UARS Weekly Status Report

3 April 1998





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                UARS WEEKLY STATUS REPORT - 03 APRIL 1998

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Note from Skip:

I'd like to thank everyone associated with UARS for all the thoughts, 
calls, cards, flowers, and the HUGE card signed by the Science Team at 
the meeting in Pasadena.   I returned to work yesterday part time and 
I'm getting better every day. The doctors say I'll be back to normal 
shortly (as soon as they can figure out what "normal" is in my case.)


...........Skip Reber
 

***********
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
***********

SUSIM successfully gathered its normal solar, offset, and occultation
scan data this week without apparent problems.

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

     PEM is currently off.

     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 
***********

Nothing received.

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

MLS was reactivated successfully on Mar 26, in the reduced 85 watt power
mode. MLS instrument operations have continued flawlessly.  MLS was powered
off at 089:01:38 UT.  MLS is scheduled to begin north viewing operations
starting Apr 15.

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

HRDI is in low-power standby mode.

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

WINDII is awaiting activation on April 4, running through April 7.

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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
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All level 0 data for power outage days were received by 27-March-1998.
All current day production processing is up to date.

The CDHF has received a total of 381 CD-ROM requests as of 3-April-1998.
There was one order received and shipped.
 
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-1074C=305L)
                  84 days MLS (4.90) PROD (1297R-1223C-17F=57L)
                   5 days CLAES (7.0) ENG (38R-37C=1L)
                   1 days HAL (4.80) ENG  (5R-5C=0L)

The CDHF attended a meeting with various contractors, tele-com to MSFC
and AMES, regarding NISN support of the UARS network. The CDHF provided
attendees original and current network requirements, copies of two MOUs, NSI
presentations, and a Network Topics list.
              
UKMO data for UARS Day 2263 and 2264 have been requested but not yet received.
Only remaining UKMO day not received from last weeks outage is 2390. 

The CDHF will load February 1998 current day DAAC data in April 1998.
 
Pending CDHF software upgrades: IDL 5.0, OpenIngres, UCSS.

                  
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FOT
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REPORTING PERIOD

This report covers 20 March 1998 (Orbit 35644, GMT Day 079) through 27 
March 1998 (Orbit 35644, GMT Day 086).


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
            WINDII       080/2333     35659     Off
             HALOE       084/2232     35719     Off
              MLS        085/0020     35720     On
             HRDI        086/2348     35749     Off

The beta angle is now increasing toward a minimum angle of 0.0 degrees on 
02 April 1998 (DOY 092).

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 1.4 degrees C.  Additional battery performance data for 
each battery on 21 March 1998 and 27 March 1998 are provided in Appendix D.

The clock error ranged from -10.5 to +9.4 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          =    none
%     OUT-OF-LIMITS   =    03

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

%     FOT       03
%     HALOE     01
%     HRDI      01
%     MLS       01
%     WINDII    01

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

%     FOT       01

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


TRANSPONDER FREQUENCIES:
     Transponder A:  98/041  -  2287.497104
     Transponder B:  98/042  -  2287.499330


GROUND SYSTEM OPERATION

One (1) 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 98/085 show the observatory data loss to be 
20 hours, 42 minutes, 33.140 seconds (an increase of 16.480 seconds).  This 
is a 0.0363 percent data loss which equals a 99.9637 percent data capture 
for the mission.

The increase of 16.480 seconds occurred over three days as follows:

  A 1.088 second loss on Day 079 due to a hit in the data,
 
  A 10.336 second loss on Day 080 due to insufficient overlap, and
 
  A 4.256 second loss on Day 081 due to hit in the data and on the 
transmission line.

Building 23 power was restored as scheduled on Monday, 23 March 1998.  No 
problems were observed. Operation during the GSFC Building 23 weekend power 
outage was nominal with all alternate operational methods successful.  
Replay of the telemetry data recorded at the TDRSS White Sands Ground 
Terminal was completed and level-0 files created by Friday, 27 March.

No IP testing was executed by the FOT this week.  The FOT will resume IP 
testing next week, particularly concentrating on Q-channel OBC dumps, and 
possible forward link testing.  A decision has still not been made by the 
UARS FOT and project whether or not to begin testing the IP forward link 
directly with the spacecraft (using NOOP commands), or to try to configure 
some kind of special test scenario using the UTTS.  A deadline for complete 
switch-over to the IP network has been set for mid July 1998.

