ACE Weekly 09/24/04 - 09/30/04

All ACE spacecraft subsystems are performing nominally.  A "Dog-Leg" 
attitude maneuver was successfully executed on 09/27/04.  The next attitude 
maneuver is scheduled for 10/08/04.

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Orbit Events:

The next SEZ crossing will occur in the Nov-Dec time frame.

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

None

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Ongoing Activities:

TAPS:
- Installation of TAPS release 4.3 on the Backup System occurred on 07/20/04.
   -- FOT testing of this release has completed.
- Installation of TAPS Release 4.3 on the Prime System is TBD.

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Automation (ROBOTT):

- ROBOTTv0.9 delivered to String 1 on 09/27/03 (OCR GND_145).
   --  Performing operations in "Auto" mode on String 1.
   -- 13 DR fixes in this release.
         --- 12 DRs have been verified by the FOT to date.
   --  5 DRs have been written against this release, however none are 
mission critical.

============================================================================
Extra Spacecraft Activities:

SWEPAM Calibration was not attempted on Monday (09/27/04) due to the length 
of the attitude maneuver activities.  After consulting with Jim Griffee the 
calibration activity was completed successfully on Tuesday (09/28/04).

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

DOY 04271 (09/27/2004) ACE Anomaly G04-0112 - MAD 26m (DSS-66) RNS Overflow
At 13:30:02, the FOT started to receive VC2 sequence errors (BOT 
13:10).  At 13:33, the FOT reported the degraded data to DSS-66 and JPL 
Comm.  At 13:38, JPL Comm reported seeing UDP dropouts.  At 13:41, JPL Comm 
informed the FOT that the problem was at the station (Madrid).  At 13:44, 
DSS-66 confirmed the problem was at the station (RNS overflow).  At 
13:45:06, the VC2 sequence errors stopped.  However, there were brief 
instances of VC2 sequence errors later in the pass.    IMPACT:  None.  All 
data subsequently retrieved via playback.   DR# M102757.

DOY 04273 (09/29/2004) ACE Anomaly G04-0113 - GDS 26m (DSS-16)  Antenna Stopped
At 17:53:10 FOT noticed a TLM dropout.  Queried DSS-16, and station 
reported that the antenna had stopped, carrier was down and  they were 
attempting to bring the antenna back on point.
At 18:07:00 DSS-16 notified FOT they were unable to support and that DSS-27 
was currently configuring for support.  IMPACT:  Minimal.  SSR playback had 
completed so loss of realtime data was the only impact.  All telemetry 
subsequently retrieved via next day's playback.  DR# G104848

DOY 04274 (09/30/2004) ACE Anomaly G04-0114 - GDS 26m (DSS-16) Commanding 
Not Enabled
At 15:05 FOT noted that the /no_op command did not reach the spacecraft 
during g_precal.
At 15:15 BOT occurred w/DSS-16.  During the execution of g_initial_contact 
the first command "BIN_CLEAR" did not reach the spacecraft.  As a result 
the command was retransmitted multiple times(15).  FOT notified DSS-16 and 
they "enabled" commanding.  IMPACT:  Delayed pass activities.  Without FOT 
intervention, no commands would have reached the spacecraft.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Glen A. Miller
ACE Flight Operations Observatory Engineer
Honeywell Technology Solutions Inc.
Goddard Space Flight Center
Building 14, Room W10A
Mail Stop 428.2
Greenbelt, MD 20771

Office: 301-286-7071
Pager: 800-425-3174
Fax:    301-286-1729
gamiller@pop500.gsfc.nasa.gov
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~