UARS Weekly Status Report

4 December 1998





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                UARS WEEKLY STATUS REPORT - 04 DEC 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.

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

Nothing received.

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

     PEM/ZEPS was active between October 16 and October 30; PEM/AXIS
was active from November 16 to November 19 and November 27 to December 1.
During these times, PEM/ZEPS computed energy deposition from in situ electrons
and protons; PEM/AXIS computed energy deposition from an inversion of
measured X-rays.

     PEM is currently conducting tests of the OBC activation.  PEM activation
occurs during daylight only, when there is adequate power generated from 
the UARS solar array.  Currently, the PEM magnetometer and medium energy 
spectrometers (particles below 30 keV) activate correctly under OBC control.
Tests conducted on the high energy particle spectrometers (HEPS -- particles 
greater than 30 keV) have had limited success, and are still failing to enable 
the instrument correctly.  Instrument high voltage correctly activates as a 
stand-alone function, but low voltage microprocessor adjustments generate 
instrument errors.  Additional tests are scheduled.  HEPS science data between 
October 1 and November 15 should be considered invalid and not used.

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

Nothing received.

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

After MLS was reactived successfully on Nov 21 a spacecraft power shortage
forced MLS to reduce power to allow the batteries to reach full state of
charge. On Nov 22 network problems at Goddard prevented monitoring of the MLS
instrument. After these problems persisted for several days the MLS Operations
team was forced to power off MLS early to avoid any unnecessary risk to the
instrument.

The instrument is now off as scheduled.

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

Nothing received.

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WINDII
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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 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.
              0 days HAL (4.80) PROD (L2-L3) (89R-62C=27L)
              0 days HAL (4.80) PROD (L3)    (1874R-1429C=445L)
             41 days SOL (4.62) PROD (L2-L3) (2313R-2152C=161L)
            270 days SUS (7.00) PROD (L1)    (2540R-777C-1F=1762L)
              6 days CLA (7.00) ENG  (L1-L3) (24R-21C=3L)
 
UCSS developers are in the process of loading database archival information for 
SOLSTICE to determine any correlation factors in SOLSTICE processing time
degradation. 

CDHF preventive maintenance for the systems and peripherals is due in December.
It is scheduled for Tuesday 12/15/98.  

UARS CDHF completed Y2K Time Shift testing on a subset of the
UARS CDHF Cluster. UCSS RSS services succesfully passed Y2k testing.  

The CDHF is in the configuration phase of the UOAS, UCSS, MSS, and NRT
installation. This phase should not require machine downtime.

CDHF pending software upgrades: IDL 5.1, OpenIngres, UCSS 10.1, MSS 4.1,
NRT 2.5, UOAS 5.4  
                  
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FOT
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REPORTING PERIOD

This report covers 21 November 1998 (Orbit 39299, GMT Day 325) through 26 
November 1998 (Orbit 39417, GMT Day 331).


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         325/0124      39314      On (PMON)
             MLS         325/0124      39314      On
             HRDI        325/1916      39325      Off
             WINDII      325/2049      39326      Off
             HRDI        327/1735      39354      On (PMON)
             HRDI        328/0959      39364      Off
             MLS         329/0324      39375      Off
             WINDII      329/1528      39383      On
             PEM         331/0006      39403      AXIS On

The beta angle ranged between 73.1 degrees to 65.8 degrees for this report 
period. The beta angle is now decreasing toward a minimum angle of -1.0 
degrees on 13 December 1998 (DOY 347).

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 1.2 degrees C.  Additional battery performance data 
for each battery on 20 November 1998 and 27 November 1998 are provided in 
Appendix D.

The clock error ranged from -10.2 to 12.4 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
%     HRDI    06
%     MLS     07
%     PEM     02
%     WINDII  03

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

%     FOT     08

Nine (9) Anomaly Report remained OPEN at the end of this report period (see 
Appendix E).

TRANSPONDER FREQUENCIES:
Transponder A:  98/286  -  2287.496917
Transponder B:  98/300  -  2287.498980


GROUND SYSTEM OPERATION

Four (4) 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 98/330 show the observatory data loss to be 
21 hours, 39 minutes, 40.020 seconds (an increase of 24 minutes and 50.752 
seconds since last report period).  This is a 0.0344 percent data loss 
which equals a 99.9656 percent data capture for the mission.