The FOT began making modifications to the OBCSTF resident POCC database.  
These changes will be incorporated into the next operational database 
release, version 66.

Operational processing of level-0 telemetry analysis files has been 
suspended until the UMPGAL cluster and network interface configurations are 
finalized.



OTHER SIGNIFICANT EVENTS

Work on the upgrade of the OBC Power Monitor (PMON) software continued.  
Continued database work for new PMON software.  Worked to define new RTS 
and PDB assignments to support PEM day-only operation.  These new RTSs and 
PDBs will be included with the new PMON software uplink.

FOT continues to support CNMOS in their efforts to make necessary software 
changes (MSOCC, CMS, DCF, etc.) to support the year 2000 rollover.

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.


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 02 April 1998.

A second building 23 power outage is scheduled from about 12 pm, 24 April 
1998, until about 12 pm, 27 April 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 
is targeted for 05 August 1998.


PERSONNEL CHANGES

Craig Woodruff will no longer be the UARS prime point of 
contact in Flight Dynamics Facility (FDF), starting next week.  Craig's 
responsibilities will now be handled by Dan Andrews.


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 March 1998

ORBIT      AOS       NO.     SUBSYS        REASON
-----      ---       ---     ------        -------  
35659   080/2333   98-110     OBC       Clk Adj fr 20.6 to 0.00 msec/day
35659   080/2333   98-111     WINDII    Power OFF
35685   082/1633   98-112     OBC       Clk Adj fr 0.00 to 20.6 msec/DAY
35712   084/1154   98-113     OBC       Clk Adj fr 20.6 to 0.00 msec/day
35719   084/2232   98-114     HALOE     Power OFF
35720   085/0020   98-115     MLS       Power ON
35749   086/2348   98-116     HRDI      Low Power mode


_______________________________________________________________

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

MNEMONIC      STATE      DESCRIPTION                  ORBITS
---------     -----      ------------                 ------
WIEUTEMP     Y-LO     WINDII EU Temperature          35712-19
WIEUTEMP     Y-HI     WINDII EU Temperature          35721-24
HRPTSPBIMON  Y-HI     Tele Pulse Bus Cur Monitor     35741


The following ALERT occurrences were detected:

MNEMONIC                 DESCRIPTION                  ORBITS
---------               ------------                  ------
              None this report period
          



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

                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT              TIME                 CLOCK RATE CHANGE
     -----              ----                 -----------------
     35659     080/23:42 (21 Mar 98)     from 20.6 to 00.0 msec/day
     35685     082/16:38 (23 Mar 98)     from 00.0 to 20.6 msec/day
     35712     084/11:58 (25 Mar 98)     from 20.6 to 00.0 msec/day


_______________________________________________________________

                               APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                      Week ending 27 March 1998

     21 Mar 1998 - GMT Day 080 Beta = 43.6 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    18.4    0.000     0.0
2   +33.6/ -22.4   +6.44/+4.83  +28.8/-16.4    25.0    1.023    22.4
3  +100.8/  +0.0   +5.15/+3.87  +28.0/-16.4    24.8    1.025    21.8

     27 Mar 1998 - GMT Day 086 Beta = 22.7 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  +728.0/+728.0  -3.05/-3.99   +0.0/ +0.0     18.4    0.000     0.0
2   +78.4/  -5.6  +7.74/+5.79  +32.0/-16.0     24.0    1.019    24.0
3   +78.4/  +0.0  +6.11/+4.51  +31.2/-16.8     23.8    1.021    23.3


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



                               APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 27 March 1998

  AR NO.   SUBSYS  ORBIT      TIME      TTR    PROBLEM/DATA LOSS
  ------   ------  -----      ----      ---    -----------------
98-009   FOT     35631    080/0250   14171   Generic Late Acquisition


                     ANOMALY CLOSURE INFORMATION RECEIVED
  AR NO.   SUBSYS  ORBIT      TIME      TTR    PROBLEM/DATA LOSS
  ------   ------  -----      ----       ---      -----------------
98-012   FOT     35595    076/16:22  19757   Late Acq FOT Conf
98-013   FOT     35603    077/06:06            Tac 4 Crash



                    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
  ------   ------  -----      ----      ---    -----------------
98-009    Generic Late Acq for March 1998. Open until 31 March 1998.

	 	SEVNTFW13