ACE Weekly 01/09/2013 - 01/15/2013

All ACE spacecraft subsystems are performing as expected.

========================================================================
Orbit/Attitude:

	Type        Attitude       SK-64
	Date        01/15/2013     01/15/2013
	DOY         015 2013       015 2013
	Thrusters   2R 4R+ 4R-     3A 4A
	Duration    6:16 min       38.635 sec
	Start       15:59:50z      17:22:33
	Stop        16:06:06z      17:23:12
	HGAStart    -8.84deg       +8.86deg
	HGAStop     +8.86deg       +9.07deg
	SunStart    12.69deg       13.75deg
	SunStop     13.75deg       13.72deg
	SpinStart   5.0803rpm      5.0813rpm
	SpinStop    5.0813rpm      5.0725rpm
	Nutation     0.19deg        0.11deg
	Firing      32 pulses      Continuous
	FuelUsed      0.1056lbm      0.1326lbm
	FuelRemain  116.9536lbm    116.8212lbm
	FinalSCMass 1351.214lbm    1351.081lbm

The next attitude maneuver is scheduled for Tuesday 01/22/2013.


========================================================================
OCRs:

DOY 011 (01/11/2013) 2101-2124z & 2346-2354z  SIS-053  26 cmds
Two more detector strips (M1B HV: 37,39) were disabled.  The Matrix bias
on Telescope B was raised from 3.73V to 4.26V.  And 9 strips were
temporarily enabled for monitoring for 2 hours (M1B GND: 46,48 and M1B
HV: 2,14,15,18,33,46,62).  Currently 45 M1 detector strips have been
disabled and 2 have been unusable since launch.

========================================================================
Activities:

Data Capture:  99.9997%  DOY 006-013 2013
DOY 012 15:48:27-15:55:36  8 seconds lost over a 7 minute period.  Data
covered by ADC.

========================================================================
Anomalies:

DOY 013 01/13/2013  S-ACE-0657  G13-0001  Duplicate data from DSS-27
After the first command (BOT+2minutes), DSS-27 started searching for the
high data-rate.  However, the spacecraft does not switch to high-rate
until after the 3rd command.  With DSS-27 searching for high-rate, the
MOC decided to send the commands to switch to high-rate before the first
command was verified.  DSS-27 successfully acquired the high-rate data,
but had put a second DCC online while troubleshooting the problem.  The
voice loop was not enabled.  The MOC called the Ops Chief and requested
that DSS-27 disable one of the DCCs.
IMPACT:  Nine minutes of duplicate data.  Duplicate data was sent to
NOAA SWPC which temporarily impacted SIS data processing.  The MOC
software did not redump gaps that occurred during this time.  8 seconds
of data not captured, but covered by realtime (ADC) data.

========================================================================
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

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 4-6deg 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.