UARS Weekly Status Report

15 May 1998





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                UARS WEEKLY STATUS REPORT - 15 MAY 1998

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

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

SOLSTICE delivered v. 4.60 of its processing software to CDHF this week,
and testing is underway.  This version is a major revision, with significant
improvements in many of our processing and calibration algorithms, and we
expect that the new versions (data version 10) of our final science products
will also be significantly improved.

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

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

A new version of an SUSIM MgII index, V19r3, is now available through
SUSIM's WWW site.  The new index correlates with V19r2 at about 0.995.
See:

http://wwwsolar.nrl.navy.mil/susim_uars_mgii_index.html

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

PEM/AXIS became active on May 10.  It is currently generating energy
deposition from inverted X-ray spectra for each of its 16 look directions.

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.  PEM has proposed a series of test procedures
for activation and is waiting response from GSFC.

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

Nothing received.

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

The MLS instrument has been powered off since May 2. MLS is scheduled to
begin south viewing operations on 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 notified users about the installation of UCSS release 10.0.
The build has been scheduled for May 27th and should require about 10 hours of
downtime during day shift. Users were requested to send comments, reservations,
or impact statements to the PAC account.

The CDHF has received a total of 388 CD-ROM requests as of 15-May-1998.
Two orders were 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.           
                  26 days PEM (3.32) PROD (1379R-1238C=141L)
                  67 days HAL (4.80) PROD (L1) (1868R-67C-1F=1800L)
         
The CDHF added a javascript file to our web server which routes users looking
for the UARS Science web pages to the UMPGAL server.

CDHF pending software upgrades: IDL 5.1, OpenIngres, UCSS.
                  
***********
FOT
***********

REPORTING PERIOD

This report covers 02 May 1998 (Orbit 36273, GMT Day 122) through 08 May 
1998 (Orbit 36378, GMT Day 128).


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
            MLS       122/2330     36288      Off

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

A Reverse-to-Forward Yaw Around maneuver (number 68) was successfully 
executed in Orbit 36327 at 14:20:20 UTC on 05 May 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 24.5 volts and 
the average depths of discharge (DODs) on Batteries 2 and 3 were 
approximately 22.5 and 22.0 percent respectively.

Two manually generated SSPP Stellar Offset experiments requested by 
SOLSTICE operations were performed on GMT days 125 and 127

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 1.3 degrees C.  Additional battery performance 
data for each battery on 02 May 1998 and 08 May 1998 are provided in 
Appendix D.

The clock error ranged from -10.8 to +0.6 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 =     05

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

%     FOT     01
%     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 98/127 show the observatory data loss to be 
20 hours, 43 minutes, 11.156 seconds (an increase of 2.368 seconds since 
last report period).  This is a 0.0357 percent data loss which equals a 
99.9643 percent data capture for the mission.

The increase of 2.368 seconds occurred over a four day period:

0.922 seconds on Day 122 due to hits in the data,
0.224 seconds on Day 124 due to hits in the data,
0.576 seconds on Day 125 due to hits in the data, and
0.576 seconds on Day 125 due to hits in the data.

All missing level-0 data resulting from the Building 23 power outage was 
processed by about noon on 04 May 1998.  The data loss calculations were 
included in the report for last week.

The FOT experienced along track transition comparisons in excess of 1.5 km 
when processing the ephemeris on the CMS this week.  The out-of-limit 
comparisons occurred on all three of the ephemeris delivery days.  FOT 
contacted the FDF representative regarding his analysis of the need to 
transition to a more frequent ephemeris delivery.  The FDF representative 
stated that due to the upcoming increase in solar flux, FDF will need to 
start providing a daily ephemeris solution to the FOT beginning sometime in 
the next few weeks.

The FOT did not perform any IP testing this week.  All efforts are being 
directed to database development to support the planned OBC Flight Software 
update.

The FOT finished the preliminary modifications to the OBCSTF resident POCC 
database this week.  Database version 67 was generated and delivered (on 
tape) to the MSOCC software coordinator (Huong Truong) on 07 May 1998.  The 
MSOCC software coordinator will process database on the AP and install it 
onto PE 49 (E.Z. BlockUs test pack).  The FOT will spend the next several 
weeks testing database 67 and making any necessary corrections.



