ACE Weekly Report (03/28/02  04/04/02)

All ACE spacecraft subsystems are performing nominally.  Attitude
maneuvers were successfully performed on 03/28/02 and 04/04/02.  The
next attitude maneuver is scheduled for 04/11/02.

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 using the 4.5 degree constraint as the target.
On 03/28/02 the spacecraft HGA reached ~4.83 degrees prior to the
attitude maneuver.  The spacecraft drifted to ~4.8 degrees again on
04/04/02 prior to the maneuver.  Analysis is ongoing, though no
degradation in signal strength has been seen.  The 04/11/02 support has
been shifted to later in the day to allow for the spacecraft to drift
even further.  The HGA will reach ~5.29 degrees before the attitude
maneuver on 04/11/02.

Anomalies:
03/29/02  DOY 088 AR# G02-0035 Exciter problems with Station D16 at
start of support. Unable to support the ACE pass.  Support transitioned
to Station D27.  (DR# G100937).

04/01/02  DOY 091 AR# G02-0036 MOC experienced command problems at start
of support.  Station D27 notified.  CPAs eventually swapped and no
further problems experienced during the support (DR #G100944).

04/03/02  DOY 092 AR# G02-0037 MOC experienced ~7 minute telemetry
dropout.  Station D16 notified; advised FOT that they were having
problems with their SCP and were in the process of troublshooting that
system.  Problem resolved and telemetry back online.  All affected SSR
data was redumped during the support (DR #G100951).

04/03/02  DOY 092 AR# G02-0038 MOC experienced ~18 minute telemetry
dropout.  Station D16 notified;  TGCs swapped.  All affected SSR data
was redumped during the support (DR #G100954).