UARS Weekly Status Report

14 April 2000




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                UARS WEEKLY STATUS REPORT - 14 APR 2000

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

We continue to gather enough data to meet all the SOLSTICE science
objectives during this period of reduced tape recorder operations.
SOLSTICE operates normally, collecting solar data on all available
orbital tracking periods and stellar calibration observations whenever
possible. Level 2 processing is halted due to bugs in the OA_SSPP_ATT
service. CDHF and CSC personnel are working on the problem.

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

SUSIM continues to gather a near normal set of daily solar scans
scheduled for periods of predicted telemetry.

Last week, this report mentioned that SUSIM did not take data on
UARS day 93.  This date was incorrect.  It should have read
"UARS day 97", instead.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

Nothing received.

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

 The HRDI instrument is operating normally, collecting data on every
daytime portion of an orbit.

The HRDI operations team is completing an upgrade of the flight modes
which compensates for some of the mechanical aging by operating the
instrument in a more closed loop fashion, i.e. instrument timing is based
on actual positions of various components (telescope position, filter wheel
position) rather than conservative timing estimates.

Work proceeds on a new data delivery, which will allow the data to be
processed properly with the frequent dropouts.  In addition, algorithm 
refinements and a new product, mesospheric ozone, are being added.

***********
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 Scientistwith the scheduling 
of instrument operations. 

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

STATUS                       
   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.
   - All requested reprocessing is complete as of this reporting period.

UARS CDHF REHOST:
   -  Successful processing on Rehost System:
      Attitude Extraction, Observatory Log, Sensor Extraction, HALOE, MLS,
      SUSIM, Solstice, and WINDII.
   -  MLS V4.22 (OUTPUT 4) has tested successfully on Rehost System.  MLS
      has validated the output product. Thanks for the timely response.         
   -  Preparing to test ISAMS V12.0 and PEM V3.32 software on the
      Rehost System.
                  
***********
FOT
***********


                              REPORTING PERIOD

This report covers 01 April, 2000 (Orbit 46759, GMT Day 092) through 07 April 
2000 (Orbit 46862, GMT Day 098).


                            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            096/2255     46832     AXIS Off
        WINDII         097/0036     46833     On

The beta angle ranged between the angles of 38.1 degrees to 49.2 degrees for 
this report period.  The beta angle is now increasing toward a maximum angle of 
+49.0 degrees on 08 April 2000 (DOY 099).

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 1.1 degrees C.  Additional battery performance data for each 
battery on 17 March 2000 and 07 April 2000 are provided in Appendix D.

The clock error ranged from 11.2 to -11.1 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  =  01
%     ALERTS         =  02

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

%     FOT            =  20
%     HRDI           =  04
%     PEM            =  01
%     WINDII         =  01

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

%     FOT            =  05

Five (5) Anomaly Reports remained OPEN at the end of this report period (see 
Appendix E).

TRANSPONDER FREQUENCIES:
- Transponder A:  00/091  -  2287.496948
- Transponder B:  00/091  -  2287.499113


                        GROUND SYSTEM OPERATION

Five (5) operational support problem 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 00/097 show the observatory data loss to be 301 hours, 12 
minutes, 33.513 seconds* (an increase of 0 minutes 0.00 seconds since the last 
report period).

*These calculations have been recalculated to include 1999/346 through 2000/006 
statistics using scheduled times.


                      OTHER SIGNIFICANT EVENTS

                      UARS SATELLITE OPERATIONS

The FOT corrected the halt of the ATCP (refer to AIR-001/00) on 03 April 00.  
The halt was caused by the CMS incorrectly reporting the uplink time for the 
new load.  Thus, the load was sent before it should have been, which overwrote 
the active ATC load.  The location overwritten was overwritten by and ATC halt 
command and that command went out.  This was not a case of operator error, 
however, because the CMS had reported a load after time of 17:53:11 GMT when it 
really wasn't safe to uplink the new load until after 18:01:13 GMT.  

In order to avoid this problem in the future the ATC uplink times will be 
checked manually to make sure they are valid.  A DR will also be written so 
that a fix to the CMS can be made that will perform this check automatically.

There were more problems encountered with the UTTS this week, but all have been 
fixed and the FOT is ready to begin testing of the new TMONs next week.

The FOT also began developing an online procedure for safehold should it happen 
before the new TMONs are in place or during and OBC halt.  This procedure has 
yet to be finalized and must undergo peer review before it will be ready.


                                MEETINGS

The FOT attended the UARS monthly status meeting 05 April 00.


                       FUTURE SIGNIFICANT EVENTS

The next UARS Yaw slew is scheduled for April 25, 2000 (DOY 116).  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 07 April 2000

