ACE Weekly 03/06/2012 - 03/12/2012

All ACE spacecraft subsystems are performing as expected.

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Orbit/Attitude:

Type        Attitude       SK-60
Date        03/12/2012     03/12/2012
DOY         072 2012       072 2012
Thrusters   2R 4R+ 4R-     3A 4A
Duration    16:31 min      85.301 sec
Start       18:39:33z      20:05:20z
Stop        18:56:04z      20:06:46z
HGAStart    -8.53deg       +7.77deg
HGAStop     +7.77deg       +7.78deg
SunStart    18.65deg        5.20deg
SunStop      5.20deg        5.21deg
SpinStart   5.0544rpm      5.0584rpm
SpinStop    5.0584rpm      5.0377rpm
Nutation    0.11deg        0.10deg
Firing      84 pulses      Continuous
FuelUsed      0.2546lbs      0.2928lbs
FuelRemain  123.4660lbs    123.1732lbs
FinalSCMass 1357.726lbs    1357.433lbs

The next attitude maneuver is scheduled for Wednesday 03/28/2012.

The antenna angle before the maneuver was -8.53 degrees.  We generally
prefer to maneuver before the antenna angle reaches 8 degrees.  But in
some situations, it is worth exceeding 8 degrees in order to maneuver on
the next Monday instead of the previous Friday.  MOCR 406 will allow
maneuver planning to exceed an antenna angle of 8 degrees with Mission
Director approval.  The downlink SNR with DSS-27 at -8.53 degrees was
+8dB.  This is 1 dB more than expected given the expected HGA
performance and past DSS-27 performance.

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OCRs:

DOY 068 (03/08/2012) MOCR 406 >8deg antenna angle with MD approval
The current 8 degree antenna angle target is best for most maneuvers.  8
degrees allows most maneuvers to extend to 1 week + 1 weekend.  The High
Gain Antenna performance drops off significantly between 10 and 11
degrees.  An 8 degree target leaves a >2 degree buffer.  But there are
rare occasions where the antenna angle is expected to reach 8 degrees on
Sunday evening.  Instead of maneuvering Friday at 6 degrees, the antenna
target will be allowed to exceed 8 degrees with Mission Director
approval.

DOY 072 (03/12/2012)  1915-1918z  CRIS-011
The Image Intensifier was powered on after being automatically
safeguarded during the previous week's solar activity (DOY 067 1124z).
This OCR was last executed on 01/26/2012.

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Activities:

Data Capture:  100%  DOY 064-071 2012

During last week's solar storm:

* CRIS Image Intensifier safeguarded Wednesday 3/7/2012 (DOY 067 1124z)
and was turned back on Monday 3/12/2012 (DOY 072 1915z).

* ULEIS shutter autonomously closed and reopened
	Wed Mar 07 2012, DOY 067 09:23:08 closed to 25%
	Wed Mar 07 2012, DOY 067 09:53:00 closed to 6%
	Wed Mar 07 2012, DOY 067 10:25:00 closed to 1%
	Sun Mar 11 2012, DOY 071 06:03:24 opened to 6%
	Sun Mar 11 2012, DOY 071 19:56:44 opened to 25%
	Sat Mar 12 2012, DOY 072 08:51:08 closed to 6%
	Sat Mar 12 2012, DOY 072 22:34:35 opened to 25%
	Tue Mar 13 2012, DOY 073 10:14:19 opened to 100%

* SIS real time rates displayed by NOAA SWPC maxed out on Thursday
3/8/2012 0800z-1400z.  Note that the complete SIS science data is not
impacted by the limit in the real-time rates.

* Star scanner false star count tripled on Thursday 3/8/2012.  The star
scanner typically sees 15-20 false stars every 16 seconds and was
reading 45-60 false stars on Thursday.  The star scanner discards the
false stars using internal logic and only valid stars were downlinked in
telemetry.  Note, the star scanner false star count had maxed out at 255
during the 7/14/2000 solar storm.

DSN performed maintenance on their Data Capture and Delivery system.
All data was received in the MMOC.  But the IDR (Intermediate Data
Record) files on the DSN File Delivery Service (FDS) did not have all of
the data.  ACE Science Center receives IDR files from DSN via the FDS.
DSN was notified and the IDR files were recreated with all of the data
for ASC.

Work continues to validate WS1 for ACE.  A command test was performed on
Friday 03/09/2012.  Commands were successfully received by the
spacecraft.  Work continues on setting up ranging and updating the MMOC
configuration.

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Anomalies:

None