ACE Weekly 02/06/2013 - 02/12/2013

All ACE spacecraft subsystems are performing as expected.

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Orbit/Attitude:

	Type        Attitude
	Date        02/12/2013
	DOY         043 2013
	Thrusters   2R 4R+ 4R-
	Duration    21:04 min
	Start       15:59:07z
	Stop        16:20:11z
	HGAStart    -8.72deg
	HGAStop     +9.03deg
	SunStart     9.87deg
	SunStop     10.39deg
	SpinStart   5.0754rpm
	SpinStop    5.0810rpm
	Nutation     0.07deg
	Firing      107 pulses
	FuelUsed      0.3162lbm
	FuelRemain  116.2324lbm
	FinalSCMass 1350.493lbm

The next attitude maneuver is scheduled for Tuesday 02/19/2013.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 034-041 2013

NOAA Space Weather Prediction Center is always looking for antenna
partners.  They are currently working with APL's 18-meter antenna to
track Stereo Beacon data, http://www.swpc.noaa.gov/stereo/.  During the
discussions, APL noted that they have tracked ACE at both high and low
data rates and are capable of commanding to ACE.  This is being included
in this weekly for informational purposes, as ACE operations are
managing pretty well with DSN and NEN's WS1.

Plans are underway to test ranging with ACE and the SSC/Santiago 9-meter
antenna.  The test will be used in planning for the DSCOVR mission and
will occur in the next few months.  The NASA's Near Earth Network (NEN)
has contracts with this and other commercial antennas.  NEN will be
coordinating the test with ACE operations at GSFC.

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Anomalies:

DOY 040  02/09/2013  S-ACE-0647  G12-0009  DSN TLM SLE Provider
The MMOC SLE Software (MUS) was unable to connect to DSN TLM SLE
Provider (ECONNREFUSED).  The FOT requested that JPL restart their SLE
process which fixed the problem.  This problem last occurred on
9/15/2012.  DR#N108628
IMPACT:  Activities delayed 45 minutes.  No impact to NOAA SWPC since
the spacecraft was in RTSW during this time.

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Average Sun Angles With Weekly Attitude Maneuvers

Dates         Avg Sun    Avg SEV   Sun-SEV (indicates extra s/c tilt)
-----------   -------    -------   ----------------------------------
10/18-10/23   11.0deg     5.1deg    5.9deg
10/23-10/28    9.3deg     3.3deg    6.0deg
10/28-11/06    7.3deg     2.0deg    5.3deg
11/06-11/13    8.4deg     3.8deg    4.6deg
11/13-11/20   10.3deg     6.3deg    4.0deg
11/20-11/27   12.7deg     8.6deg    4.1deg
11/27-12/04   14.9deg    10.1deg    4.8deg
12/04-12/11   16.0deg    10.9deg    5.1deg
12/11-12/18   16.8deg    11.3deg    5.5deg
12/18-12/27   16.5deg    10.7deg    5.8deg
12/27-01/03   16.0deg     9.1deg    6.9deg
01/03-01/08   15.2deg     7.2deg    8.0deg
01/08-01/15   13.8deg     6.0deg    7.8deg
01/15-01/22   12.3deg     4.0deg    8.3deg
01/22-01/29   10.6deg     2.4deg    8.2deg
01/29-02/05    9.1deg     3.2deg    5.9deg
02/05-02/12    8.4deg     5.1deg    3.3deg

The following is background information that will be included in each
weekly report.
The project has accepted the SWEPAM team proposal to keep the spacecraft
at larger sun angles with weekly attitude maneuvers.  The SWEPAM-Ion
instrument has a series of channel electron multipliers (CEMs) and
larger sun angles allows more responsive CEMs to measure the solar wind.
The maximum sun angle follows the Sun-Earth-Vehicle angle (SEV).  The
SEV angle is determined by the size/shape of the orbit around L1.  When
the spacecraft antenna is pointed directly towards earth, the
spacecraft's sun angle will be equal to the Sun-Earth-Vehicle angle.
With weekly maneuvers, the average sun angle can be kept 4-8deg more
than the SEV angle.  This results in the spacecraft antenna aspect angle
being kept between 5 and 9 degrees and never pointing directly back at
earth.  For reference, the SWEPAM team prefers sun angles above 13
degrees.  With the current size of the L1 orbit, the sun angle will be
above 13 degrees for ~45% of the time.