ACE Weekly 04/02/04 - 04/08/04

All ACE spacecraft subsystems are performing nominally. An attitude 
maneuver was successfully  executed on 04/02/04. The next attitude maneuver 
is tentatively scheduled for 04/14/04.

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Orbit Events:

 From Craig Roberts (FDF):

The next ACE transit of the old Solar Exclusion Zone (SEZ) will run from 
05/19/04 to 06/14/04. For the first time ever, ACE will transit the solar 
disk on 06/01/04. On that date, the Sun's angular radius is 0.2629 degree 
(as seen from Earth's center). The solar transit will last nearly 21 hours 
(again, as seen from Earth's center). The main features of this transit are 
given in the following table (times are UTC).

5/19 01:42 4.75 deg inbound
5/27 07:45 2.0 deg inbound
5/30 23:39 0.63 deg inbound
6/01 01:18 0.2629 deg (kissing solar disk inbound)
6/01 10:46 0.197 deg (radius of closest approach to solar center)
6/01 22:14 0.2629 deg (kissing solar disk outbound)
6/02 23:28 0.63 deg outbound
6/06 11:15 2.0 deg outbound
6/14 07:18 4.75 deg outbound

The 0.63 deg epochs are included because that radius represents the closest 
approach during our last transit in February/March. ACE will spend almost 
exactly 3 days within this zone.

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OCRs Executed:

None

=====================================================================
Ongoing Activities:

TAPS:
- Transition from GTAS to TAPS occurred on 03/18/04. All trending 
activities are being accomplished using TAPS. No problems have been noted 
to date.

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Automation (ROBOTT):

- Testing of Release 0.5 is progressing well. This release will not be 
placed on String 1.
- Failover monitor/CRON testing began 03/19/04 with some minor problems 
identified.
- ROBOTT Release 0.6 is scheduled for installation on String 2 on 
04/09/04.  This release will not include any GTAS tasks and will include 
any fixed DRs at that time.

============================================================================
Extra Spacecraft Activities:

- Received final OCR from M. Popecki for the S3DPU Anti-Reset Patch 
activity. All loads have been built and reviewed by both M. Popecki and the 
FOT. SWICS/SWIMS OCRs for Latchup Recovery have been reviewed and finalized 
based on inputs from Jim Raines. Uploading of the Anti-Reset patch will 
occur on 04/09/04 with M. Popecki(SEPICA) and S. Lasley (SWICS/SWIMS) 
monitoring the activity.

=====================================================================
Anomalies:

DOY 04095 (04/04/04) ACE Anomaly G04-0025 - MAD 26m DSS-66 - X-Axis 
Hydraulics Failed
X-Axis Hydraulics on DSS-66 failed at 16:00.  Telemetry offline at 16:15 
for the rest of pass. IMPACT: Unable to complete pass 
activities.  Telemetry subsequently recovered on next day's pass.  DR# M102404

DOY 04095 (04/05/04) ACE Anomaly G04-0026 - MAD 26m DSS-66 - Station RED
At 13:30, the DSN Ops Chief informed the FOT that station DSS-66 was 
RED.  Station DSS-27 was able to provide coverage for the pass (BOT 14:45/ 
EOT 18:15).  IMPACT: None.  All pass activities completed.  DR# M102408
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Glen A. Miller
ACE Flight Operations Observatory Engineer
Honeywell Technology Solutions Inc.
Goddard Space Flight Center
Building 14, Room W10A
Mail Stop 428.2
Greenbelt, MD 20771

Office: 301-286-7071
Pager: 800-425-3174
Fax:    301-286-1729
gamiller@pop500.gsfc.nasa.gov
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~