OTHER SIGNIFICANT EVENTS

Work on the upgrade of the OBC Power Monitor (PMON) continued. Tested the 
programmers version of the new AP software with database 66 (test database, 
not the new database) on Thursday, 07 May.  All features worked as 
expected.  Began testing of the new flight software with the new database.  
Found a few minor problems with the database, and a telemetry formatting 
problem in the flight software (now corrected).  Testing will continue this 
week.

Work continues on the UARS August orbit adjust planning, The Branch Head of 
the Propulsion Branch (Dennis Asata), informed the FOT that analytical 
analysis of the UARS hydrazine pipe refill showed a peak pressure 
calculation of 1500 psi.  This pressure, though not zero risk, should be 
safe with the exception that the pressure transducer may change scale due 
to the pressure surge.  He indicated that a test with a latch valve should 
be performed to confirm the calculation.

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.



FUTURE SIGNIFICANT EVENTS

The next UARS Yaw Around Maneuver is currently scheduled for 16 June 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 A
                       REAL-TIME COMMAND SHEETS
                      Week ending 08 May 1998

ORBIT      AOS        NO.     SUBSYS    REASON
-----      ---       ---      ------    -------  
36288     122/2330   98-156    MLS     Power OFF
36288     122/2330   98-157    OBC     Clk Adj 20.6 to 0.00 msec/day




_______________________________________________________________

                               APPENDIX B
                  OUT-OF-LIMITS & ALERTS OCCURRENCES
                      Week ending 08 May 1998

MNEMONIC     STATE     DESCRIPTION                       ORBITS
---------    -----   ------------                      ------
HRPTSPBIMON  Y-HI    PTS Pulse Bus Current Monitor   36171,235,39
QTSISAIF     Y-HI    SSPP Baseplate by SISA I/F      36281,94,96,309-                                                                                          
                                                     18,24,39-40,42,46,53-            
                                                     63,69     
WIEUTEMP     Y-LO    WINDII EU Temperature           36302,03,04-64,69-78
SOSTMPRNTRN  Y-LO    Temperature Entrance            36327,39,42,53-54,58-                                                               
                                                     59,69
SOSTMPRBLFT  Y-LO    Temperature Bot_Left_Front      36339,
ACTEMPANA1   Y-LO    Temp PCU Board 1                36342,44,64


The following ALERT occurrences were detected:

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



                               APPENDIX C
                 CLOCK & SOLAR ARRAY RATE CORRECTIONS
                      Week ending 08 May 1998

                      CLOCK DRIFT RATE ADJUSTMENTS

     ORBIT              TIME                 CLOCK RATE CHANGE
     -----              ----                 -----------------
     36288     122/23:37 (02 May 98)     from 20.6 to 00.0 msec/day


_______________________________________________________________

                               APPENDIX D
                    UARS BATTERY PERFORMANCE DATA
                      Week ending 08 May 1998

     02 May 1998 - GMT Day 122 Beta = 13.5 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   +728.0/+728.0   -2.73/-3.68   +0.0/ +0.0   18.4  0.000     0.0
2    +39.2/  -5.6   +7.41/+5.79  +32.0/-15.2   23.8  1.018    24.0
3    +39.2/ -16.8   +6.11/+4.51  +31.2/-16.0   23.7  1.021    23.3

     08 May 1998 - GMT Day 128 Beta = 10.8 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    -3.68/-4.94   +0.0/ +0.0   18.4  0.000     0.0
2   +89.6/  -5.6    +5.15/+3.87  +30.4/-13.2   25.8  1.024    21.5
3   +56.0/ -11.2    +3.87/+2.60  +29.2/-14.4   25.8  1.021    20.8


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



                               APPENDIX E
                         UARS ANOMALY REPORTS
                      Week ending 08 May 1998


                    NEW ANOMALY REPORTS GENERATED
  AR NO.   SUBSYS       ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------       -----      ----       ---      -----------------
  98-023   FOT          36274     122/0050Z   N/A      TAC #2 Crashed


                 ANOMALY CLOSURE INFORMATION RECEIVED
  AR NO.   SUBSYS       ORBIT      TIME       TTR      PROBLEM/DATA LOSS
  ------   ------       -----      ----       ---      -----------------
  98-022   FOT          36272     121/21:36            TAC 2 CRASH
  98-023   FOT          36274     122/00:50            TAC 2 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
  ------   ------       -----      ----       ---      -----------------
  98-021    Generic Late Acq for May 1998 (Open until 31 May 1998).



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