ACE Weekly 05/12/2010 - 05/18/2010


All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude
	Date        05/12/2010
	DOY         132 2010
	Thrusters   2R 4R+ 4R-
	Duration    16:28 min
	Start       22:08:18z
	Stop        22:24:46z
	HGAStart    -7.95deg
	HGAStop     +7.43deg
	SunStart    14.36deg
	SunStop      6.28deg
	SpinStart   5.0592rpm
	SpinStop    5.0636rpm
	Nutation     0.18deg
	Firing      84 pulses
	FuelUsed      0.2616lbs
	FuelRemain  136.5600lbs
	FinalSCMass 1370.820lbs

The next attitude maneuver is scheduled for Friday 05/21/2010.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 129-136 2010

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Anomalies:

DOY 133  05/13/2010  S-ACE-0504  S10-0003  Increase in SBE_CT_A
SSR A Single Bit Error Count (SBE_CT_A) increased from 540 to 780 and
SCRUB_ERR_CT_A increased from 36 to 52 since last checked on DOY 129
(05/09/2010).  SBE_CT is tracked as a measure of SSR health.
IMPACT:  Minimal.  Single Bit Errors are automatically corrected by the
SSR.  No non-correctable errors (Hard Single Bit Errors & Double Bit
Errors) have occurred throughout the mission.

	       SBE_CT_A  SBE_CT_B
	1999   15
	2000
	2001
	2002
	2003   270       286
	2004             858
	2005
	2006             2118
	2007   510       3238
	2008             4533
	2009   525       6839
	2010   780


DSS-24 has had problems with their S-Band HEMT (High Electron Mobility
Transistor) since DOY 136 (Sunday).  This has affected data capture for
Wind, Cluster and Chandra missions.  ACE, however, was able to capture
all data with the DSS-24 pass on DOY 138 (Tuesday) due to the stronger
ACE downlink signal.