ACE Weekly Report (04/12/02  04/18/02)

All ACE spacecraft subsystems are performing nominally.  Two attitude
maneuver were successfully performed on 04/18/02.  The next attitude
maneuver is scheduled for 04/26/02.

OCR SEPICA-100 was executed on 04/12/02 to reduce 30kV from 4kV to 0kV.

OCRs ULEIS-029 and ULEIS-030 were executed on 04/15/02.  The TOF system
had stopped working in April 2000.  The instrument team periodically
checks the system to see if it now works.  The voltage was raised and
the system monitored.  The TOF system still is not functioning.  The
voltage was returned to its original state.

Active C&DH block bins were dumped on 04/16/02.  No miscompares were
found.

Support on 04/18/02 extended 30 minutes to allow for the completion of
all maneuver activities.  Support had been interrupted for ~15 minutes
by fire alarm.

An engineering test is in progress to determine a new HGA constraint.
The current constraint is 4.5 degrees.  The constraint will be increased
in several steps, over the next three months with the maximum constraint
being reached by late June, when the spacecraft will be at its maximum
range.  The first and largest step will be an increase to 5.5 degrees.
The approach used will be to allow the spacecraft to drift until the new
constraint would be violated.  An attitude maneuver would then be
executed.

Date:  HGA reached prior to Attitude Maneuver (degrees):
03/28/02    ~4.8
04/04/02    ~4.8
04/11/01    ~5.1
04/18/02    ~5.2
04/26/02    ~5.5

Analysis is ongoing, though no degradation in signal strength has been
seen.

Anomalies:
04/13/02  DOY 103 Station D27 declared red; unable to support ACE pass.
The pass was moved from D27 to D46.  Insufficient time during the
support to complete SSR playback activities.  All data captured during
the following support (DR#G101008).

04/17/02  DOY 107 MOC experienced ~14 minute telemetry dropout due to
problems with DSNs Complex Supervisor/TSP computers.  Station
notified.  All affected SSR data was redumped during the support (DR#
G101036).