UARS Weekly Status Report

17 November 2000




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                UARS WEEKLY STATUS REPORT - 17 Nov 2000

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

SOLSTICE is in good health, collecting solar data on all available orbital
tracking periods and stellar calibration observations whenever possible.
Some special processing will need to be done to retrieve the solar data
during this week's yaw offset because of the SSPP's late acquisition of the
sun. With the return to nominal attitude, this is no longer a problem.

During our continued testing of the OA_SSPP_ATT engineering patch, we
discovered a deficiency and relayed that back to the CDHF and CSC
programmers.

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

SUSIM was unable to make any scans during the recent YAW offset period.
The reason was that SSPP operations were disrupted because of an
inability to plan for this situation.  Afterward, normal yaw orientation
was restored, SUSIM resumed daily solar scans of the sun during periods
of predicted telemetry.

We are preparing to begin the reprocessing the SUSIM UV spectral
irradiances to data version V21 in the next few weeks.

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

Nothing received.

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

     The PEM zenith spectrometers are activate in daylight mode.

     At the present time, PEM energy deposition from its spectrometers is not 
being generated.  Recent data configuration changes have affected PEM software 
causing multiple failures.  These failures are being reviewed by the PEM team.
In order to correct for new telemetry requirements, PEM will need to update 
processing code with a patch delivery.  The delivery patch may include changes 
which would allow the PEM software to execute on a DEC Alpha machine.  GSFC is
helping PEM with some DEC Alpha particulars which have caused PEM level 3
code to fail on DEC Alpha machines (software below level 3 executes on the
DEC Alpha).  

     The PEM team is working on replacing the PEM:: machine with a DEC Alpha 
machine to be called PEM2K::.  PEM:: is now over 10 years old and its hardware 
is now very difficult and costly to maintain.  PEM:: is also showing signs
of slowly failing, and it is doubtful that PEM:: could be repaired if it failed.
The PEM system depends on PEM:: for instrument commanding and telemetry flow,
so it is an integral part of the PEM ground system.  Current tests of telemetry
transfers through PEM2K:: have been successful.

    Updated HEPS calibration parameters have been finalized and are ready for 
delivery.  Updated MEPS quality calibration files have been finalized and are 
ready for delivery.  Level 3 software errors, discovered by Dr. Dean Pesnell, 
have been fixed; his suggestions have been incorporated with in the PEM 
production code.  Both updated HEPS and MEPS calibration data, along with the 
Level 3 code changes, will influence the in-situ energy deposition predictions,
so new versions of PEM energy deposition Level 3 files will be generated.

*Beginning of power orbit day (PEM activation): array current >5 amps, array 
     voltage >53.5 volts, and battery current >2.0 amps.  
 End of power orbit day (PEM deactivation): time in power orbit day >4 minutes,
     array current <9 amps, and battery currents <0.2 amps.
 Power orbit day variation: ~39-40 min at yaw to ~50-51 min at maximum beta.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Daily processing of instrument Daily Activity Plans continues 
with no problems.  The MPG continues to coordinate with the 
Flight Operations Team and to assist the Project Scientist 
with the scheduling of instrument operations.  The published
instrument operations schedule is complete to 3 January 2001. 
 
***********
CDHF
***********

DAAC DATA:
   -  Data received and cataloged at the CDHF in the month of Sept., 2000 for
      HALOE, NMC, and UKMO has been previewed in preparation for DAAC Transfer.

UARS CDHF REHOST:
   -  PI validation of output products and concerns are being addressed.
      SUSIM reason for differences is being confirmed with COMPAQ.
   -  System performance criteria is being confirmed.

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

                           REPORTING PERIOD

This report covers 04 November 2000 (Orbit 50011, GMT Day 309) through 
10 November 2000 (Orbit 50115, GMT Day 315).