The increase of 24 minutes and 50.752 seconds occurred over six (6) days:

7 1.632 seconds on Day 324 due to hits in data (IP);
7 0.800 seconds on Day 325 due to hits in data (IP);
7 24 minutes and 37.120 seconds on Day 326 due to IP dropout and 
insufficient overlap;
7 1.248 seconds on Day 327 due to hits in data (IP);
7 8.416 seconds on Day 328 due to hits in data (IP); and
7 1.536 seconds on Day 329 due to hits in data (IP).

The 24 minutes and 37.120 seconds data loss on Day 326 occurred in Orbit 
20396.  This was an added pass as the result of another IP problem in the 
previous contact.  Because this was an added pass, the backup stored 
commands placing the recorder in record were not present.  The IP problem 
occurred during playback and precluded immediate corrective action by the 
operators to save the downlinked data.


OTHER SIGNIFICANT EVENTS

UARS SATELLITE OPERATIONS

WINDII has requested support for Polar Mesospheric Cloud (PMC) observations 
during their next southward viewing period.  WINDII is currently schedule 
for observations 19-23 December 1998 and 6-10 January 1999.  Both of these 
periods can potentially provide PMC observations.  The support required is 
a roll down of the cold side by 0.5 degrees in order to lower the bottom of 
WINDII's fields of view to an altitude where PMCs can be seen in the 
southern hemisphere; a procedure that has been followed several times in 
the past.  This request is being coordinated with other UARS instruments.

The UARS  FOT has started preparing the 0.5 degrees (colds side down) roll 
procedure to be executed in December 1998 and January
1999.

The UARS FOT has started preparing the clock change procedure for the leap 
second adjustment to be made 1 January 1999.

Investigating 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

UARS Test and Training Simulator (UTTS) - No change.

User Planning System (UPS) - No change.

Multi Satellite Operations Control Center (MSOCC) - No change.

Command Management System (CMS) - No change.

Flight Dynamics Facility (FDF) - see CMS paragraph.


IP NETWORK TESTING - Complete


UARS PROPULSION MODULE B/D THRUSTER LINE FILL

The UARS FOT plans to begin testing of the Orbit Adjust Maneuver on the 
UTTS(simulator) in early December 1998.  Two versions will be tested; one 
with B/D thrusters and another A/C thrusters.  The next orbit adjust will 
not be needed until late 2000 or later if the altitude limits are changed 
again.


UARS RE-ENGINEERING - TELEMETRY PROCESSING

Testing of the Trending System v.1.1 release (CM-0009) continued.  More 
DR's and ER's are being generated.


MEETINGS

The November battery telecon was held on 24 November 1998 at 1:00 PM EST.  
Only TOPEX and UARS participated.  The December 1998 meeting date will not 
be selected until after the Thanksgiving Holidays.  The UARS batteries are 
operating normally for the age of the batteries and continuing to support 
the mission to 22 percent DOD with good end of night voltage.  



FUTURE SIGNIFICANT EVENTS

The next UARS Yaw Around Maneuver is scheduled for scheduled for 13 
December 1998.

The United States Naval Observatory (USNO) issued  a Time Service 
announcement advising that the International Earth Rotation Service (IERS) 
will retard UTC time by 1.0 second at the end of December 1998. This means 
the addition of one leap second as the last second of 1998.

The next annular solar eclipse will occur on 16 February 1999 over the 
Indian Ocean, Australia and the South Pacific Ocean.


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 27 November 1998

ORBIT         AOS         NO.    SUBSYS     REASON
-----         ---         ---    ------     -------  
39314     325/0124     98-458     PEM     Power ON (PMON CNTRL)
39314     325/0124     98-459     MLS     Power ON
39324     325/1728     98-460     MLS     Filter Banks 2 & 4 OFF
39325     325/1916     98-461     HRDI    Power OFF  S/C Low Pwr
39326     325/2049     98-462     WINDII  Power OFF  S/C Low Pwr
39329     326/0153     98-463     MLS     MLS stop scan
39333     326/0805     98-464     HRDI    Reposition  telescope
39333     326/0805     98-465     MLS     FB 2 & 4 on, Run mode
39343     327/0014     98-466     OBC     Clk Adj fr 0.00 to 20.6 msec/day
39354     327/1735     98-467     HRDI    HRDI Day-Only Ops
39364     328/0959     98-468     OBC     Clk Adj fr 20.6 to 41.2 msec/day
39364     328/0959     98-469     HRDI    Safehold - high TBAT temp
39364     328/0959     98-470     MLS     Stop scan  -  high SCANACT temp
39377     329/0635     98-469     HRDI    Safehold - high TBAT temp
39364     329/0959     98-470     MLS     Scanner  OFF
39375     329/0324     98-471     MLS     Power OFF
39383     329/1528     98-472     WINDII  Power ON
39392     330/0641     98-469     HRDI    Safehold - high TBAT temp
39403     331/0006     98-473     PEM     Power AXIS ON 
39408     331/0825     98-474     WINDII  Error clear
39416     331/2032     98-475     OBC     Clk Adj fr 40.2 to 20.6 msec/day

