ACE Weekly 05/07/2014 - 05/13/2014

All ACE spacecraft subsystems are performing as expected.

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Orbit/Attitude:

	Type         Attitude            SK-69
	Date         05/13/2014        05/13/2014
	DOY          133 2014          133 2014
	Thrusters    2R 4R+ 4R-        3A 4A
	Duration      7:44 min         50.843 sec
	Start        15:27:23z         16:20:11z
	Stop         15:34:47z         16:21:03z
	HGAStart     -4.00 deg        +10.19 deg
	HGAStop     +10.19 deg        +10.18 deg
	SunStart     12.25 deg         17.86 deg
	SunStop      17.86 deg         17.70 deg
	SpinStart    5.0012 rpm        5.0031 rpm
	SpinStop     5.0031 rpm        4.9923 rpm
	Nutation      0.06 deg          0.55 deg
	Firing       37 pulses         Continuous
	FuelUsed       0.1204 lbm       0.1716 lbm
	FuelRemain   106.9060 lbm     106.7344 lbm
	FinalSCMass  1341.166 lbm     1340.994 lbm

The next attitude maneuver is scheduled for 05/20/2014.

The attitude maneuver (~10% cold) and station keeping maneuver (7.82%
cold) performance were less than expected.  This may just be an outlier
in maneuver performance.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 124-131 2014

NOAA Space Weather Prediction Center (SWPC) scheduled AFSCN to track ACE
on Thursday 5/8/2014 1000-1045z (DOY 128).  Data from AFSCN is routed
via a NISN SCD at VAFB which also performs frame synchronization on the
data.  Four frames of data were successfully processed by the SCD (Small
Conversion Device) and sent to the MMOC, but NISN (NASA Integrated
Network Services) reported that the rest of the ACE data could not be
frame synchronized.  We (FOT, NISN & NOAA SWPC) do not have insight into
AFSCN to determine the cause of the problem.  The last successful data
flow with AFSCN was 1/6/2014 2302z to 1/7/2014 0155z.  NOAA SWPC has not
scheduled another AFSCN data flow.

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Anomalies:

Update for S13-0001 - B1 Fuel Tank Temperature Anomaly
As mentioned in the previous weekly report, the tank heaters again
started turning off after the maneuver on 5/6/2014.  (Turning off for
~30 minutes every ~2 hours.)  This only lasted ~10 hours and they system
returned to its normal condition (tank heaters always on).  After the
maneuver on 5/13/2014, the tank heaters are again turning off, but this
may again be temporary.


There are occasional minor issues with ACE passes.  If the issues are
minimal, they are not reported in GSFC's SOARS (Space Orbital Anomaly
Reporting System).  Two examples of these occurred in the past week.

DOY 124  05/10/2014  DSS-24 Transmitter Body Over Current interlock
DSS-24 transmitter tripped off at 1849z.  Station reacquired tlm at
1851z with the non-coherent frequency.  Station re-established uplink at
1906z.  DSN DR# G115029
Impact: Minimal.  Short gap redumped at end of pass.  No commanding
required during 17 minute uplink outage.

DOY 133  05/13/2014  DSN Data Capture and Delivery failover
There was a 3 minute real-time delay in telemetry as the DSN Data
Capture and Delivery system (DCD) failed over to a backup.  DSN
backfilled data from the gap. DSN DR# N109566
Impact: None