ACE Weekly 04/02/2014 - 04/08/2014

All ACE spacecraft subsystems are performing as expected.

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Orbit/Attitude:

	Type         Attitude
	Date         04/08/2014
	DOY          098 2014
	Thrusters    2R 4R+ 4R-
	Duration     9:53 min
	Start        20:24:13z
	Stop         20:34:06z
	HGAStart     -8.34 deg
	HGAStop      +8.75 deg
	SunStart     12.32 deg
	SunStop      12.79 deg
	SpinStart    4.9886 rpm
	SpinStop     4.9907 rpm
	Nutation      0.18 deg
	Firing       50 pulses
	FuelUsed       0.1585 lbm
	FuelRemain   107.7584 lbm
	FinalSCMass  1342.018 lbm

The next attitude maneuver is scheduled for Tuesday 04/15/2014.

A summer campaign to increase the spacecraft sun angle will start next
week.  More information will be included in next week's report.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 089-096 2014


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Anomalies:

Update on Anomaly #G14-0005 (S-ACE-0677) DSS-15 Earth Receive Time (ERT)

The DSN Earth Receive Time continues to have occasional problems after
the spacecraft's data-rate change (from low-rate RTSW to high-rate).
The problem is occurring in less than half of ACE's passes at Goldstone.

	2014-071-21:14:12  DSS-15  ERT behind by 0.271 seconds
	2014-082-20:54:40  DSS-24  ERT behind by 0.182 seconds
	2014-084-20:15:34  DSS-15  ERT behind by 0.273 seconds
	2014-089-16:36:28  DSS-15  ERT behind by 0.091 seconds
	2014-092-16:20:13  DSS-15  ERT behind by 0.092 seconds	
	2014-096-15:39:21  DSS-15  ERT behind by 0.092 seconds
	2014-098-20:02:22  DSS-24  ERT behind by 0.091 seconds

DSN reports that this is an intermittent problem (DR# G114836/AR 118839)
with the Receiver, Ranging, and Telemetry (RRT) software v11.3.6 that is
currently undergoing soak testing.  The ERT is behind by an integer
multiple of telemetry frames (high-rate = 0.091 seconds per frame).  DSN
believes that halting and re-acquiring the TLP corrects the ERT.

The clock reports sent to ASC and NOAA are not significantly impacted by
the slight offsets.  Updated clock reports have been sent to ASC.  Note
that one clock report (DOY 096) did result in the day boundary being
rounded to a different second, which was manually rectified by ASC.

The FOT has told DSN that this is not critical enough to stop the soak
testing and that DSN can proceed with the halt/re-acquire TLP to correct
the ERT.