UARS Weekly Status Report

05 May 2000




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                UARS WEEKLY STATUS REPORT - 05 MAY 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.

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

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

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

Nothing received.

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

Nothing received.

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

HALOE continues successful operations with all engineering parameters
within nominal operating region.  HALOE will be powered off some time May
7th as the spacecraft enters the graze period.

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

Nothing received.

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

Nothing received.

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WINDII
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Nothing received.

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

The MPG participated in the Monthly Status Review  Meeting, held on 3
May. The MPG distributed the Instrument Operations Schedule for the next
yaw period: 4 June to 4 July 2000.

All the systems in the MPG room were shutdown  on May  4 for the power
reconfiguration operation. All the systems are operational after reboot.
Routine processing of instrument Daily Activity Plans continues with no
problems.


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CDHF
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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

The CDHF will be sending out an updated version of the NASA Security
Rules of Behavior to all users, in accordance with NASA ISO requirements.

UARS CDHF REHOST:
   -  Successful processing on Rehost System:
       Attitude Extraction, Observatory Log, Sensor Extraction, HALOE, MLS,
       SUSIM, Solstice, and WINDII.
   -  An electronic ingest of LEVEL0, UARS DAY ,3144,3155,3156,3157,3158 was
      received from the LZP. Validation in progress.
      Sensor Extraction Software was processed for 3144.  FDF has performed
      a successful quality check against the Sensor Files.
   -  Test HRDI V4.4 on the Rehost System.                    
   -  Preparing to test ISAMS V12.0 and PEM V3.32 software on the
      Rehost System.
   -  Preparing to test DAAC transfer software.
                  
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FOT
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                           REPORTING PERIOD

This report covers 22 April, 2000 (Orbit 47073, GMT Day 113) through 28 April 
2000 (Orbit 47177, GMT Day 119).


                        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
     HALOE        113/0408     47075     Off
     HALOE        119/1152     47170     On
     HALOE        119/2130     47176     Off
     HALOE        119/2130     47176     On

A Reverse-to-Forward Yaw Around maneuver (number 88) was successfully executed 
in Orbit 47127 beginning 116/15:52:58 and completing at 116/15:30:08 on 25 
April 2000.  The SSPP Instruments (ACRIM, SOLSTICE, SUSIM) were enabled as well 
as HRDI and PEM in day only operations.  Due to the SA position at 269 degrees, 
the effective night length of the spacecraft after the maneuver was 
approximately 51 minutes.  Post maneuver analysis of data indicate that during 
the Yaw Around, the end-of-night load bus voltage was 23.5 volts and the 
average depths of discharge (DODs) on Batteries 2 and 3 were approximately 22.0 
and 22.5 percent respectively.  The next (forward-to-reverse) YAW is scheduled 
for 05 June 2000 (DOY 157).

The beta angle ranged between the angles of 17.7 degrees to 12.5 degrees for 
this report period.  The beta angle is now increasing toward a maximum angle of 
+76.0 degrees on 15 May 2000 (DOY 136).

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 1.0 to 1.3 degrees C.  Additional battery performance data for each 
battery on 21 April 2000 and 28 April 2000 are provided in Appendix D.

The clock error ranged from 3.4 to -9.8 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  =  07
%     ALERTS         =  01

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

%     FOT            =  06
%     HALOE          =  05

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

%     FOT            =  03

Three (3) 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

Three (3) 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 00/118 show the observatory data loss to be 295 hours, 29 
minutes, 41.209 seconds (an increase of 23 minutes 12.064 seconds since the 
last report period).

The increase of 23 minutes 12.064 seconds occurred over one (1) day:

- 23 minutes 12.064 seconds on Day 116 due to POCC scheduling error.

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


                       OTHER SIGNIFICANT EVENTS

                       UARS SATELLITE OPERATIONS

The FOT continues to have problems properly loading the new TMONs to the 
simulator.  Both the FOT and its support staff are doing everything possible to 
identify and correct this problem so that the testing of the new safehold TMONs 
can begin.

The FOT continues to develop 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

In support of the UARS Upgrade task, the FOT attended a meeting to discuss the 
basic roles and activities of each FOT member.

The FOT held a meeting with NASA battery experts on 28 April 2000.  The goal of 
the meeting was to determine the proper offset angle for the solar array in the 
new online procedure for safehold. Identifying this angle will require more 
analysis and will hopefully be determined sometime next week.


