ACE Weekly 01/31/2012 - 02/06/2012

All ACE spacecraft subsystems are performing as expected.

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Orbit/Attitude:

No maneuvers were completed this week.  The next attitude maneuver is
scheduled for Tuesday 02/21/2012.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 022-029 2012

ACE is crossing the front of the sun this week.

	Date-0000z  SEV   Sun   HGA   comments
	----------  ----  ----  ---   ---------------------------
	Mon Feb  6  1.03  3.73  3.30
	Tue Feb  7  0.61  2.82  2.71  sun crossing starts   2100z
	Wed Feb  8  0.23  2.04  2.15  sun crossing ends     2100z
	Thu Feb  9  0.31  1.54  1.68  min sun angle 1.50deg 0800z
	Fri Feb 10  0.71  1.64  1.36
	Sat Feb 11  1.12  2.24  1.31
	Sun Feb 12  1.53  3.08  1.58

SEV  Sun-Earth-Vehicle angle.  Sun crossing while SEV<0.26 deg
Sun  Sun angle of spacecraft.  Previous minimum with sun pulse 2.34deg	
HGA  Antenna aspect angle.     Minimizing improves downlink signal

Passes for the week

	Day UTC       hi-rate SNR     Comment
	--- --------- ----------- ---------------------------
	Mon 2010-0010 4 -> -0.5   Hi-rate and playback successful
	Tue 1310-1625   -7dB      No hi-rate ... not unexpected
	Wed                       No pass scheduled
	Thu 1600-2200             No problems expected
	Fri 0950-1450             No problems expected

DSN has been able to receive ACE data with SNRs down to -2dB.  Allowing
the spacecraft to drift to a smaller sun angle and antenna angle helped
improve the signal strength margin allowing successful science playback
on Monday.

Solar flux as measured by F10.7 has been between 100 and 120 this week.
In 2004 when there were minimal problems, the flux was between 90 and
100.  In November 2011 when there were more problems, the flux was
between 150 and 170.

There is minimal risk of data loss at this point.  Of course, a quiet
sun and 100% data capture may not be as interesting as an active sun
with some data loss.

WS1 Update:
ACE telemetry has been successfully received from WS1.  The data from
WS1 matches the data from DSN.

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Anomalies:

None