ACE Weekly 09/02/05 - 09/08/05

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type         Attitude     Attitude
	Date         09/07/05     09/07/05
	DOY          250 2005     250 2005
	Thrusters    2R 4R+ 4R-   2R 4R+ 4R-
	Duration     4:46 min     6:52 min
	Start Time   17:12:27z    18:07:39z
	Stop Time    17:17:13z    18:14:31z
	Firing       25 pulses    35 pulses

The next attitude maneuver is scheduled for Friday 09/16/05.

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OCRs:

SWPX-040 is scheduled for Monday 09/12/05.  The SWEPAM-E CEM High Voltage
will be increased from level 14 to level 15 in order to compensate for
sensor gain losses due to aging affects.

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Ongoing Activities:

Space Link Extension (SLE) - The schedule for the next DSN/Developer test
with DTF-21 will be determined next week.

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Extra Activities:

DOY 249 (09/06/05) - TAPS release 4.4 was delivered and installed.  This
release resolved CDSID#21044 (incorrect data decommutation in ADC) but
does not fix CDSID#21043 (1-second data gaps every 429 seconds).


DOY 250 (09/07/05) - A 1-hour (2035-2135z) Project Interface Test (PIT)
was completed for the equipment upgrade at DSS-27 (V5.9).  We were
informed that DSN's current setup does not correctly account for
ground delays when generating the range data which causes an error of
approximately 150 nanoseconds.  DSN expects to have new software to
correct the problem in January 2005.  Also, during the test, DSS-27
stopped tracking after conscan was enabled (DR G106037).  Further post-pass
data analysis is underway.


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Anomalies:

DOY 247 (09/04/05) ACE Anomaly G05-0110  26m DSS-16 Antenna Pointing
Problems
Problems with the Metric Pointing Assembly (MPA) at Beginning Of Track (BOT)
were resolved by the ground station with an equipment reboot.  DR G106025
IMPACT:  Activities delay 16 minutes.


DOY 248 (09/05/05) ACE Anomaly G05-0111  ROBOTT/CC Failure Not Cleared
ROBOTT generated a "Task Verification Failed" message due to a known problem
(CDSID 21261).  However, the failure was not cleared until later in the pass
when a second procedure was being executed.
IMPACT:  Troubleshooting completed to ensure that the second procedure
did not have failures.


DOY 237 (08/25/05) ACE Anomaly G05-0112  26m 0158 TCP Data Unavailable
Post pass analysis of the LMP PIT (DOY 237) shows that DSN's 0158 Monitor
Data only provides data for 1 TCP.  The station switches TCPs for each
bit rate change.  When the other TCP is used, the 0158 still gives data
for the first TCP.  Analysis of previous data shows that this problem has
been occurring before the new LMP.
IMPACT:  Monitor data (including ground SNR) unavailable for trending
and anomaly trouble-shooting.


DOY 250 (09/07/05) ACE Anomaly S05-0036  S3DPU Limit Violations
S3DPU_CONV_SEC_I had 1 brief red high limit violation (>440mA).
SSDIDLECTR was 60-67.  Increased solar activity started on DOY 250.
Mark Popecki notified.
	2005-250 16:22:30 - 16:22:32z		462 - 470mA
IMPACT:  S3DPU is expected to use more current during increased
activity.


DOY 250 (09/07/05) ACE Anomaly G05-0113  26m DSS-16 Ranging Cals
Station unable to perform pre pass range cals due to problems
with enabling pre pass ranging signals.  DR G106033
IMPACT:  Post pass range cals performed at the end of the support.


DOY 250 (09/07/05) ACE Anomaly G05-0014  26m DSS-16 Signal Acquisition
Station unable to acquire spacecraft downlink after earlier problems
with pre pass range cals.  DR G106034
IMPACT:  Activities delayed 30 minutes.  Gaps in playback data
captured on DOY 251.


DOY 250 (09/07/05) ACE Anomaly G05-0015  26m DSS-16 CMD Mod Index
Station's CMD MIL changed during the troubleshooting of earlier
downlink acquisition problems.  Station unable to change value
during support.  Post pass analysis indicated a CMD Mod Index
of 1.74rad/8.52dB as compared to the nominal value of
0.86rad/1.69dB.  DR G106036
IMPACT:  Uplink to spacecraft reduced with increased CMD Mod Index