ACE Weekly Report: 12-27-00

All ACE spacecraft subsystems are performing nominally. An attitude
maneuver was successfully executed on 12-21-00.  The next scheduled
attitude maneuver is scheduled for 12-28-00.

A station keeping maneuver (SK-18) along with an attitude maneuver is
scheduled for 01-04-01. The station keeping burn will be fairly modest in
magnitude, with fuel usage likely to fall in the 0.10 to 0.15 kg range. No
instrument voltage ramp downs will be required.

12/21 Maneuver:
Maneuver 1 Start Time=17:56:43 Maneuver 1 End Time=18:04:05
Pre-Maneuver HGA = -4.0858 deg. Sun Angle = 4.2969 deg.
Post-Maneuver HGA = 4.5 deg. Sun Angle = 12.9497 deg.
Current S/C range: 1,514871.118 km

12/21:
The ACE FOT performed preliminary tests with DSN's Uplink Command system
(UPL) in loopback mode (no uplink to the spacecraft) with Goldstone Station
D24.
RESULT:
ACE GDS Test of the UPL Command System at DSS-24 was unsuccessful due to
the inability to communicate with the Command Control Processor (CMP).
Follow-up of this problem will be done and a retest will be scheduled at a
later date.

12/23:
At AOS (13:03:08), RCVR_A_AGC levels were fluctuating beyond the yellow low
limit. AGC levels stabilized at ~13:20:00. During the pass AGC levels (both
DSN and S/C) were decreasing. At ~15:25:00, higher AGC levels returned. 2
minutes of playback data was lost and replayed during s_ops_plbk_complete.
All data was recovered.

12/24:
NOAA (Boulder, CO) did not receive data from NASA for beginning of
track.  Analyses by IP/NOCC indicated no ACE/NOAA ISIS processes.  Problem
was corrected and data began flowing to NOAA.

12/25:
During the weekly SWEPAM instrument Calibrations SWEPAM-E accepted the
command to proceed into "cal" mode. However, the FOT procedure never saw
the instrument go into that mode.  The command to calibrate the Electron
component likely arrived at the "end of a cycle" and the instrument
executed the command immediately rather than putting it into the queue as
would be the case normally. As a result, the mnemonic swpe_pendcycle never
took on a value of "cal", and thus stalled at the point in the procedure
where it waits for this to occur.

ACE FOT contacted SWEPAM instrument representative.  The procedure was
re-executed with desired results.  There was no science or operational
impact to the instrument.