ACE Weekly 10/24/03 - 10/30/03

All ACE spacecraft subsystems are performing nominally. An attitude 
maneuver was successfully executed on 10/24/03.  The next attitude maneuver 
is scheduled for 11/06/03.

Recent solar activity has had some effect on the ACE spacecraft.  Normally 
the ACE Spacecraft experiences a 2% drop in solar array output over a 
year's time, however the recent solar activity has dropped the solar array 
output an additional 1% in one week's time.  (This is an expected result 
based on past experience with increased solar activity.)  The ACE 
spacecraft utilizes only 50% of the solar array power available so this 1% 
degradation is negligible.   In addition some instruments are experiencing 
some limit violations and increased activity.  The FOT is monitoring all 
instruments and notifying instrumenters of any and all unexpected events.

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Orbit Events:

The next SEV transit will occur November 26th through December 20th. The 
minimum SEV angle expected will be approximately 1.19 degrees.

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OCRs Executed:

OCR SWPX-036 was scheduled for execution on DOY 03301 (10/28/03) but was 
delayed by Jim Griffee because of the solar activity.  It is now scheduled 
for execution on DOY 03308 (11/04/03).


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Ongoing Activities:

TAPS:
The FOT is currently testing Release 4.1.8 to ensure all DRs flagged as 
"essential to transition" have been fixed.  The next release 4.1.9 is 
schedule for delivery on 11/04/03.

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Automation (ROBOTT):

- ROBOTT version 0.2 (Offline) is operational on String 1.
- The next release of Offline and HSM has been pushed back to November 5th 
to allow for more DRs to be included in the release and to allow for 
further testing of those DR fixes on String 3.
- Command & Control is still being tested by the Automation team with not 
much progress due to WIND/POLAR having some problems this week.
- The first draft of the SUG is expected soon.

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Anomalies:

DOY 03297 (10/24/2003) ACE Anomaly G03-0107 -  GDS 26m (DSS-16) - Command 
Not Reaching Spacecraft
ACE FOT noticed that the first command did not make it to the spacecraft, 
but were receiving command echoes from CPA; Notified DSS-16 to monitor 
commands on their end.  ACE FOT resent first command; no success. ACE FOT 
verified command mod index of 0.86 with DSS-16.  ACE FOT requested that 
DSS-16 manually reset the command modulation index to 0.86.   ACE FOT 
resumed commanding and all  commands made it to the 
spacecraft.   IMPACT:  Delayed pass activities for ~12 minutes.   DR# G103565

DOY 03297 (10/24/2003) ACE Anomaly S03-0022 -  Mnemonic S3DPU_CONV_SEC_I 
Limit Violation
The mnemonic, S3DPU_CONV_SEC_I, violated its red high limit twenty times 
during the pass. Due to the length of the dog-leg maneuver, the S3DPU Idle 
Counter was not monitored. However, after the pass on DOY 298, all the data 
will be obtained for the S3DPU Idle Counter and S3DPU_CONV_SEC_I and passed 
on to Mark Popecki.   M. Popecki responded that this was probably related 
to data processing due to the increased solar activity.  Impacts:  Unknown 
at this time.  FOT to continue monitoring.

DOY 03301 (10/28/2003) ACE Anomaly G03-0108 - GDS 26m (DSS-16) - TCP Halt
DSS-16 notified FOT that the TCP required a reboot. Telemetry was offline 
from 15:57:08 to 16:00:10. IMPACT:  Delayed pass activities.  All data 
subsequently recovered.  DR# G103580

DOY 03301 (10/28/2003) ACE Anomaly S03-0023 - Mnemonic STAR_FA_CNT Limit 
Violation.
The mnemonic STAR_FA_CNT (star false alarm count) violated the red high 
limit of 128, 10 times throughout the pass.  IMPACT:  Unknown.  There was 
severe solar activity at this time, but it is not known if this is what 
caused the violations.  FOT still investigating.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
Email: gamiller@pop500.gsfc.nasa.gov
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~