UARS Weekly Status Report

08 May 1998





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

                UARS WEEKLY STATUS REPORT - 8 MAY 1998

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

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

SOLSTICE continues to operate normally, collecting solar data on all 
available orbital tracking periods and stellar calibration observations, 
whenever possible.  

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

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

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

     PEM is not active.

GSFC has proposed an OBC operation plan for the activation of PEM boom 
instruments during the daylight portions of every orbit.  This OBC operation 
plan is under evaluation by PEM.

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

Nothing received.

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

MLS was reactivated successfully on Apr 29, in the reduced 85 watt power
mode. MLS instrument operations have continued flawlessly.  MLS was powered
off May 2 at 23:32 UT.  MLS is scheduled to begin south viewing operations
starting May 20.

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

Nothing received.

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

Nothing received.

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

Routine processing of instrument Daily Activity Plans continues 
with no other problems.  The MPG continues to assist the Project 
Scientist with the scheduling of instrument operations.

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

The CDHF receieved Level 0 for UARS days 2417, 2418, 2419 and 2420 on 05/03 and
05/04.  These days were delayed due to the building power outage on 04/24
through 04/27.
 
The CDHF has received a total of 386 CD-ROM requests as of 08-May-1998.
No new orders were received.
   
The CDHF receieved UKMO Day 2263 and 2264.
                                    
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.           
                  43 days PEM (3.32) PROD (1379R-1212C=167L)
                   2 days HAL (4.80) PROD (Test) (2R-2C=0L)
                   1 days WIN (5.1) ENG (1R-1C=0L)

CDHF worked on proposed UARS CDHF system configuration changes and
associated improvements and impacts.     

***********
NOAA DATA
***********

NOTICE OF CHANGE IN TEMPERATURES FROM NCEP ANALYSES

On May 1, 1998 NCEP operational stratospheric analyses began using RTOVS
(Revised TIROS Operational Vertical Soundings) from the NOAA-14 satellite.
TOVS data had been produced by NESDIS (National Environmental Satellite Data
and Information Service) from the operational NOAA series of satellites for the
last two decades.  RTOVS was introduced as a transition to ATOVS (Advanced
TOVS), in preparation for the launch of NOAA-K later this month (May 13, 1998).
Once operational, NOAA-K becomes NOAA-15.  TOVS and RTOVS soundings use data 
from the Stratospheric Sounding Unit (SSU), the Microwave Sounding Unit (MSU),
and the High resolution InfraRed Sounder (HIRS).  ATOVS will derive soundings
from the HIRS and the Advanced Microwave Sounding Unit (AMSU).  Comparisons to
radiosonde data show general improvement with RTOVS data.  Average RTOVS/TOVS
differences at the various pressure levels change in magnitude and sign with
season and latitude, but in general are less than 1 K degree.  In some
instances, differences of up to 3 K apparent.

For more information, contact Mel Gelman at melvyn.gelman@noaa.gov or
at 301-763-8000 x7558.
                  
***********
FOT
***********

REPORTING PERIOD

This report covers 24 April 1998 (Orbit 36169, GMT Day 115) through 01 May 
1998 (Orbit 36272, GMT Day 121).


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
       HRDI          115/0205       36170       On
       HALOE         118/2304       36228       Off
       MLS           119/0039       36229       On
       HRDI          120/1115       36250       Off

A summary of Instrument operations supplied by the Mission Planning Group 
for the month of April 1998 is contained in Appendix F, UARS Instrument 
Operations Summary.

The beta angle is now decreasing toward a minimum angle of 0.0 degrees on 
05 May 1998 (DOY 125).

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 24.2 V end-of-night (EON) load bus voltage.  
Battery temperatures are stable with a temperature delta between Battery 2 
and Battery 3 of 1.2 degrees C.  Additional battery performance data for 
each battery on 25 April 1998 and 01 May 1998 are provided in Appendix D.


The clock error ranged from -10.9 to +11.8 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.

%     ALERTS            =     none
%     OUT-OF-LIMITS     =     08

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    02
%     MLS     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: 98/062 -  2287.496945
     Transponder B: 98/062 -  2287.497010


GROUND SYSTEM OPERATION

No (0) operational support problem(s) 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 98/120 show the observatory data loss to be 
20 hours, 43 minutes, 08.788 seconds (an increase of 14.624 seconds since 
last report period).  This is a 0.0358 percent data loss which equals a 
99.9642 percent data capture for the mission.

