ACE Weekly Report 03-20-02

All ACE spacecraft subsystems are performing nominally.  Attitude
maneuvers were successfully performed on 03/14/02 and 03/19/02.  The
next attitude maneuvers are scheduled for 03/22/02 and 03/28/02.

The FDF proposal to widen the HGA constraint to 6 degrees has been
verbally approved.  The FOT is awaiting documented Project approval.
The current HGA constraint is 4.5 degrees.  The constraint will be
increased in several steps, over the next four 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 week of April 1st.  The maneuver performed on 03/28/02
will use the 4.5 degree constraint.  The plan is to allow the spacecraft
to then drift until the new 5.5 constraint would be violated and then
perform an attitude maneuver.  The new HGA constraint would be kept at
5.5 degrees for several weeks, to allow for analysis prior to continuing
with the next step.  NOAA has been notified of the planned increase of
the HGA constraint and will analyze any impact to their data.  The FOT
has developed several procedures and scripts which will be used to
recover from an anomaly resulting from the increased HGA, if one were to
occur.

FORMATS 2001.01D1 string 2 installation scheduled for March 25, 2002.

Anomalies:
03/17/02  DOY 076 AR# G02-0031 Severely degraded telemetry experienced
throughout D27 support.  Numerous SSR redumps performed.  Insufficient
time to recover all affected SSR data.  Postpass analysis showed
behavior consistent with December 2001 anomalous D27 supports.  The ACE
NOPE has been notified and is investigating.  Next D27 support is
scheduled for DOY 082.