UARS Weekly Status Report

30 January 1998





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                UARS WEEKLY STATUS REPORT - 30 January 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 successfully gathered its normal solar, offset, and occultation
scan data during this past week without apparent problems. Also, a
series of SSPP gridded offset maneuvers were performed using the SUSIM
lower spectrometer.

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

     PEM/AXIS was active from January 18 through January 22.  PEM produced 
energy deposition profiles from electrons inverted from the AXIS X-ray 
measurements taken during this time.  PEM/AXIS and PEM/ZEPS (zenith boom
spectrometers and magnetometer) became active on January 29.  PEM is
now producing energy deposition profiles from in situ electrons, in situ ions,
and electrons inverted from measured x-rays.

     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.

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HALOE 
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Nothing received.

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

The MLS instrument has been powered off since Dec 27. MLS is scheduled to
begin north viewing operations on Jan 20.

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

Nothing received.

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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.

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

The CDHF has received a total of 365 CD-ROM requests as of 30-January-1998.
There was one order received and one order shipped.

THE CDHF loaded DAAC data for HALOE, HRDI, PEM Versions 3 and 4, NMC, and UKMO 
created in the month of November 1997.
                     
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-854C=525L)
                 121 days MLS (4.90) PROD (1344R-198C-3F=1146L)
                  0 day CLAES (7.0) ENG   (17R-1F=17L)
                  9 days WIN (5.10) ENG   (17R-17C=0L)

The CDHF will load December 1997 current day DAAC data in February 1998. 

The CDHF has disabled accounts that had been determined inactive.  
The accounts still continue to forward email, if they have 
forwarding set up. The Group Rep can re-establish a desired account.
  
Pending software upgrades: IDL 5.0, OpenIngres. 

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

REPORTING PERIOD

This report covers 09 January 1998 (Orbit 34597, GMT Day 010) through 16 
January 1998 (Orbit 34700, GMT Day 016).


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     018/0102     34717     AXIS on
     MLS     020/0341     34749     On
     PEM     022/2332     34791     AXIS off
     MLS     022/2332     34791     Off

The beta angle is now increasing toward a maximum angle of 72.6 degrees on 
05 February 1998 (DOY 036).

A series of SSPP gridded offset maneuvers requested by SUSIM was performed 
on GMT days 017 through 022.  The offsets utilized the 5 and 10 arcminute 
intervals, as opposed to the 15 and 30 arcminute intervals.

Two Rmanually generatedS Stellar Offset maneuvers requested by SOLSTICE 
occurred on GMT days 020 and 022.

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 24.2 V end-of-night (EON) load bus voltage.  
Battery temperatures are stable with a temperature delta between Battery 2 
and Battery 3 of 1.2 degrees C.  Additional battery performance data for 
each battery on 17 January 1998 and 23 January 1998 are provided in 
Appendix D.

The clock error ranged from -10.0 to +10.1 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            =     01
%     OUT-OF-LIMITS     =     06

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

%     FOT     04
%     HRDI    03
%     MLS     02
%     PEM     02

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

%     FOT     01

TRANSPONDER FREQUENCIES:
     Transponder A:  98/020 - 2287.497001
     Transponder B:  98/014 - 2287.498785


GROUND SYSTEM OPERATION

One (1) 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 98/022 show the observatory data loss to be 
20 hours, 41 minutes, 35.316 seconds (an increase of 01.056 seconds since 
last reported).  This is a 0.0372 percent data loss which equals a 99.9628 
percent data capture for the mission.

The increase of 01.056 seconds occurred on Day 020 and was the result of 
hits in the data.

No testing of the new CMS software release (R7B1V2) occurred this week.

A simulation of a reduced size ATC load was performed this week.  The test 
was conducted by loading the UTTS OBC with a 768-command ATC load. The new 
OBC image accepted the reduced ATC load but a large amount of miscompares 
(2263) were revealed during the dump comparison process. The first 768 
words compared correctly.  However, most of the words in locations 768-3071 
miscompared apparently because the ground system logic built the ground 
reference image as though it expected a 1024-command ATC load.  A meeting 
with the programmer was conducted on 21 January 1998 in which the test 
results were discussed.

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.

The MS434 Rline tapS of the UARS real-time I channel data to the TOMS 511 
line appears to be functioning well.  The TOMS/UARS re-engineering team 
informed UARS that the UARS data looked good on their test system.

The FOT has finalized the details for participating in the IP return-link 
telemetry testing.  The FOT was informed by MSOCC (Tom Marsh) that the IP 
conversion devices were installed into the MSOCC area on 21 January 1998.  
The MSOCC DOC operators have been informed of the special procedures which 
must be executed to configure the AP to receive IP data from NASCOM.  UARS 
plans to start viewing the IP data on 27 January 1998.