The increase of 14.624 seconds occurred over a three day period:

7 9.888 seconds on Day 115 due to hits in the data,
7 0.448 seconds on Day 116 due to hits in the data, and
7 4.288 seconds on Day 117 due to hits in the data.

The FOT EXPERIENCED along-track ephemeris transition comparisons in excess 
of 1.5 km when processing the ephemeris in the Command Management System 
(CMS) software this week. The out-of-limit comparisons occurred on two of 
the three ephemeris delivery days.  The FOT will contact FDF next week to 
discuss the status of their investigation into the need for more frequent 
spacecraft ephemeris deliveries.

The FOT performed a limited amount of IP testing this week.  As with 
previous testing, the FOT ran a spare AP in a parallel environment to 
monitor I-channel return telemetry.  The FOT also attempted to monitor Q-
channel OBC dumps via the IP system, but was unsuccessful.  On one event, 
the TAC crashed before the Q-channel dump was started.  On a second event, 
the TAC locked on the Q-channel data, but the dump compare was never 
conducted on the AP.  This was probably due to an operational or AP 
configuration problem by the FOT.  Investigation is underway as to what the 
FOT must due to achieve a successful Q-channel OBC dump.  Further testing 
is planned for next week

The FOT continued making modifications to the OBCSTF resident POCC database 
this week.  The number of additions, deletions, and modifications has 
turned out to be far more extensive than originally thought.  In addition, 
the FOT has been having intermittent problems with the OBCSTF terminal 
Rlocking upS during database entry.  The majority of the database 
modifications have been completed, but many hours worth of work still 
remain.  The database work is expected to be completed by 06 May 1998.

The FOT made a few modifications to the new CMS versions of Relative Time 
Sequences (RTSs) 39 and 40 this week.  The changes were necessary to 
preclude the need for frequent RTS reloading to properly control the 
SOLSTICE instrument.  The modifications were coordinated the SOLSTICE 
operations team.

The FOT received requests from SOLSTICE operations to perform two manually 
generated SSPP Stellar Offset experiments on GMT days 125 and 127.

The second Building 23 power outage began on schedule at noon on 24 April 
1998 and continued without event until 27 April 1998.  All data has been 
recovered from White Sands Ground Terminal.

Four days of level-0 data is missing (24 April to 27 April) on the CDHF 
system due to the weekend power outage at the close of this report period. 
RDummyS telemetry files were created for the missing days to allow daily 
UGPL products to run during the week.  The missing days are planned to be 
processed over the weekend of 02-03 May, and the RdummyS files will be 
replaced with actual data the following Monday (04 May).  Post-status note: 
All missing level-0 data was processed by about noon today (04 May), and 
UGPL products have been restored to nominal operation.  All data is 
included in the data quality statistics at the beginning of this section.


OTHER SIGNIFICANT EVENTS

Work on the upgrade of the OBC Power Monitor (PMON) continued. FOT 
coordinated with PEM, MLS, and SOLSTICE for inputs to new PMON software 
(these instruments primarily affected by changes) this week.  New 
operations scenarios for each of these instruments, including new ground 
database commands, telemetry, and RTS/PDB definitions were generated.

Work continues on the UARS August orbit adjust planning.

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.  
A response to a list of questions was prepared for distribution this week.


MEETINGS

No UARS Battery telecon was held this week.  The next telecon has not been 
scheduled.

A follow-up meeting to discuss and confirm the changes made to the OBC 
Ground Image to support the OBC Flight Software update was held on 30 April 
1998.  A decision was reached to proceed with the development/release of 
Version 10.11 of the Application Processor software to support the OBC PMON 
update.  An operational pack will be available by the end of May 1998.  FOT 
will conduct testing of the software and data base changes using the 10.11 
version test pack while the official release process and operational pack 
generation takes place.


FUTURE SIGNIFICANT EVENTS

The next UARS Yaw Around Maneuver is currently scheduled for 05 May 1998.

The UARS orbit altitude is dropping slowly and a drag makeup orbit adjust 
is targeted for 05 August 1998.


