ACE Weekly Report: 06-27-01

All ACE spacecraft subsystems are performing nominally. An attitude
maneuver was successfully performed on 06-22-01. The next attitude maneuver
is scheduled for 06-28-01.

Instrument Commanding
6/25  SWEPAM Weekly Calibrations performed

6/22  ULEIS-054 (shutter diagnostic #12)
Diagnostics performed to focus on the fiducial's LED and photo transistor
settings and the possibility that electrical noise that occurs when
stepping the motor is causing erroneous fiducial readings.

6/26 ULEIS-055 (shutter diagnostic #13)
Delay inserted between the moving of the motor and the reading of the
fiducial value in order to avoid any noise induced in the photo transistor
lines by the motor drive circuitry.

6/26 SEP-087 (Steps 5-6)
30kV set point increased to 2.6kV and alarm limits set to 140dec for S3DPU
monitoring.  This commanding is part recovery from the recent 30kV reset
and ongoing investigation of the 30kV supply anomaly.  Science data is not
being collected from SEPICA instrument.

6/27 ULEIS-056 (shutter diagnostic #14)
Slight adjustments to fiducial table made in order to achieve better
centering in the middle of the 25% and 1% position fiducials


Ground Operations:

Anomalies
6/22  (AR# G01-0047 DSN Station 66 Madrid)
At BOT sta 66 had two pieces of equipment fail . Fwd link CPA and return
link TGC.  Station 66 swapped out both pieces of H/W and nominal support
operations resumed.  Two DSN DRs were generated - M1000-13 for the CPA and
M1000-14 for the TGC.  No impact to operations

Off-line

6/26  OCR-039 performed for 3QFY01 GITT security scan to identify security
vulnerability on ACE strings.

Dave Myers
Honeywell Technology Solutions Inc.
Advanced Compostion Explorer (ACE)
System Eng/Mission Planner
w 301-286-7014