ACE Weekly 09/14/2007 - 09/20/2007

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude
	Date        09/20/2007
	DOY         263 2007
	Thrusters   2R 4R+ 4R-
	Duration    12:19 min
	Start       19:42:50z
	Stop        19:55:09z
	HGAStart    -7.48deg
	HGAStop     +6.70deg
	SunStart     9.24deg
	SunStop     14.90deg
	Nutation     0.24deg
	Firing      63 pulses
	FuelUsed      0.2081lbs
	FuelRemain  154.2232lbs
	FinalSCMass 1388.483lbs

The next attitude maneuver is scheduled for Monday, 10/08/2007.

Note, sun angle and post-maneuver nutation have been added to the maneuver
summary.  The nutation is the half angle.  For example, the post-maneuver
sun angle varied between 14.66 and 15.14 degrees and the antenna angle (HGA)
varied between 6.46 and 6.94 degrees.  The nutation period is 8 seconds ...
two-thirds of the spin period.

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OCRs:

None

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Activities:

Closed IONet cables were removed on Monday 09/17/2007.  ACE had transitioned
from the Closed IONet to the Restricted IONet back in July 2007.

The DOY 260 pass was shortened by 1 hour and the time was given to the
recently launched SELENE mission.  SSR playback was caught up during the
following support.

Space Link Extension (SLE) Testing status
DSN continues to troubleshoot SLE problems with the 26m subnet.  The
previous telemetry problem with DSS-46 was due to an incorrect destination
code in the new desktop configuration file.  A 3 hour test with DSS-66 on
Thursday 09/20/2007 had a successful bind and telemetry flow, but commands
were not being transmitted to the spacecraft.  The cause of the problem
remains unknown.

An ACE MOC SLE software upgrade (v3.1) is tentatively scheduled for Thursday
09/27/2007.  This upgrade uses the newest libraries from the Vega/Anite
commercial software and fixes other minor issues.  The developers have
scheduled a test of the software upgrade with DSN's Test Facility (DTF-21)
for Friday 09/21/2007.  DSN may also use this time to troubleshoot the 26m
subnet problems.

Multi-Mission Ops Center (MMOC)
Planning continues to look for ways to compress the schedule for
transitioning to the MMOC.

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Anomalies:

DOY 253  09/10/2007  S-ACE-0225  G07-0079  Incorrect HGA-FOT Attitude Tool
The FOT inherited several tools for analyzing the output from ADS attitude
software.  One of these tools has occasionally been incorrect when
calculating the antenna angle (HGA).  A MOCR will be submitted to correct
the calculation.
IMPACT:  Minimal.  The tools are for internal checks.  The Attitude/Orbit
Reports sent to ASC are still correct.

DOY 260  09/17/2007  S-ACE-0226  G07-0080  Data Flow from Internal DSN Test
DSN scheduled an internal data-flow test for resolving the 26m SLE telemetry
problem.  The data flow was supposed to be internal and not sent to the MOC.
Unfortunately, DSN flowed data to the MOC.  The data was old data from DOY
241 2006 (1740-1744z).
IMPACT:  Minimal.  Time and effort troubleshooting impact from the data
flow.

DOY 262  09/19/2007  S-ACE-0227  G07-0081  ACEDDS Hard Drive Failure
On DOY 262, the /home drive failed on ACEDDS (Data Distribution Server).
The SysAdmins backed up and restored the hard drive before the pass on the
following day (DOY 263).
IMPACT:  Minimal.  The ROBOTT automation sent page notifications through the
backup (WINDDS).  The latest DSN schedule was not downloaded during this
time, but there were no changes to the ACE passes.

DOY 263  09/20/2007  S-ACE-0228  G07-0082  TAPS2 Routing
For unknown reasons, the AC2TAPS2 trending computer lost the default route
to the ACE MOC firewall.  The SysAdmins restored the route on the same day.
IMPACT:  Minimal.  The telemetry data was captured by AC1TAPS1 trending
computer and copied to AC2TAPS2 after the routing had been corrected.

DOY 263  09/20/2007  S-ACE-0229  G07-0083  AC3PR3 Printer JetDirect Card
The HP JetDirect card has failed on the trending printer.  Hardware
Maintenance has been notified.  Waiting to see if replacing the JetDirect
card resolves the ongoing printer problems.
IMPACT:  Time and effort troubleshooting.