ACE Weekly 08/02/02 - 08/08/02

All ACE spacecraft subsystems are performing nominally. No maneuvers were 
executed this week. The next attitude maneuver is scheduled for 08/13/02.

============================================================================
OCRs Executed:

SWPX-035, DOY 02218, 1614UT - Compensate for gain loss over the past 10 months.
The SWEPAM team will need to monitor the realtime data during commanding to 
verify that the increased high voltage level does not cause excessive counts.

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Ongoing Activity:
The engineering test to determine the new HGA constraint is continuing. The 
current constraint is 6.0 deg., with current tests reaching 6.5 degrees.

The FOT has been monitoring the Signal Strength, the MFR AGC levels, and 
the Signal-to-Noise Ratios(SNR). The drop in RF levels from an HGA angle of 
0 deg to 6 deg has been approximately 3dB. There has been no loss of 
telemetry due to the increased HGA angles.  Once all analysis has been 
completed, the new HGA constraint will be determined.

The following HGA angles and range values are from FDF.
Man Date Pre Man   Post Man    Earth-ACE Range
03/28/02 -4.58 deg  +4.38         1408287 km
04/04/02 -4.35      +4.50         1414808
04/11/01 -5.09      +3.79         1428491
04/18/02 -5.16      +3.85         1440512
04/26/02 -5.77      +5.56         1455949
05/06/02 -5.72      +5.43         1493008
05/17/02 -5.81      +5.31         1527979
05/28/02 -4.34      +4.88         1550263
06/06/02 -2.38      +5.96         1576064
06/20/02 -6.57      -3.66         1590405
06/26/02 -6.43      +5.94         1592458
07/12/02 -6.5       +6.5          1598879
07/30/02 -6.5       +6.5          1567441

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TPOCC Release 5.2 String 2 Testing Status

Testing on String 2 is still in progress.  Expected completion date is 
August 19, 2002.

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26m Automation Demo Status

An additional test was supported on August 2nd. The FOT has submitted the 
test results and are awaiting DSN's r`esponse to the discrepancies reported.

============================================================================
Anomalies:

DOY 02217 (08/05/2002)ACE Anomaly #G02-0089 DSN - Delayed AOS
Station failed to bring telemetry online at scheduled BOT of 
1255UT.  Station reported having receiver problems.  At ~ 1305UT the 
station reported that they had the wrong exciter frequency 
selected.  IMPACT:  AOS was delayed by ~ 23 minutes however all data was 
recovered.

DOY 02217 (08/05/2002)ACE Anomaly #G02-0089 DSN TGC Backup Channel Put Online
At 1605UT telemetry ceased flowing into the MOC.  The station brought the 
TGC backup channel online to correct the problem. Telemetry was restored at 
1609UT, and no further problems were encountered.  IMPACT:  Unable to get a 
complete autonomy dump causing TPOCC to register false miscompares with the 
Ground Reference Image (GRI).

DOY 02220 (08/08/2002)ACE Anomaly #G02-0091 DSN - Station AGC Level Very Low
At approximately 1550UT, the MOC observed that station receiver AGC levels 
were dropping rapidly, reaching -130 dB/mW by 1551UT. By ~ 1623UT, the 
level had fallen to -140 dB/mW.  The station was unable to correct the 
problem in R/T.  IMPACT:  End of day activities could not be performed due 
to low AGC levels which introduced too much risk for further commanding.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Glen A. Miller
Honeywell Technology Solutions Inc.

ACE Flight Operations Team
Goddard Space Flight Center
Building 14, Room W10A
Mail Stop 428.2
Greenbelt, MD 20771

Office: 301-286-7071
Fax:    301-286-1729
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~