                       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          310/0359   50028     Power ON - FULLTIME 
 SUSIM        313/1715   50081     Halted
 PEM          314/2226   50100     ZEPS & NEPS to day only
 PEM          315/0200   50102     DAY OPS ONLY
 WINDII       315/0416   50103     Power ON
 WINDII       315/0837   50106     Power OFF
 WINDII       315/1719   50111     Power ON
 WINDII       315/1804   50112     Power OFF

The beta angle ranged between the angles of 52.7 degrees to 76.1 degrees 
for this report period.  The beta angle is now decreasing towards a 
minimum angle of 2 degrees on 3 December 2000 (DOY 337).

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 0.0 degrees C.  Additional battery 
performance data for each battery on 3 November 2000 and 10 November 
2000 are provided in Appendix D.

The clock error ranged from -8.6 to 12.1 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.

¥     OUT-OF-LIMITS  =  04
¥     ALERTS         =  02

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


¥     FOT            =  14
¥     SUSIM          =  01
¥     PEM            =  03
¥     WINDII         =  04

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

¥     FOT            =  07

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

TRANSPONDER FREQUENCIES:
· Transponder A:  00/221  -  2287.496937
· Transponder B:  00/305  - 2287.499087



                      GROUND SYSTEM OPERATION

Seven (7) 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 00/314 show the observatory data loss to 
be 299 hours, 20 minutes, 15.664 seconds (an increase of 34 minutes and 
49.200 seconds since the last report period).  This is a 0.39 percent 
data loss which equals a 99.61 percent data capture for the mission.

The increase of 34 minutes and 49.200 seconds occurred over three (3) 
days:

· 32 minutes 14.976 seconds on Day 309 due to an ATC halt on S/C
· 0 minutes 13.504 seconds on Day 312 due to a data hit.
· 2 minutes 20.720 seconds on Day 314 due to a Forward Reacquisition

                    OTHER SIGNIFICANT EVENTS

                    UARS SATELLITE OPERATIONS

On 06 November 2000 a +10 degree yaw offset maneuver was performed.  
This was done as a preliminary test for the +10 degree yaw offset, which 
will be performed on 07 November 2000 over the course of the high beta 
incident this as well as part of next week.  The yaw offset is necessary 
to bring the sun back into the field of view of the Fine Sun Sensor 
(FSS).

Testing continues daily to get the TAM and FSS attitude control solution 
operational.  The UARS testing and training simulator (UTTS) is being 
used for all testing.  In order to insure the validity of the test the 
FOT has been debugging some problems with the simulator attitude models.  

                            MEETINGS

No meetings were attending by the FOT during the course of this week.


                   FUTURE SIGNIFICANT EVENTS

The next UARS Yaw slew is scheduled for December 02, 2000 (DOY 337).  
This maneuver will be a Reverse to Forward Flight maneuver (Northern 
Hemisphere viewing).

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 10 November 2000

ORBIT     AOS        NO.      SUBSYS     REASON
-----     ---        ---      ------     ------
50012     309/0211   00-616   NBTR       PLAYBACK
50014     309/0511   00-616   NBTR       NOOPS D-309
50026     309/2356   00-619   ATC        LOCATION JUMP
50026     310/0032   00-618   NBTR       PLAYBACK
50028     310/0359   00-620   PEM        Power ON - FULLTIME 
50029     310/0513   00-621   OBC        Clk Adj 0.00 to 20.6 msec/day
50034     310/1348   00-618   NBTR       PLAYBACK
50045     311/0733   00-622   NBTR       PLAYBACK
50049     311/1345   00-623   ACS        YAW S/C 10 deg.
50051     311/1623   00-624   ACS        YAW S/C back to 0 deg.
50053     311/2035   00-625   ACS        UFLTR FSS to monitor mode
50064     312/1348   00-626   ACS        YAW S/C 10 deg.
50073     313/0338   00-627   OBC        Clk Adj 20.6 to 41.2 msec/day
50075     313/0736   00-628   NBTR       PLAYBACK
50076     313/0833   00-629   NBTR       RECORD STOP - HI TEMP
50081     313/1715   00-630   SUSIM      Halted
50100     314/2226   00-631   PEM        ZEPS & NEPS to day only
50102     315/0200   00-632   PEM        DAY OPS ONLY
50103     315/0416   00-633   WINDII     Power ON
50106     315/0837   00-634   WINDII     Power OFF
50111     315/1719   00-633   WINDII     Power ON
50112     315/1804   00-635   WINDII     Power OFF
________________________________________________________________________
_

