ACE Weekly 10/29/2008 - 11/04/2008

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude
	Date        10/31/2008
	DOY         305 2008
	Thrusters   2R 4R+ 4R-
	Duration    12:43 min
	Start       16:08:04z
	Stop        16:20:47z
	HGAStart    -6.75deg
	HGAStop      7.46deg
	SunStart    15.76deg
	SunStop      6.08deg
	Nutation     0.32deg
	Firing      64 pulses
	FuelUsed      0.2107lbs
	FuelRemain  146.9396lbs
	FinalSCMass 1381.200lbs

The next attitude maneuver is scheduled for Friday 11/14/2008.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 300-307 2008

There is a higher than normal risk of data loss from October 2008 through
February 2009.  If there are problems with the passes, it may not be
possible to acquire additional DSN time.  This higher-risk period has been
occurring every winter for the past couple of years.  For more information
refer to 10/14/2008 weekly.


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Anomalies:

DOY 304  10/30/2008  S-ACE-0369  G08-0104  DSS-46 TCP Configuration
The station operator did not correctly configure the TCP to send high-rate
data to the ACE MOC (low latency).  The FOT contacted the station and
requested that the low latency channel be switched to high-rate data.
DR#C106604.  This same problem occurred on 10/15/2008 (AR#G08-0096
DR#C106579).  DSN is reviewing the desktop/TCP configuration.  
IMPACT:  Manual intervention required.  Activities delayed 23 minutes.

DOY 305  10/31/2008  S-ACE-0370  G08-0105  AC2WS1 Hard Drive Failure
AC2WS1 root drive failed.  SysAdmins notified.
IMPACT:  Minimal.  String 2 can still function as a backup for operations.

DOY 305  10/31/2008  S-ACE-0371  G08-0106  Unable to Log In AC2PC1
AC2PC1 is used for maneuver planning.  While attempting to log in, the
incorrect password was entered.  After successfully entering the password, a
dialog box appeared "The System Log is full".  No accounts were able to log
into the computer.  After 20 minutes, the FOT was able to log into the
computer and plan the maneuver.  The problem could not be reproduced for the
SysAdmins.
IMPACT:  A second computer (ACETLANPC) was available for maneuver planning
if AC2PC1 was completely unavailable.

DOY 308  11/03/2008  S-ACE-0372  G08-0107  DSS-46 SLE CMD Problems
The ACE MOC was able to successfully BIND to DSS-46 and send commands, but
the commands were never radiated.  After several different troubleshooting
actions, the station unloaded and reloaded desktop.  Commands were then
successful.  DR#C106610
IMPACT:  Activities delayed 25 minutes.

DOY 308  11/03/2008  S-ACE-0373  G08-0108  DSS-46 TLM Problems
The station's TCP was having difficulty processing telemetry frames for
unknown reasons.  Errors were being found in the Convolutional and
Reed-Solomon Decoders resulting in ~0.1% data loss over 40 minutes.  The FOT
requested that the station increase the RF Loop Bandwidth on the receivers
and this resolved the problem.  DR#C106611
IMPACT:  All data was captured through redumps.  Although 0.1% data loss is
per frame, this corresponds to a 10% loss of complete major frames (42
minutes).

DOY 309  11/04/2008  S-ACE-0374  G08-0109  SSR Not Idled
The automation software is designed to Idle the SSR 15 minutes before End Of
Track and perform redumps with the time remaining.  However, the automation
software failed to execute this procedure.  The SSR was still in playback
when the spacecraft transitioned to low-rate.  When this occurs, the SSR
remains stuck in playback mode (01/12/2005 AR#S05-0002 and 12/01/2005
AR#G05-0148).
IMPACT:  The procedure S_OPS_REC_PLBK handles this contingency by idling the
SSR at the beginning of the next support and redumping any missing data.

DOY 309  11/04/2008  S-ACE-0375  G08-0110  Postpass Dumplist Not Correct
The postpass calculation of redumps used the wrong TPOCC history file to
determine the end of the SSR segment.  Manual review of the pass uncovered
the problem and the dumplist was corrected.  The problem appeared because 2
passes were scheduled for 1 day.  MOCR#1379 has been opened to correct the
offline tool.
IMPACT:  38 minutes of data would have been lost if the problem had not been
caught.