makeup orbit adjust 
is targeted for 05 August 1998.


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 F, UARS Instrument Operations Summary



                               APPENDIX A
                       REAL-TIME COMMAND SHEETS
                      Week ending 06 March 1998

ORBIT      AOS         NO.    SUBSYS                 REASON
-----      ---        ---     ------                -------  
35333   059/0712     98-072    MLS       Power ON
35338   059/1210     98-073    OBC       Clk Adj 20.6 to 0.0 msec/day
35344   059/2231     98-074    HRDI      Htr Cycle 300 to 150 amp min
35346   060/0110     98-075   WINDII     Power ON
35361   061/0116     98-076    PEM       AXIS-Power ON
35363   061/0451     98-077  SOLSTICE    Reload D060 Micro-Loads
35390   062/2357     98-078    MLS       Power OFF
35391   063/0135     98-079   HALOE      Power ON
35392   063/0313     98-080   HRDI       Htr Cycle to 100 amp min
35398   063/1235     98-081    OBC       Clk Adj 0.00 to 20.6 msec
35425   065/0744     98-082    OBC       Clk Adj 20.6 to 0.0 msec/day
35434   065/2222     98-083   WINDII     Power OFF
35434   065/2222     98-084    PEM       Power OFF AXIS


_______________________________________________________________

                               APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 06 March 1998

MNEMONIC      STATE      DESCRIPTION                    ORBITS
---------     -----      ------------                   ------
WIEUTEMP     Y-LO   WINDII EU Temperature         35330-45
QTSISAIF     Y-LO   Baseplate by SISA I/F         35330-45,50-60,66
HRPSEQBIMON  Y-HI   HRDI PSE Quiet Bus I Monitor  35337-8,42,53,58,60,85
WIEUTEMP     Y-LO   WINDII EU Temperature         35346

The following ALERT occurrences were detected:

MNEMONIC                DESCRIPTION                     ORBITS
---------               ------------                    ------
HGCMDERR     HGA CMD ERROR (Due to OMNI Support)  35377
WISRCBBS     WINDII Broadband Source Operating    35378
          



                               APPENDIX C
                 CLOCK & SOLAR ARRAY RATE CORRECTIONS
                      Week ending 06 March 1998

                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT              TIME                 CLOCK RATE CHANGE
     -----              ----                 -----------------
     35338     059/12:13 (28 Feb 98)     from 20.6 to 00.0 msec/day
     35398     063/12:44 (04 Mar 98)     from 00.0 to 20.6 msec/day
     35425     065/07:50 (06 Mar 98)     from 20.6 to 00.0 msec/day


_______________________________________________________________

                               APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                      Week ending 06 March 1998

     28 Feb 1998 - GMT Day 059 Beta = 13.1 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  +728.0/+728.0   -3.05/-4.31   +0.0/ +0.0     18.6    0.000    0.0
2   +89.6/    0.0  +7.09/+4.51  +32.0/-15.6     24.2    1.018    23.6
3   +44.8/-16.8    +5.79/+3.23  +31.2/-16.0     24.2    1.022    23.0

     06 Mar 1998 - GMT Day 065 Beta = 36.5 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   +728.0/+728.0   -3.68/-4.31   +0.0/ +0.0   18.4     0.000    0.0
2    +95.2/  -5.6   +6.11/+4.83  +30.4/-16.0   25.6     1.026    22.4
3    +61.6/ -11.2   +5.15/+3.87  +29.6/-16.0   25.4     1.026    21.7


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



                               APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 06 March 1998

  AR NO.   SUBSYS    ORBIT      TIME      TTR     PROBLEM/DATA LOSS
  ------   ------    -----      ----      ---     -----------------
98-008    FOT     35354    060/1353    14170   Generic Late Acquisition
98-009    FOT     35364    061/0634    14170   Generic Late Acquisition
98-010    FOT     35431    065/1724     N/A    Error in CMS file transfer


                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



_______________________________________________________________
                               APPENDIX F
                   UARS INSTRUMENT OPERATIONS SUMMARY
                      Week ending 06 March 1998


              INSTRUMENT SUMMARY FOR MONTH OF February 1998 (hours)


                                    UNPLANNED      UNSCHEDULED
                 ON        OFF         OFF             OFF     
                                   (Insufficient   (Other than
Instrument    (Actual) (Scheduled)       Power)   Power Problem)  COMMENTS
----------     ------  ----------- -----------    ------------- -----------

ACRIM         672          0            0             0

HALOE         177        495            0             0

HRDI          262        410            0             0

MLS           370        302            0             0

PEM (axis)     24        648            0             0

PEM (zeps)     47        625            0             0

PEM (neps)      0        672            0             0

SOLSTICE      672          0            0             0

SUSIM         672          0            0             0

WINDII        247        425            0             0


Cold side of spacecraft was facing northward:  24.5 days
Cold side of spacecraft was facing southward:   3.5 days