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 F,  UARS Instrument Operations Summary




                               APPENDIX A
                       REAL-TIME COMMAND SHEETS
                      Week ending 01 May 1998

ORBIT      AOS           NO.     SUBSYS       REASON
-----      ---           ---     ------      -------  
36170     115/0205     98-149     HRDI     Power ON
36180     115/1736     98-150     OBC      Clk Adj fr 0.00 to 20.6 msec/day
36209     117/1636     98-151     OBC      Clk Adj fr 20.6 to 0.00 msec/day
36228     118/2304     98-152     HALOE    Power OFF
36229     119/0039     98-153     MLS      Power ON
36250     120/1115     98-154     HRDI     HRDI to low power
36272     121/2136     98-155     OBC      Clk Adj fr 0.00 to 20.6 msec/day



_______________________________________________________________

                               APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 01 May 1998

MNEMONIC       STATE      DESCRIPTION                       ORBITS
---------      -----      ------------                      ------
HRPTSPBIMON   Y-HI    PTS Pulse Bus Current Monitor  36171,235,39
QTSISAI/F     Y-HI    SSPP Baseplate by SISA I/F     36176,89,203,204,
                                                     267-72
WIEUTEMP      Y-LO     WINDII EU Temperature         36220,22,26,27,29-35
NBRECBI       Y-HI     NBTR B Total Current          36224,39
HRPSEQBIMON   Y-HI     PSE Quiet Bus Current Monitor 36224,39,49,69,70
CDUNRG28      Y-LO     +28V Unregulated Bus          36249
HRIFESURVTMP  Y-HI     IFE Survival Heater Temp      36253
HRRADTEMP     Y-HI     IFE Radiator Temperature      36253


The following ALERT occurrences were detected:

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



                               APPENDIX C
                 CLOCK & SOLAR ARRAY RATE CORRECTIONS
                      Week ending 01 May 1998

                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT              TIME                 CLOCK RATE CHANGE
     -----              ----                 -----------------
     36180     115/17:42 (25 Apr 98)     from 00.0 to 20.6 msec/day
     36209     117/16:50 (27 Apr 98)     from 20.6 to 00.0 msec/day
     36272     121/21:46 (01 May 98)     from 00.0 to 20.6 msec/day


_______________________________________________________________

                               APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                      Week ending 01 May 1998

     25 Apr 1998 - GMT Day 115 Beta = 36.9 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/-4.31  +0.0/ +0.0   18.4     0.000      0.0
2    +56.0/ -11.2  +6.44/+4.51 +29.6/-16.0   25.0     1.022     22.4
3   +123.0/  +0.0  +5.15/+3.23 +28.8/-16.0   24.8     1.024     21.9

     01 May 1998 - GMT Day 121 Beta = 17.3 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/-3.99   +0.0/ +0.0   18.4     0.000      0.0
2   +39.2/  -5.6  +7.09/+5.47  +32.0/-15.6   24.2     1.019     23.8
3   +44.8/  -5.6  +5.79/+4.51  +30.4/-16.0   24.2     1.021     23.0


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



                               APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 01 May 1998


                          NEW ANOMALY REPORTS GENERATED
  AR NO.   SUBSYS       ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------       -----      ----       ---      -----------------
98-022     FOT         36272    121/2136     N/A     TAC #2 Crashed


                       ANOMALY CLOSURE INFORMATION RECEIVED
  AR NO.   SUBSYS       ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------       -----      ----       ---      -----------------
98-015     FOT        April 1998            14170     GENERIC LATE ACQ


                     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
  ------   ------       -----      ----       ---      -----------------
98-021    Generic Late Acq for May 1998 (Open until 31 May 1998).




_______________________________________________________________
                               APPENDIX F
                   UARS INSTRUMENT OPERATIONS SUMMARY
                      Week ending 01 May 1998


              INSTRUMENT SUMMARY FOR MONTH OF April 1998 (hours)


                                    UNPLANNED      UNSCHEDULED
                 ON        OFF         OFF             OFF     
                                   (Insufficient   (Other than
Instrument    (Actual) (Scheduled)       Power)   Power Problem)  COMMENTS
----------     ------  ----------- -----------   ------------- ------------

ACRIM          598          122          0             0

HALOE          500          220          0             0
 
HRDI           391          316          13            0

MLS            236          484          0             0

PEM (axis)     0            720          0             0

PEM (zeps)     111          609          0             0

PEM (neps)     0            720          0             0

SOLSTICE       720          0            0             0         Note 1

SUSIM          587          133          0             0

WINDII         185          535          0             0

Note 1 - No star data March 15-19


Cold side of spacecraft was facing northward:  28.5 days
Cold side of spacecraft was facing southward:   1.5 days


	 	SEVNTFW18