ACE Weekly 11/14/2007 - 11/20/2007

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

The attitude maneuver was postponed from Thursday to Friday due to Anomaly
G07-0096.

	Type        Attitude
	Date        11/16/2007
	DOY         320 2007
	Thrusters   2R 4R+ 4R-
	Duration    11:45 min
	Start       13:14:40z
	Stop        13:26:25z
	HGAStart    -7.71deg
	HGAStop      6.54deg
	SunStart    15.67deg
	SunStop      5.74deg
	Nutation     0.30deg
	Firing      60 pulses
	FuelUsed      0.1988lbs
	FuelRemain  153.5604lbs
	FinalSCMass 1387.820lbs

The next attitude maneuver is scheduled for Tuesday, 11/27/2007.

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OCRs:

None

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Activities:

Space Link Extension (SLE) Testing status (F-CLTU)
The Friday 11/16/2007 DSS-46 test was successful.  The DSN Ground Receipt
Time problem has been resolved.

The FOT also tested the SLE feature where commands are transmitted at
specified times (aka Command Timing).  The DSN F-CLTU service worked
correctly, commands that were tagged for an hour in the future were not sent
until the prescribed time.  However, the FOT will keep this feature disabled
since it introduces a risk if the local workstation system time is not
correct.

The transition to F-CLTU SLE has been targeted for Thursday 11/29/2007.


34m HEF S-Band Transmitter Testing Status
The Thursday 11/15/2007 DSS-45 test was successful.  Telemetry was acquired
at all 3 bit rates.  The ACE MOC successfully binded and commanded to the
spacecraft.  And the GSFC Metric Tracking Data Evaluation (MTDE) group
received good Range and Doppler data.  The uplink signal strength measured
by the spacecraft was
	Hi-Gain Antenna   =  -99 dBm
	BroadBeam Antenna = -111 dBm
This signal strength is more than adequate and is comparable to DSS-27
(another 34m antenna with 200W transmitter).

No further DSS-45 tests are scheduled.  DSS-65 tests have been scheduled as
follows

	Date       DOY  Station   Test
	Mon 12/03  337  DSS-65    S-Band XMTR, SLE and range data
	Wed 12/05  339  DSS-65    S-Band XMTR, SLE and range data

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Anomalies:

DOY 316  11/12/2007  S-ACE-0242  S07-0010  S3DPU_I Limit Violation
S3DPU current (S3DPU_I) briefly violated the red high limit (RH > 145mA).
The S3DPU Idle Counter (SSDIDLECTR) was at 52.
	2007-316-21:59:36 - 21:59:37  150.528-153.664mA
IMPACT:  The last brief S3DPU_I violation was 2007-270-16:36:48.

DOY 318  11/14/2007  S-ACE-0243  G07-0095  DSS-27 Incorrect Bit Rate
At BOT, DSS-27 configured for high-rate data (87648bps), but the spacecraft
was still at low-rate data (498bps).  No telemetry was available and the MOC
automation software was waiting for telemetry before commanding the
spacecraft to high-rate.  The MOC contacted the station and asked that the
station configure for low-rate data which kicked off the MOC automation
software.
IMPACT:  The BOT bit rate change was changed from automatic (pre-loaded) to
manual (real-time cmd) as part of the 2004 transition to automation.  This
simplified the MOC automation, increased scheduling flexibility and reduced
outages to NOAA.  The consequence is that the DSN station must configure for
the 87648bps bit rate after the real-time commands are sent.  This problem
occurs 1-3 times each year.

DOY 318  11/14/2007  S-ACE-0244  G07-0096  Maneuver Planning HardDrive Fail
The hard drive for the maneuver planning PC failed on the day before an
attitude maneuver (DOY 319).  The FOT used a functionally minimal backup to
plan the maneuver, but nevertheless postponed the maneuver for a day.  The
SysAdmins recovered a significant portion of the hard drive and restored the
maneuver planning PC at the end of DOY 319.  The maneuver was planned with
the restored maneuver planning PC which gave the same results as the backup.
The maneuver was successfully executed on DOY 320 (Friday 11/16/2007).
IMPACT:  No angle constraints were violated by waiting an additional day
(HGA=-7.71deg Sun=15.67deg).  The same target was used for the maneuver and
no additional fuel was consumed.  All future maneuvers will be executed as
previously planned.

DOY 324  11/20/2007 S-ACE-0245  G07-0097  DSS-46 S-Band Exciter
Station was unable to obtain lock for a "Range Only" pass until the station
switched to SBE2.  Range data delayed 30 minutes.  Station continued uplink
for 30minutes after End Of Track (EOT)
IMPACT:  There are 5 other southern hemisphere range passes between the
attitude maneuver on 11/16/2007 and 11/27/2007.  Orbit Determination should
have sufficient range data.  And it would have been better if the station
terminated the uplink at the scheduled time.