ACE Weekly 10/24/2007 - 10/30/2007

All ACE spacecraft subsystems are performing nominally.

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

	Type        Attitude
	Date        10/29/2007
	DOY         302 2007
	Thrusters   2R 4R+ 4R-
	Duration    14:19 min
	Start       15:27:49z
	Stop        15:42:08z
	HGAStart    -6.90deg
	HGAStop     +7.25deg
	SunStart    12.70deg
	SunStop      5.85deg
	Nutation     0.44deg
	Firing      73 pulses
	FuelUsed      0.2381lbs
	FuelRemain  153.7592lbs
	FinalSCMass 1388.019lbs

The next attitude maneuver is scheduled for Thursday, 11/15/2007.

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

DOY 303 (10/30/2007)  OCR GND-189  Recalculate Clock Calibration
Over the years, several problems have been corrected in the clock
calibration calculation (leap seconds, bad ground receipt time, numerical
error, incorrect epoch, etc.)  ASC had adjusted several solutions while the
problems were being resolved.

This OCR uses the updated clock calibration software delivered 12/05/2006
(OCR GND-174) to recalculate the clock calibration for the entire life of
the mission.  These updated values are not expected to deviate from the ASC
adjusted values by more than 1 second.

Note that this recalculation does not incorporate the range delay as decided
by the instrument teams at the Science Working Team meeting (October 2007).
All timestamps (maneuvers, limit violations, etc) correspond to the Ground
Receive Time (aka Earth Receive Time).  The actual spacecraft events occur
approximately 5 seconds before the time given due to the light travel time
(aka range delay).

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

Space Link Extension (SLE) Testing status (F-CLTU)
Wed  10/24  297  DSS-46  DSS-46 was RED due to X Axis brake failure
Thu  10/25  298  DSS-34  Success with CMD and receiving low and medium TLM
Mon  10/29  302  DSS-46  Several problems were encountered with this test
* Unable to bind and no telemetry available due to problems with the Monitor
  Control Processor (MCP1).  Station rebooted MCP, reloaded the desktop and
  reconfigured for the SLE test support.  The MOC finally received
telemetry.
* The MOC was still unable to bind.  The station reset the Telemetry Control
  Processor (TCP) system clock which was running 5 seconds fast.  The MOC
was
  finally able to bind.
* The MOC was still unable to command.  The station halted the command state
  and returned to Operate mode which then allowed successful commanding.
* The MOC commanded to high-rate, but did not receive VC2 data.  The station
  had to unload the desktop and reconfigure.

DSN will continue to reconfigure the ACE 26m desktops.  The desktops had
already been updated to resolve a previous problem of not discarding
uncorrectable data.  DSN will review their procedures concerning resetting
the TCP clock and/or widening the command time constraint.

The following tests have been scheduled for upcoming weeks
	Day  Date   DOY  Station
	Thu  11/01  305  DSS-66 with DSS-27
	Thu  11/01  305  DSS-27
	Mon  11/05  309  DSS-24
	Wed  11/07  311  DSS-46


DSS-45 (34m HEF, Canberra) has had an S-Band Transmitter installed.  After
testing DSS-45, ACE will start using it along with the currently used DSN
stations (24, 27, 34, 46, 54, 66).  The DSS-45 tests have been scheduled for
Monday 11/12/2007 and Thursday 11/15/2007.  DSS-65 (34m HEF, Madrid) will
also have a new S-Band Transmitter and will be tested in December.

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

DOY 297  10/24/2007  S-ACE-0240  G07-0093  DSS-66  TLM/CMD Outage
DSS-66 uplink and downlink signal strength started decreasing at 150900z.
Signal strength returned to nominal at 151030z.  A command transmitted at
150930z was retransmitted.
IMPACT:  Minimal.  Brief 1 minute telemetry outage and the spacecraft's RCVR
B lost lock on the uplink.

DOY 298  10/24/2007  S-ACE-0241  G07-0094  ROBOTT/C&C Start 2 Procs
ROBOTT/C&C started 2 procedures without waiting for the other to complete;
G_END_DAY (19:10:01) and S_OPS_PLBK_COMPLETE (19:10:11).  The spacecraft was
commanded to BinDump format when SSR redumps were started.
IMPACT:  The automation software sent commands to the spacecraft in an
unexpected order.  Fortunately, the STOL procedures successfully handled the
unexpected spacecraft configuration.  Several contingency situations have
been incorporated into procedures.