UARS Weekly Status Report

24 July 1998




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

                UARS WEEKLY STATUS REPORT - 24 JULY 1998

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

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

Nothing received.

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

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

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

PEM was 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 accepted by PEM.  PEM has proposed a series of test procedures for 
activation and is waiting response from GSFC.  PEM is also waiting for GSFC
scheduling and implementation of the OBC plan and its operation test procedures.

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

HALOE continues its operations and has been on since July 19.  On about July 29
HALOE will turn off during a "graze" period and will be powered on again around
August 13 until August 20.  The reprocessing of Version 19 HALOE data has been
underway and we have completed up to near the end of 1993, so far.  

A concurrent Processing of Version 18 is continuing at Langley until the end of
1998, when the plan is to continue with Version 19 only.

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

MLS is scheduled to begin south viewing operations on Jul 24.

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

HRDI is currently operating normally.  We are scheduled to operate thru 
July 23rd, then again from August 13th thru the 18th.

The time has come for the HRDI team to say goodbye and good luck to
Dave Ortland.  Dave is leaving the beautiful climate of Michigan for
Northwest Research Associates in Seattle, Washington.  Dave has been
with the HRDI group for over 10 years and has been responsible for
developing many of the HRDI inversion algorithms.  All have been
challenging, but none more so than the retrieval of the stratosphere
wind.  The successful development of this and other HRDI data products
would not have been possible without Dave's hard work, insight and
intuition, and attention to detail.  Dave has performed many scientific
studies using HRDI data.  His most recent work has contributed
significantly to our understanding of the wave inputs to the dynamics
of the tropical stratosphere.  In addition, he has taught a formal
class on inversion theory and informal classes on atmospheric dynamics,
and chaired Ph.D. committees.  Dave may be gone from the HRDI group,
but he will hardly be forgotten.  He will continue to work with the
HRDI group on several outstanding problems.  We wish him all the best
in his new research environs.

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

WINDII WEEKLY REPORT FOR THE WEEK ENDING July 24, 1998

WINDII is currently off, and standing by for activation on August 8.
Team members are very much interested in the observation of OH Meinel
emission by ISAMS, reported in the July 1, 1998 issue of GRL. A contact
has been made to initiate comparison with WINDII OH Meinel observations.

***********
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 has received a total of 401 CD-ROM requests as of 24-July-1998.
There were six orders 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.         
             86 days HAL (4.80) PROD (L1)    (1873R-699C-15F=1159L)
             90 days HAL (4.80) PROD (L3)    (1873R-558C=1315L)
             86 days SOL (4.62) PROD (L2-L3) (2349R-850C=1499L)
              1 day  SOL (4.62) TEST         (1R-1C=0L)
              1 day  SUS (6.3)  PROD         (1R-1C=0L)
            200 days SOL (4.62) PROD (L3)    (200R-200C=0L)
              1 day  SOL (4.62) PROD         (1R-1C=0L)
                    
CDHF pending software upgrades: IDL 5.1, OpenIngres, Fortran V6.5.
                  
***********
FOT
***********

REPORTING PERIOD

This report covers 11 July 1998 (Orbit 37322, GMT Day 192) through 17 July 
1998 (Orbit 37426, GMT Day 198).


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          192/2304     37336       Off
      MLS           193/1008     37343       On/Off test

The beta angle reached a minimum angle of 0.0 degrees on 15 July 1998 (DOY 
196).  The beta angle is now increasing toward a maximum angle of 73.9 
degrees on 05 Aug 1998 (DOY 217).

A Reverse-to-Forward Yaw Around maneuver (number 70) was successfully 
executed in Orbit 37390 at 196/14:13:36 UTC on 15 July 1998.  The SSPP 
Instruments (ACRIM, SOLSTICE, and SUSIM) were enabled.  Due to the SA 
position at 269 degrees, the effective night length of the spacecraft after 
the maneuver was 48 minutes.  Post maneuver analysis of data indicate that 
during the Yaw Around, the end-of-night load bus voltage was 23.8 volts and 
the average depths of discharge (DODs) on Batteries 2 and 3 were 
approximately 23.0 and 22.5 percent respectively.

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 24.6 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 11 July 1998 and 17 July 1998 are provided in 
Appendix D.

The clock error ranged from -10.3 to 9.2 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         =     01
%     OUT-OF-LIMITS  =     06

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

%     FOT     02
%     HALOE   01
%     HRDI    03
%     MLS     01

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

%     FOT     00

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

TRANSPONDER FREQUENCIES:
     Transponder A:  98/146  -  2287.496748
     Transponder B:  98/147  -  2287.499000



GROUND SYSTEM OPERATION

No (0) 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 98/197 show the observatory data loss to be 
20 hours, 45 minutes, 33.784 seconds (an increase of 32.096 seconds since 
last report period).  This is a 0.0347 percent data loss which equals a 
99.9653 percent data capture for the mission.

The increase of 32.096 seconds occurred over two days:

* 0.608 seconds on Day 192 due to hits in the data, and 
* 31.488 seconds on Day 193 due to data omission in dump.

Applications Processor (AP) ground system software testing has been 
suspended waiting release of an operational pack containing version 10.11.


OTHER SIGNIFICANT EVENTS

Planning continues for the the UARS orbit adjust, scheduled for 12 August 
1998, has been canceled.  The orbit adjust will be re-scheduled in the 
future at a time more consistent with reaching the 580 km lower operating 
limit.

The B/D thruster refill effort continues.  Planning continues and the 
engineering thruster tests goal is still 28 July 1998.

