ACE Weekly ACE Weekly 09/04/2012 - 09/10/2012

All ACE spacecraft subsystems are performing as expected.

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Orbit/Attitude:

	Type        Attitude
	Date        09/06/2012
	DOY         250 2012
	Thrusters   2R 4R+ 4R-
	Duration    14:31 min
	Start       14:10:25z
	Stop        14:24:56z
	HGAStart     -4.89deg
	HGAStop      +9.11deg
	SunStart    14.81deg
	SunStop      4.90deg
	SpinStart   5.0590rpm
	SpinStop    5.0619rpm
	Nutation     0.04deg
	Firing      74 pulses
	FuelUsed      0.2267lbs
	FuelRemain  119.7324lbs
	FinalSCMass 1353.992lbs

The next attitude maneuver is scheduled for Monday 09/24/2012.

This attitude maneuver targeted an High Gain Antenna (HGA) angle of 9
degrees so that the next maneuver could be done on Monday 9/24 instead
of Friday 9/21.  The downlink SNR was +7dB which is in line with the
spacecraft's high gain antenna performance.  Around 9 degrees, the
antenna performance drops ~2dB/degree.  But between 10 and 11 degrees,
the antenna performance drops off precipitously (~5db/degree).  The
policy of occasionally targeting 9 degrees to extend the next maneuver
beyond a weekend was implemented in March 2012.  This was done to reduce
the number of maneuvers needed to be performed.

The SWEPAM instrument team has a proposal to keep the spacecraft at
higher sun angles.  Targeting 9 degrees for every maneuver can increase
the average sun angle by ~1 degree.  In that scenario, the benefits are
enough to justify a 9 degree target for every maneuver, if the SWEPAM
proposal is approved.  In the meantime, the option to target 9 degrees
has been submitted for Mission Director approval to provide more data on
the downlink signal strength for consideration of the SWEPAM proposal.

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OCRs:

None


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Activities:

Data Capture:  100%  DOY 246-253 2012


At the end of last week's reporting period, the ULEIS shutter had
autonomously closed due to solar activity.  It re-opened at the
beginning of this week's reporting period, the reopening will be
reported in next week's report
	Mon Sep 3 2012, DOY 247 10:35:10z closed to 25%
	Mon Sep 3 2012, DOY 247 12:41:02z closed to 6%
	Tue Sep 4 2012, DOY 248 12:09:02z opened to 25%
	Wed Sep 4 2012, DOY 249 02:54:22z opened to 100%

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Anomalies:

None