ACE Weekly Report (05/10/02  05/16/02)

All ACE spacecraft subsystems are performing nominally. No maneuvers were 
executed during this reporting period.  The next attitude maneuver is 
scheduled for 05/17/02.

The 34m UPL Demo Pass with DSS-54 was held on DOY 136, May 16, 2002.  This 
pass was scheduled to verify the new 34m UPL D2 command system.  No 
problems were encountered during the pass.  Successful demo pass.

An engineering test is in progress to determine a new HGA constraint. The 
current constraint is 5.5 degrees, however the FOT has been given 
authorization to drift to as much as 6.0 degrees prior to maneuvers. The 
constraint was increased on 26 April, as part of a several step process 
that will occur over the next two months with the maximum constraint being 
reached by late June, when the spacecraft will be at its maximum 
range.  This approach allows the spacecraft to drift until the new 
constraint is violated, at which time an attitude maneuver is executed.

Date: HGA angle 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 ~5.6
05/06/02 ~5.8
05/17/02 ~5.9 (expected)

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

Anomalies:
05/10/02 DOY 130 - ACE Anomaly #G02-0057  Two minute drop in signal 
(1728-1730).  Minimal impact to telemetry received.  D16 investigated the 
problem and said it was possibly outside interference.

05/15/02 DOY 135  Late AOS due to bad Telemetry Processor.  DSS-16 swapped 
out TGC.  All data recovered.  (DR#G101152)