Propulsion Module (PM) tank pseudos were added to the daily plots to show 
amount of hydrazine fuel remaining.  Also ran these plots at roughly 
monthly intervals since just before the last orbit adjust (20 October 
1994), in order to determine how much fuel was used and/or lost to leakage 
during this time.  Initial results seemed to indicate that about 4 pounds 
of hydrazine had been inexplicably lost since the last orbit adjust.  The 
loss of fuel seemed to occur gradually over the period from late 1994 until 
late 1996.  However, further analysis showed that the apparent loss of fuel 
was illusory, due to an indicated loss of fuel pressure, which resulted 
from a proportional drop in average load bus voltage over the same time 
span (fuel pressure telemetry calibration is a function of load bus 
voltage).  Based on this information, there is no indication of any 
additional hydrazine fuel usage since the last orbit adjust, and we 
currently estimate about 359 pounds of fuel remain.

The magnetic field model has been calibrated and aligned in the UARS Test 
and Training Simulator (UTTS).  Plans for testing On Board Computer (OBC) 
earth pointing control (using the onboard magnetic software) are being 
developed.

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 list of representative telemetry points to be used as the test set for 
verifying the decommutation subroutines in the re-engineered ground system 
were identified.  One orbit of CDHF data was processed to retrieve a 
baseline test set of data, to be used to verify the new trending system 
software.

FOT continues to support the UARS ground system phase-1 re-host effort to 
the Lockheed Martin SCS-21 system. Work continued on the test script for 
UARS TLM re-host phase-1 demonstration.  Several meetings/telecons with the 
SCS-21 personnel were supported to clarify UARS requirements for UARS re-
host.


MEETINGS

The FOT attended the UARS CMS Year 2K follow-up meeting on 16 July 1998.  
At the meeting, the FOT agreed to assist Carey Myers and the CMS software 
maintenance team in determining the status of the software releases which 
currently reside on the back-up CMS system (UCMSB).  The first step in 
performing any CMS Year 2K testing is to get UCMSB up to speed with the 
necessary CMS software and related support data.  In addition, it was 
decided at the meeting that the FOT should test and release the two pending 
CMS software releases (R7B1V1 and R7B1V2) before any Year 2K related 
software releases are developed and released

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 scheduled for scheduled for 25 August 
1998.

The UARS orbit adjust maneuver scheduled for 12 August 1998 has been 
canceled and will be rescheduled at a later date.


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 A
                       REAL-TIME COMMAND SHEETS
                      Week ending 17 July 1998

ORBIT        AOS         NO.     SUBSYS         REASON
-----        ---        ---      ------         -------  
37336     192/2304     98-239     HALOE    Power OFF
37343     193/1008     98-240     MLS      Test for Scan Mechanism
37352     194/0048     98-241     HRDI     Heater Delay to 125 amp-min
37364     194/2010     98-242     HRDI     Heater Delay to 150 amp-min
37368     195/0243     98-243     HRDI     Heater Delay to 175 amp-min
37406     197/1507     98-244     OBC      Clk Adj fr 0.00 to 20.6 ms/dy
37422     198/1651     98-245     OBC      Clk Adj fr 20.6 to 0.00 ms/dy


_______________________________________________________________

                               APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 17 July 1998

MNEMONIC        STATE      DESCRIPTION                       ORBITS
---------       -----      ------------                      ------
WIEUTEMP        Y-LO     WINDII EU Temperature        37322-426     
QTSISAIF        Y-HI     SSPP Baseplate by SISA I/F   37327,41-3,72,76-                                               
                                                      77,87,94,97-405,
                                                      417-18,21,24

NBRECBI         Y-HI     NBTR B Current               37377,94,417
HRPSEQBIMON     Y-HI     PSE Quiet Bus Current Mon    37377,94

SOSTMPRNTRN     Y-LO     Temperature Entrance         37390-1,94,
                                                      97-403,17
ACTEMPANA2      Y-LO     Temp Sensor Electronics      37394


The following ALERT occurrences were detected:

MNEMONIC                  DESCRIPTION                        ORBITS
---------                 ------------                       ------
OBSZ1OOL     UFLTR Z1 Residual Exceeded 100 Arcsec     37390-1 (YAW)
          



                               APPENDIX C
                 CLOCK & SOLAR ARRAY RATE CORRECTIONS
                      Week ending 17 July 1998


                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT              TIME                 CLOCK RATE CHANGE
     -----              ----                 -----------------
     37406     197/15:12 (16 Jul 98)     from 00.0 to 20.6 msec/day
     37422     198/16:57 (17 Jul 98)     from 20.6 to 00.0 msec/day


_______________________________________________________________

                               APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                      Week ending 17 July 1998


     11 Jul 1998 - GMT Day 192 Beta = 14.7 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  -2.42/-3.68   +0.0/ +0.0  18.2   0.000      0.0
2    +16.8/ -39.2  +6.76/+5.47  +30.8/-14.4  24.2   1.021     23.1
3    +33.6/ -33.6  +5.47/+4.51  +29.6/-15.2  24.2   1.022     22.5

     17 Jul 1998 - GMT Day 198 Beta =  6.6 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/-4.62   +0.0/ +0.0  18.2   0.000      0.0
2   +33.6/ -22.4   +5.47/+4.51  +29.6/-13.6  24.8   1.020     22.0
3   +44.8/  -5.6   +4.51/+2.92  +28.8/-15.2  24.6   1.020     21.3


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



                               APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 17 July 1998


                    NEW ANOMALY REPORTS GENERATED
  AR NO.   SUBSYS       ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------       -----      ----       ---      -----------------
                    None this report period


               ANOMALY CLOSURE INFORMATION RECEIVED
  AR NO.   SUBSYS       ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------       -----      ----       ---      -----------------
                    None this report period


               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
  ------   ------      -----      ----       ---      -----------------
98-044    FOT       See list July 1998    14170 Generic Late Acquisition


	 	SEVNTFW29