_______________________________________________________________

                               APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 27 November 1998

MNEMONIC      STATE      DESCRIPTION                     ORBITS
---------     -----      ------------                    ------
HRPTSBARTMP    Y-LO   Telescope Barrel Temp            39313-14,332-336,                    
                                                       361-378,391-393,                      
                                                       414-417
HRIFESURVTMP  Y-HI    Iterferometer Survival Temp      39327,328,340     
HRRADTEMP     Y-HI    Interferometer Radiator Temp     39328
QTZEPSIF1     Y-LO    I/F Plate Aft                    39400
          

The following ALERT occurrences were detected:

MNEMONIC                DESCRIPTION                      ORBITS
---------             ------------                      ------
WISCLSR        WINDII Laser operating(nominal)         39395
WIERRLIMIT     WINDII Software Error Code = E03        39408


_______________________________________________________________

                               APPENDIX C
                 CLOCK & SOLAR ARRAY RATE CORRECTIONS
                      Week ending 27 November 1998


                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT              TIME                 CLOCK RATE CHANGE
     -----              ----                 -----------------
     39343     327/00:27 (23 Nov 98)     from 41.2 to 20.6 msec/day
     39364     328/10:10 (24 Nov 98)     from 20.6 to 41.2 msec/day
     39416     331/20:39 (27 Nov 98)     from 41.2 to 20.6 msec/day


_______________________________________________________________

                               APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                      Week ending 27 November 1998


     20 Nov 1998 - GMT Day 324 Beta = 73.1 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  +100.8/+78.4  -3.05/-4.31   +0.0/ +0.0    16.8    0.000    0.0
2   +16.8/-22.4  +3.87/+1.97  +18.8/-15.6    27.0    1.034   16.0
3   +78.4/+11.2  +2.60/+1.34  +18.4/-15.2    26.9    1.033   15.5


     27 Nov 1998 - GMT Day 331 Beta = 65.8 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/+67.2  -3.05/-4.62   +0.0/ +0.0    16.8    0.000    0.0
2   +11.2/-33.6  +3.87/+2.60  +22.8/-15.2    26.7    1.030   17.3
3   +44.8/ 0.0   +2.92/+1.66  +22.0/-14.4    26.7    1.031   16.7


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



                               APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 27 November 1998


                     NEW ANOMALY REPORTS GENERATED
  AR NO.   SUBSYS   ORBIT      TIME       TTR       PROBLEM/DATA LOSS
  ------   ------   -----      ----       ---       -----------------
98-109     FOT      39323     325/1546    N/A     TAC/OBC Dump problems
98-110     FOT      39325     325/1916    N/A     TAC/OBC Dump problems
98-111     FOT      39341     326/2052    20396   UARS IP Desktop down
98-112     FOT      39341     326/2204    20396   IP Desktop down
98-113     FOT      39342     326/2243    N/A     Commanding/AP Problems
98-114     FOT      39354     327/1735    N/A     TAC/OBC Dump Problems
98-092     FOT      39407     331/0642    14170   Generic Late Acquisition
98-092     FOT     39415     331/1858     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


                          OPEN ANOMALY REPORTS
  AR NO.   SUBSYS      ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------      -----      ----       ---      -----------------
98-092     FOT        Nov 98     See List   14170    GENERIC LATE ACQ
98-107     FOT        39308     324/16:40            TAC 2 PROB     
98-108     FOT        39309     324/17:23            TAC PROBLEMS
98-109     FOT        39323     325/15:46            TAC PROBLEMS
98-110     FOT        39325     325/19:16            TAC PROBLEMS
98-111     FOT        39341     326/20:52   20396    DESKTOP DOWN
98-112     FOT        39342     326/22:04   20396    DESKTOP DOWN
98-113     FOT        39342     326/22:43            CMD PROBLEMS
98-114     FOT        39355     327.17:35            TAC/DMP PROBLEMS


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