The tape loading mechanism on the UCMS 4mm tape drive (prime system) broke 
on 18 January.  The tape drive was repaired on 22 January.  Three daily 
incremental saves and one MPG save were missed.

SUSIM operations submitted a request for the FOT to schedule six additional 
SOLSTICE offsets for the week of 01 February 1998.  Both SOLSTICE 
operations and the FOT agreed to this request.  One offset will take place 
each day beginning with GMT Day 031 and ending with GMT Day 036.

A request for another set of series of SSPP gridded offset maneuvers, to 
occur on GMT Days 024-029, was also submitted by SUSIM operations.


OTHER SIGNIFICANT EVENTS

Work on the upgrade of the OBC Power Monitor (PMON) software continued.  A 
significant amount of coding has been completed, only to discover the 
redesigned software now far exceeded its memory allocation.  Working on 
second iteration of redesign to reduce the code size to within the 
available memory space.

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.

A recent projection of the orbit attitude by the Flight Operations Team 
(FOT) indicates that an orbit adjust will probably will not be required 
until 1999.


MEETINGS

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



FUTURE SIGNIFICANT EVENTS

The next UARS Yaw Around Maneuver is currently scheduled for 25 February 
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 
will probably be required in 1999.


FACILITIES

no change


PERSONNEL CHANGES

no change


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 January 1998

ORBIT       AOS         NO.   SUBSYS         REASON
-----       ---        ---    ------         -------  
34694     016/1202   98-015     MPS   V/T Level change to 6
34695     016/1332   98-016     MPS   V/T Level change to 5
34697     016/1721   98-017     MPS   Reset BATSOC to 100
34717     018/0102   98-018     PEM   Power ON AXIS
34746     019/2249   97-019    HRDI   Heater delay to 200 Amp. mins.
34749     020/0341   98-020     MLS   Power ON
34749     020/0432   98-021    HRDI   Heater Delay to 25 amp-min
34759     020/2112   98-022    HRDI   Heater Delay to 100 amp-min
34784     022/1309   98-024     OBC   Clk Adj fr 20.6 to 0.00 msec/day
34791     022/2332   98-025     PEM   PEM AXIS Power OFF
34791     022/2332   98-026     MLS   Power OFF


_______________________________________________________________

                               APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 23 January 1998

MNEMONIC      STATE      DESCRIPTION                       ORBITS
---------     -----      ------------                      ------
ACTEMPANA2     Y-LO   Temp Sensor Electronics            34696-97
HRIFESURVTMP   Y-HI   HRDI Interferometer Survival Temp  34755,56
HRPSEQBIMON    Y-HI   HRDI Quiet Bus Current Monitor     34711,20,56
QTSISAIF       Y-HI   SSPP Baseplate by SISA I/F         CONTINUOUS
SOSTMPRNTRN    Y-LO   SOLSTICE Temperature Entrance      34696-98
WIEUTEMP       Y-LO   WINDII EU Temperature              CONTINUOUS


The following ALERT occurrences were detected:

MNEMONIC                DESCRIPTION                       ORBITS
---------               ------------                      ------
OBSZ1OOL     UFLTR Z1 Residual Exceeded 100 Arcsec         34695               



                               APPENDIX C
                 CLOCK & SOLAR ARRAY RATE CORRECTIONS
                      Week ending 23 January 1998

                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT              TIME                 CLOCK RATE CHANGE
     -----              ----                 -----------------
     34763     021/02:59 (21 Jan 98)     from 00.0 to 20.6 msec/day
     34784     022/13:18 (22 Jan 98)     from 20.6 to 00.0 msec/day


_______________________________________________________________

                               APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                      Week ending 23 January 1998

     17 Jan 1998 - GMT Day 017 Beta =  4.0 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   +728.0/+728.0  -3.05/-4.62  +0.0/ +0.0   18.6    0.000    0.0
2   +134.4/  +0.0  +6.11/+5.15 +32.0/-14.4   24.5    1.025   22.6
3    +89.6/  +0.0  +4.83/+3.87 +30.4/-15.2   24.5    1.020   21.9

     23 Jan 1998 - GMT Day 023 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   +728.0/+728.0  -3.05/-4.31  +0.0/ +0.0   18.6    0.000    0.0
2    +89.6/  +0.0  +6.44/+5.15 +32.0/-16.4   24.2    1.022   23.2
3    +67.2/  -5.6  +5.47/+3.87 +31.2/-16.8   24.2    1.024   22.5


     V/T LEVEL CHANGES
ORB#     TIME          LVL FR-TO
-----  --------      ----------
      (no change)


_______________________________________________________________
                               APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 23 January 1998

  AR NO.   SUBSYS   ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------   -----      ----       ---      -----------------
  98-001    FOT     34729    018/2103    14170     Generic Late Acquisition


          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