 ORBIT     AOS         NO.       SUBSYS     REASON
 -----     ---         ---       ------     -------
 46760     092/0350    00-132    NBTR       NBTR OPS DAY-092
 46761     092/0506    00-132    NBTR       NBTR OPS DAY-092
 46769     092/1759    00-135    NBTR       NBTR OPS DAY-093
 46771     092/2207    00-136    OBC        Clk Adj 0.00 to 20.6 msec/day
 46776     093/0542    00-135    NBTR       NBTR OPS DAY-093
 46784     093/1757    00-137    NBTR       NBTR OPS DAY-094
 46799     094/1751    00-138    OBC        Clk Adj 0.00 to 20.6 msec/day
 46799     094/1751    00-139    NBTR       NBTR OPS
 46799     094/1751    00-140    HRDI       HRDI MICROLOAD
 46799     094/1851    00-141    OBC        ATC POINTER
 46799     094/1851    00-142    HGA        HGA SLEW
 46803     094/2356    00-143    HRDI       CHECK TABLE INTERPRETER
 46803     095/0203    00-143    HRDI       CHECK TABLE INTERPRETER
 46805     095/0401    00-139    NBTR       NBTR OPS
 46806     095/0513    00-139    NBTR       NBTR OPS
 46813     095/1713    00-144    HRDI       HRDI MICROLOAD
 46814     095/1854    00-145    NBTR       NBTR OPS
 46821     096/0553    00-145    NBTR       NBTR OPS DAY-096
 46830     096/2036    00-146    NBTR       NBTR OPS DAY-097
 46832     096/2255    00-147    AXIS-1     Power OFF
 46833     097/0036    00-148    WINDII     Power ON
 46833     097/0036    00-149    OBC        Clk Adj 0.00 to 20.6 msec/day
 46835     097/0410    00-145    NBTR       NBTR OPS DAY-097
 46841     097/1240    00-149    NBTR       NBTR OPS DAY-098
 46852     098/0658    00-149    NBTR       NBTR OPS DAY-098
 46859     098/1802    00-150    NBTR       NBTR OPS DAY-099

_______________________________________________________________________________


                               APPENDIX B
                     OUT-OF-LIMITS & ALERTS OCCURRENCES
                         Week ending 07 April 2000

The following Out-Of-Limits occurrences were detected:

  MNEMONIC      STATE     DESCRIPTION                  ORBITS
  ---------     -----     ------------                 ------
  HRPSEQBIMON   Y-HI      PSE QUIET BUS CURRENT MON    46806     

The following ALERT occurrences were detected:

  MNEMONIC                DESCRIPTION                  ORBITS
  ---------               ------------                 ------
  SSCMDERR                SSPP CMD ERROR               46797
  HGSWLIMFAIL             HGA SW LIMIT ERROR           46799

_______________________________________________________________________________

                               APPENDIX C
                  CLOCK & SOLAR ARRAY RATE CORRECTIONS
                       Week ending 07 April 2000

                      CLOCK DRIFT RATE ADJUSTMENTS

  ORBIT     TIME                      CLOCK RATE CHANGE
  -----     ----                      -----------------
46771       092/22:13 (01 Apr 00)     from 0.00 to 20.6 msec/day
46799       094/17:53 (03 Apr 00)     from 20.6 to 0.00 msec/day
46833       097/00:56 (06 Apr 00)     from 0.00 to 20.6 msec/day

_______________________________________________________________________________

                               APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                        Week ending 07 April 2000


      DIFF V (mV)   TEMP (C)    CURR (amp)    EON V    AVE C/D   AVE
BAT   MAX/MIN       MAX/MIN     MAX/MIN       MIN      RATIO     DOD(%)
---  ------------   ----------  -----------   -------  -------   ------
      Battery performance data not available for this report period.


     07 April 2000 - GMT Day 098 Beta = 49.2 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    -33.6/-56.0   -3.05/-4.31  +0.0/+0.0     15.8     0.000     0.0
2    +56.0/-5.6    +5.47/+4.19  +26.4/-16.0   24.6     1.042     21.3
3    +22.4/-22.4   +4.51/+3.23  +26.0/-16.0   24.5     1.040     21.0

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


                                APPENDIX E
                           UARS ANOMALY REPORTS
                          Week ending 07 April 2000

                         NEW ANOMALY REPORTS GENERATED
 AR NO.     SUBSYS    ORBIT     TIME       TTR       PROBLEM/DATA LOSS
 ------     ------    -----     ----       ---       -----------------
 00-008     FOT       46799    094/1751              ATC Halt
 00-005     FOT       46799    094/1851    14170     Generic Late Acq.
 00-009     FOT       46813    095/1713              No File Xfer Cap.
 00-010     FOT       46827    096/1428              No File Xfer Cap.
 00-007     FOT       46845    097/2038    14170     Generic Late Acq.

                  ANOMALY CLOSURE INFORMATION RECEIVED
 AR NO.     SUBSYS    ORBIT     TIME       TTR       PROBLEM/DATA LOSS
 ------     ------    -----     ----       ---       -----------------
 00-005     FOT      see list   March 00   14170     Generic Late Acq.
 00-008     FOT       46799     094/1751             ATC Halt

                  ANOMALY INVESTIGATION REPORTS GENERATED
 AR NO.     SUBSYS    ORBIT     TIME      TTR       PROBLEM/DATA LOSS
 ------     ------    -----     ----      ---       -----------------
 00-008     FOT       46799    094/1751             ATC Halt

                         OPEN ANOMALY REPORTS
 AR NO.     SUBSYS    ORBIT     TIME       TTR       PROBLEM/DATA LOSS
 ------     ------    -----     ----       ---       -----------------
 99-064     FOT       44135    10/8-9/99   N/A       HRDI Cal Lamp Errors
 99-071     FOT       44398    299/1212    21512     TPF Not Receiv 512
 00-007     FOT     see list   April 00    14170     Generic Late Acq.
 00-009     FOT       46813    095/1713              No File Xfer Cap.
 00-010     FOT       46827    096/1428              No File Xfer Cap.

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