ACE Weekly 06/28/02 - 07/04/02

All ACE spacecraft subsystems are performing nominally. No attitude 
maneuvers were executed this week. The next attitude maneuver is scheduled 
for 07/12/02.

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Ongoing Activity:
The engineering test to determine the new HGA constraint is continuing. The 
current constraint (as of 6/3/02) is 6.0 deg, with current tests reaching 
6.5 degrees.  The attitude maneuver on 7/12/02 is expected to target +6.5 deg.

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 (expected)

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TPOCC Release 5.2 Testing Status

Testing of TPOCC Release 5.2 on String 3 is 70% completed.  No major 
problems identified to date. Target completion date is July 26th.

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

DOY 02190 (07/09/2002) - ACE Anomaly #G02-0083 JPL Power Outage
JPL experienced a power outage at approximately 1415z.  No telemetry was 
received for the duration of the pass from that time.  In addition, the MOC 
lost all command capability with the spacecraft as well.  An additional 
pass was scheduled for the next day and all telemetry was 
recovered.  IMPACT:  Science center data was delayed 24 hours.  DR# N100528

DOY 02192 (07/11/2002) - ACE Anomaly #G02-0084  Station Communications 
Processor (SCP) Reboots
1) From 1508-1522z DSN Monitor Blocks were offline. (DR# G101374)
2) From 1633-1636z, 1742-1749z, no telemetry was received from station 16. 
(DR# G101375)
All three outages were due to SCP errors at station 16 which required a 
reboot of the SCP.  All spacecraft telemetry was recovered.  IMPACT:  No 
DSN Monitor Data for the first 13 minutes of the pass.


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Glen A. Miller
Honeywell Technical Services Inc.

ACE Flight Operations Team
Goddard Space Flight Center
Bldg. 14, Rm. W10A
Mail Stop 428.2
Greenbelt, MD 20771

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