ACE Weekly 05/25/2007 - 05/31/2007

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude
	Date        05/25/2007
	DOY         145 2007
	Thrusters   2R 4R+ 4R-
	Duration    14:30 min
	Start       15:30:39z
	Stop        15:45:09z
	StartHGA    -7.21 deg
	StopHGA     +7.55 deg
	Firing      74 pulses
	FuelUsed     0.2410lbs
	FuelRemain  156.8804lbs
	FinalSCMass 1391.141lbs

The next attitude maneuver is scheduled for Friday, 06/08/2007.
Station-keeping maneuver #44 is tentatively planned for Thursday,
06/21/2007.

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OCRs:

None

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Activities:

RIONET - An operational test of String 2 on RIONet was performed Wednesday
05/30/2007, DOY 150.  Testing on String 2 with the new ROBOTT installation
continues.  Operations will switch to String 2 and RIONet is tentatively
scheduled for Tuesday, 06/26/2007, DOY 170.  But before that can happen, the
telemetry flow to ASC and NOAA will need to be tested from the RIONet.  The
upcoming shuttle mission (launch target June 8) will result in a network
freeze which will need to be scheduled around.

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 is evaluating their ephemeris generation in response to
the ongoing SPS problems with pass numbers and viewperiods.  This impacts
the ACE, SOHO, WIND and POLAR missions.  The impact to ACE occurs more often
since ACE has the shortest ephemeris files (59-day).  The FDF evaluation is
expected within the next few weeks.

The ops concept for the Multi-Mission Ops Center (MMOC) was presented on
Thursday 05/30/2007, DOY 150.  The next step is an architecture plan and
then an implementation plan.  Once the plans are approved, work will begin
developing and configuring new systems for the MMOC.

Work is beginning on re-engineering the attitude determination ground
software.

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Anomalies:

DOY 145  05/25/2007  S-ACE-0186  S07-0005  S3DPU_I Red High Limit Violation
S3DPU current (S3DPU_I) briefly violated the red high limit (RH > 145mA).
	2007-145-16:38:52 - 16:38:54  148.176-156.016mA
IMPACT:  Minimal.  Likely increased processing from increase in solar wind
density.  The average current usage has remained stable.

DOY 146  05/26/2007  S-ACE-0187  G07-0044  DSS-66 Uplink/Downlink Problems
Problems with both the uplink and downlink starting at 1324z. At 1345z,
there was a loss of uplink lock on the spacecraft receivers.  End-Of-Track
was at 1350z.  DR#N104380
IMPACT:  Minimal.  SSR playback had already been completed.  End of pass
state of health checks delayed due to telemetry outages.  ROBOTT/C&C froze
due to the telemetry outages and rebooted.  End of pass procedure did
complete successfully.  No commanding was needed during the last 5 minutes
when uplink was lost.

DOY 143  05/23/2007  S-ACE-0188  G07-0045  String 2 Tape Drive Failure
The ground system string 2 tape drive failed.  Hardware maintenance replaced
the hard drive on 05/30/2007.
IMPACT:  Minimal.  String 2 is still being tested for the Restricted IONet.