ACE Weekly 06/15/2007 - 06/21/2007

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude       SK-44
	Date        06/21/2007     06/21/2007
	DOY         172 2007       172 2007
	Thrusters   2R 4R+ 4R-     1A 2A
	Duration    14:30 min      53.622 sec
	Start       16:04:59z      17:55:15z
	Stop        16:19:29z      17:56:09z
	StartHGA    -7.21deg       +7.48deg
	StopHGA     +7.48deg       +7.52deg
	Firing      74 pulses      Continuous
	FuelUsed     0.24080lbs     0.19728lbs
	FuelRemain  156.4136lbs    156.2163lbs
	FinalSCMass 1390.674lbs    1390.476lbs

The next attitude maneuver is scheduled for Monday, 07/02/2007.

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OCRs:

None

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Activities:

RIONET - Operations will switch from the Closed IONet to the Restricted
IONet on Monday 06/25/2007.  On Tuesday 06/26/2007, the final string of
workstations (String 1) will start to be transitioned to the Restricted
IONet.

Space Link Extension (SLE) - ACE SLE version 2.1 was delivered to the
Library on April 28, 2006.  Installation in the ACE MOC will not occur until
after the MOC is converted to the RIONET.

DSN/SPS/FDF - FDF has started delivering 10 weeks of predictive ephemeris
with each attitude maneuver.  FDF has been notified that when the ACE
maneuvers are spaced apart by more than 2 weeks, DSN SPS will not have the
required 8 weeks of predictive ephemeris.

Planning continues for integrating ACE operations into a multi-mission ops
center (MMOC).

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Anomalies:

DOY 170  06/19/2007  S-ACE-0196  G07-0053  DSS-27 Red
Tuesday's pass was completely lost due to a failure with the DSS-27 Antenna
Motor and Control.  The spacecraft SSR failover occurred at 171-08:21:05.
An additional pass was scheduled for DOY 171 to catch up on SSR playback.
Note, additional time was difficult to acquire since DSS-34, DSS-46 and
DSS-66 were performing maintenance on DOY 170.  DR#G107830
IMPACT:  31 seconds of data not recorded during the SSR failover (171
08:20:35-08:21:05).  No attitude/orbit report for DOY 170.  No clock
calibration for DOY 170 and 171.

DOY 172 (06/21/2007) S-ACE-0197 (S07-0006) - Increase in SBE_CT_B
SSR B Single Bit Error Count (SBE_CT_B) increased from 3125 to 3238 since
last checked on DOY 168 (06/17/2007).  Single Bit Errors are automatically
corrected by the SSR.  The following table gives a history of the Single Bit
Error count for SSR A and SSR B.
IMPACT:  Minimal.  Single Bit Errors are automatically corrected by the SSR
and occur infrequently.

SBE_CT_A              SBE_CT_B
12/01/1999   15       09/06/2003   286
02/25/2003   30       09/22/2004   608
06/05/2003   270      11/15/2004   858
                      11/07/2006   2118
                      01/12/2007   3125
                      06/21/2007   3238

DOY 172 (06/21/2007) S-ACE-0198 (G07-0054) - DSS-46 Red
The range support following the station keeping maneuver was lost due to
DSS-46 unable to move the Y-axis.  FDF requests additional ranging supports
following station keeping maneuver.  Two other ranging supports had already
been scheduled for DOY 173 with DSS-66 and DSS-46.  DR#C105758
IMPACT:  It will take Flight Dynamics longer to accumulate enough range data
to validate the station keeping maneuver.

DOY 172 (06/21/2007) S-ACE-0199 (G07-0055) - ADS Software Error
The Attitude Determination Software (ADS) is not functioning properly on
String 2.  When ADS is running, "Data server received an unknown request"
error messages appear in the TPOCC software window.  This is the same
failure as AR#G07-0049.  The cause remains unknown.
IMPACT:  String 2 was not able to be backup for maneuvers.  If the problem
is not resolved, String 3 will be used when operations is transitioned to
the Restricted IONet.