                            APPENDIX B
              OUT-OF-LIMITS & ALERTS OCCURRENCES
                 Week ending 10 November 2000

The following Out-Of-Limits occurrences were detected:

MNEMONIC       STATE    DESCRIPTION                 ORBITS
--------       -----    -----------                 ------
QTZEPIF1       Y-LO     ZEPS INTERFACE TEMP 1       50073-6     
NBTUTEMP2      Y-LO     NBTR 2 TEMP                 50074-6     
NBTUTEMP2      R-LO     NBTR 2 TEMP                 50076,83-85     
CDRIUABINTRT   Y-LO     RIU 1 Internal temperature  50093-50100


The following ALERT occurrences were detected:

MNEMONIC        DESCRIPTION                        ORBITS
--------        -----------                        ------
SSSWLIMFAIL     SSPP AT SOFTWARE STOP              50015                    
HGSWLIMFAIL     High Gain software limit reached   50051     

________________________________________________________________________

                           APPENDIX C
              CLOCK & SOLAR ARRAY RATE CORRECTIONS
                 Week ending 10 November 2000

                  CLOCK DRIFT RATE ADJUSTMENTS

ORBIT     TIME         CLOCK RATE CHANGE
-----     -------      ---------------------------------
50029     310/0522     Clk Adj from 0.00 to 20.6 msec/day
50073     313/0341     Clk Adj from 20.6 to 41.2 msec/day
________________________________________________________________________
_

                           APPENDIX D
                 UARS BATTERY PERFORMANCE DATA
                  Week ending 10 November 2000


     03 Nov 2000 - GMT Day 308 Beta = 48.9 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    14.2    0.000     0.0
2    +22.4/-22.4    +5.15/+3.87  +26.4/-15.2  25.1    1.030     20.5
3    05.6/-44.8     +4.51/+2.60  +25.6/-15.2  25.1    1.020     20.0


     10 Nov 2000 - GMT Day 315 Beta = 76.1 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  -2.73/-3.05  +0.0/+0.0     14.2    0.000     0.0
2    +11.2/0.0      +2.60/+2.60  +15.6/+9.6    31.7    1.040     13.6
3    0.0/-28.0      +1.97/+1.97  +09.6/+9.2    31.7    1.040     13.1


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

                           APPENDIX E
                       UARS ANOMALY REPORTS
                    Week ending 10 November 2000

NEW ANOMALY REPORTS GENERATED
AR NO.     SUBSYS  ORBIT     TIME       TTR     PROBLEM/DATA LOSS
------     ------  -----     ----       ---     -----------------
00-048     FOT     50025     309/2255   N/A     ATC HALT
00-047     FOT     50037     310/1853   14170   Generic Late Acquisition
00-049     FOT     50051     311/1623   N/A     HGA at S/W stop limit
00-047     FOT     50081     313/1715   14170   Generic Late Acquisition
00-047     FOT     50088     314/0414   14170   Generic Late Acquisition
00-047     FOT     50089     314/0657   14170   Generic Late Acquisition
00-047     FOT     50108     315/1209   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
AR NO.     SUBSYS     ORBIT     TIME     TTR     PROBLEM/DATA LOSS
------     ------     -----     ----     ---     -----------------
           -None this report period

                     OPEN ANOMALY REPORTS
AR NO.     SUBSYS    ORBIT     TIME      TTR     PROBLEM/DATA LOSS
------     ------    -----     ----      ---     -----------------
00-047     FOT       see list  Nov 00    14170   Generic Late 
Acquisition
00-048     FOT       50025     309/2255  N/A     ATC HALT
00-049     FOT       50051     311/1623  N/A     HGA at S/W stop limit



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