                    FUTURE SIGNIFICANT EVENTS

The next UARS Yaw slew is scheduled for June 05, 2000 (DOY 157).  This maneuver 
will be a Forward to Reverse 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 28 April 2000

ORBIT     AOS        NO.       SUBSYS     REASON
-----     ---        ---       ------     -------
47074     113/0231   00-173    NBTR       NBTR PLAYBACK
47075     113/0408   00-174    HALOE      EARLY OFF- S/C LOW PWR
47075     113/0453   00-173    NBTR       NBTR OPS DAY 113
47089     114/0314   00-175    NBTR       NBTR PLAYBACK
47167     119/0749   00-176    NBTR       NBTR OPS DAY 119
47170     119/1152   00-177    HALOE      Power ON
47170     119/1249   00-178    OBC        Clk Adj 0.00 to -20.6 msec/day
47174     119/1806   00-179    NBTR       NBTR OPS DAY 120
47174     119/1837   00-180    HALOE      Power ON
47176     119/2130   00-181    HALOE      Power OFF
47176     119/2130   00-182    HALOE      Power ON

_______________________________________________________________________________
 
                           APPENDIX B
               OUT-OF-LIMITS & ALERTS OCCURRENCES
                    Week ending 28 April 2000

The following Out-Of-Limits occurrences were detected:

MNEMONIC        STATE     DESCRIPTION                   ORBITS
---------       -----     ------------                  ------
HRPSEQBIMON     Y-HI      PSE Quiet Bus Current Mon     47074
HRPSEQBIMON     Y-HI      PSE Quiet Bus Current Mon     47105-8
HRPTSPBIMON     R-LO      PTS Pulse Bus Current Mon     47117
HRPTSPBIMON     R-LO      PTS Pulse Bus Current Mon     47117-8
HRPSEQBIMON     Y-HI      PSE Quiet Bus Current Mon     47120-22
OBSVLBEON       Y-LO      Load Bus Volts at EON         47129
HRPTSPBIMON     R-LO      PTS Pulse Bus Current Mon     47135-8

The following ALERT occurrences were detected:

MNEMONIC       DESCRIPTION                              ORBITS
---------      ------------                             ------
OBSZ1OOL       UFLTR Z1 Residual Exceeded 100 Arcsec    47127


   
                              APPENDIX C
                CLOCK & SOLAR ARRAY RATE CORRECTIONS
                      Week ending 28 April 2000

                    CLOCK DRIFT RATE ADJUSTMENTS

ORBIT     TIME                      CLOCK RATE CHANGE
-----     ----                      -----------------
47170     119/12:51 (28 Apr 00)     from 0.00 to -20.6 msec/day

_______________________________________________________________________________

                              APPENDIX D
                     UARS BATTERY PERFORMANCE DATA
                      Week ending 28 April 2000


     21 April 2000 - GMT Day 112 Beta = 17.7 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     -22.4/-44.8   -3.05/-4.31  +0.0/+0.0     15.8    0.000     0.0
2     +84.0/-5.6    +6.44/+5.15  +30.4/-14.4   24.0    1.030     22.5
3     +33.6/-44.8   +5.15/+3.87  +29.6/-15.2   23.8    1.030     22.0


     28 April 2000 - GMT Day 119 Beta = 12.5 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    -22.4/-44.8    -3.68/-4.94  +0.0/+0.0     15.8     0.000     0.0
2    +33.6/-11.2    +5.47/+3.87  +30.4/-14.4   24.3     1.022     20.5
3    +33.6/-5.6     +4.51/+2.60  +29.6/-15.2   24.2     1.020     20.1


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

                            APPENDIX E
                       UARS ANOMALY REPORTS
                     Week ending 28 April 2000

                   NEW ANOMALY REPORTS GENERATED
AR NO.     SUBSYS    ORBIT     TIME        TTR     PROBLEM/DATA LOSS
------     ------    -----     ----        ---     -----------------
00-016     FOT       47130     116/2012    22279   HGA slew error
00-018     FOT       47165     119/0415Z   N/A     AP-8 Crashed
00-019     FOT       47166     119/0635    N/A     AP-8 Crashed

                   ANOMALY CLOSURE INFORMATION RECEIVED
AR NO.     SUBSYS    ORBIT     TIME        TTR     PROBLEM/DATA LOSS
------     ------    -----     ----        ---     -----------------
00-016     FOT       47130     116/2012    2227    HGA slew error
00-018     FOT       47165     119/0415Z   N/A     AP-8 Crashed
00-019     FOT       47166     119/0635    N/A     AP-8 Crashed

                 ANOMALY INVESTIGATION REPORTS GENERATED
AR NO.     SUBSYS    ORBIT     TIME        TTR     PROBLEM/DATA LOSS
------     ------    -----     ----        ---     -----------------
00-002     FOT       47130     116/2012    22279   HGA slew error

                        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.

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