ACE Weekly 01/20/2010 - 01/26/2010

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude
	Date        01/26/2010
	DOY         026 2010
	Thrusters   2R 4R+ 4R-
	Duration    14:35 min
	Start       16:33:36z
	Stop        16:48:11z
	HGAStart    -7.74deg
	HGAStop     +8.07deg
	SunStart     6.52deg
	SunStop     17.99deg
	SpinStart   5.0518rpm
	SpinStop    5.0556rpm
	Nutation     0.11deg
	Firing      74 pulses
	FuelUsed      0.2333lbs
	FuelRemain  138.2224lbs
	FinalSCMass 1372.482lbs

The next attitude maneuver and SK-53 are scheduled for Thursday
02/11/2010.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 017-024 2010

DSN's Central Data Recorder (CDR) failed on Monday 01/18/2010 and the
ACE Science Center (ASC) stopped receiving CDR files.  The ACE MOC
receives all data (realtime and playback) during the pass formatted as
TLM-3-27 (same as the CDR).  The ACE MOC data was modified slightly to
match the CDR format (96 byte file header & 2 byte block padding) and
sent to ASC.  This was done for DOY 018-022.  ASC received DOY 023 and
DOY 024 from the DSN CDR (each 1 day late).  DSN CDR delivery was
up-to-date on DOY 025.

The last time ASC needed data from the ACE MOC was DOY 073 2007, when
the DSS-66 Ground Receipt Time was incorrect.  The CDR file was
re-sorted by the incorrect GRT and prevented the data from being
processed by ASC.  The ACE MOC data had not been resorted and was sent
to ASC (with appropriate header/padding included).

When ACE transitions to the MMOC, the MMOC will receive data via SLE and
the CDR will save data in the 0161 format.  SLE and 0161 data have
different header formats.


DSS-34 will be unavailable from DOY 027-111 (1/27/2010-04/21/2010).
This leaves 5 DSN antennas for ACE to use.  Of those 5, only DSS-45 is
in the southern hemisphere.  There should still be sufficient southern
hemisphere ranging data for the Orbit Determination team.


The start of operational testing in the MMOC is tentatively scheduled
for Tuesday 02/16/2010 (DOY 047).  All passes starting with DOY 047 will
be taken from the MMOC.  If there are significant problems, operations
would switch back to the old MOC and DSN will be able to reload the
configuration tables for the next day's pass.  The Operations Readiness
Review (ORR) is scheduled for 03/31/2010

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Anomalies:

DOY 024  01/24/2010  S-ACE-0479  S10-0001  Increase in SBE_CT_A
SSR A Single Bit Error Count (SBE_CT_A) increased from 525 to 540 and
SCRUB_ERR_CT_A increased from 35 to 36 since last checked on DOY 022
(01/22/2010).  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   540