ACE Weekly 06/08/2007 - 06/14/2007

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude
	Date        06/08/2007
	DOY         159 2007
	Thrusters   2R 4R+ 4R-
	Duration    13:31 min
	Start       15:44:12z
	Stop        15:57:43z
	StartHGA    -7.17deg
	StopHGA     +7.42deg
	Firing      69 pulses
	FuelUsed     0.2259lbs
	FuelRemain  156.6544lbs
	FinalSCMass 1390.914lbs

The next attitude maneuver and station-keeping maneuver #44 are scheduled
for Thursday, 06/21/2007.

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OCRs:

DOY 164 (06/13/2007)  GND-182
The MOC PCs are being upgraded for IT Security compliance.

DOY 164 (06/13/2007)  1500-1700z  GND-183
The real-time data flow from GSFC to NOAA's Space Environment Center
(Boulder, CO) and to the ACE Science Center (Caltech) was transitioned from
the Closed IONet fanout to the Restricted IONet GMUG.

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Activities:

RIONET - Operations will switch from the Closed IONet to the Restricted
IONet before 06/26/2007.  On Tuesday 06/26/2007, the final string of
workstations (String 1) will be transitioned to the Restricted IONet.

Space Link Extension (SLE) - ACE SLE version 2.1 was delivered to the
Library on April 28, 2006.  Installation in the ACE MOC will not occur until
after the MOC is converted to the RIONET.

DSN/SPS/FDF - FDF continues to evaluate the ephemeris generation.  DSN SPS
always needs 8 weeks of predictive ephemeris.  With ACE's expanded HGA
constraint, ACE maneuvers can be spaced apart by more than 3 weeks.
Therefore, a 12 week predictive ephemeris will meet the DSN requirement.

Planning continues for integrating ACE operations into a multi-mission ops
center (MMOC).

Over the years, several problems with ACE clock calibration have been
resolved.  One last remaining problem is the signal travel time (aka range
delay) which is not incorporated into the calculation.  The result is that
all spacecraft time has been off by ~5 seconds.  Along with correcting this
problem, the entire life-of-mission clock calibration will be recalculated
to correct for all of the following errors:
	Range Delay not correctly accounted   launch-current
	DSN's Ground Receipt Time errors      2000-2003
	Leap seconds not correctly accounted  1999-2002
	Numerical error in calculation        launch-2006
The previous clock calibration resulted in discrepancies of up to 2 seconds.
The new clock calibration has a day boundary difference of less than 0.04
seconds.  We will coordinate with ASC to pick a day to start sending the
corrected range delayed clock calibration and implement the new life-of
mission calibration.  This correction will be implemented for the ACE MAG
data at 1-second time resolution.


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Anomalies:

DOY 162  06/11/2007  S-ACE-0192  G07-0049  TPOCC Error on AC2FE1A
The TPOCC ground software was generating the following error message while
performing block replay on the backup string.
	Data server received an unknown request - {unrecognizable number}
The software was restarted several times and the error message eventually
stopped.
IMPACT:  Minimal.  The backup string was being used for offline analysis of
the weekend attitude solution.  There was no impact to realtime operations.

DOY 162  06/11/2007  S-ACE-0191  G07-0050  DSS-54 Antenna Halt
The ground station antenna halted during tracking 1502-1512z.  Uplink was
re-established at 1514z.
IMPACT:  Playback data was redumped later in the pass.  As with all
telemetry outages, NOAA SEC did not receive ACE real-time data during this
time.

DOY 162  06/11/2007  S-ACE-0194  G07-0051  ROBOTT/C&C Failed to Resume
The automation ground software (ROBOTT/C&C) failed to resume after the 12
minute DSS-54 TLM/CMD outage 1514z.  No notifications were sent.  This is an
infrequent problem that last occurred 05/30/2006 (DOY 150 AR#G06-0059).  FOT
noticed the problem at 1631z and manually resumed ROBOTT.  CDSID#21191
IMPACT:  If ROBOTT had not been resumed, the daily state of health checks
and redumps would not have been performed.  C&C would not have sent
notifications about further TLM or CMD outages.  Necessary redumps would
have been performed on the following pass.  The ground procedures have been
written to reduce the impact if the automation software is unable to
complete the support.

DOY 162  06/11/2007  S-ACE-0195  G07-0052  Incomplete CDR download
The DSN CDR files for DOY 162 were downloaded to compensate for network data
loss during the pass.  The CDR file was not completely transferred from DSN.
The CDR file was downloaded a second time successfully.
IMPACT:  The incomplete CDR file was used for determining SSR redumps.  The
calculated dumplist would have played back 2 hours of data that had already
been dumped.  A corrected dumplist was created from the second successful
downloaded CDR file.