ACE Weekly 04/16/04 - 04/22/04

All ACE spacecraft subsystems are performing nominally. No attitude 
maneuvers were executed this reporting period. The next attitude maneuver 
is scheduled for 04/27/04.

============================================================================
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.

=====================================================================
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.

----------------------------------------------------------------------------
Automation (ROBOTT):

- Release 0.6 installed on String 2 on 04/09/04.
- FOT testing is almost completed.
   -- 3 DRs left to verify - two for CRON dealing with pass schedules, one 
for C&C for the background monitors.  Two new DRs have been generated.
   -- 21 DRs have passed verification.
   -- 1 DR (color allocation) still needs some work.  There are no color 
issues if C&C is brought up by CRON or the Start Real-Time button.  If C&C 
is brought up with the individual button, there still maybe some color 
issues, but these do not occur every day.
- Installation of the latest release to String 1 is tentatively planned for 
the week of May 3rd.  The date is highly dependent on the FOT's testing 
progress.
- SUG development is ongoing.  Tentative release date is the end of May.  A 
DRAFT version may be available prior to that.

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

- Executed the S3DPU Anti-Reset Patch activity with Mark Popecki (SEPICA) 
and Scott Lasley (SWICS/SWIMS) monitoring. To date there have been no 
problems encountered with the new patch.  Mark Popecki continues to monitor 
S3DPU activity.  SWICS and SWIMS should return to NORMAL operations around 
04/23/04.

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

DOY 04111 (04/20/04) ACE Anomaly G04-0028 GDS 26m (DSS-16) VC2 Data Hits - 
Dropped Blocks
At 16:40:32, DSS-16 put telemetry online.  Immediately, the ACE FOT noticed 
VC2 data hits.  At 16:48, the FOT informed DSS-16 of the problem.  At 
16:51, JPL COMM was informed of the situation and stated they would check 
into the problem.  At 16:57, JPL COMM confirmed seeing dropped blocks.  The 
problem continued throughout much of the pass.  At 18:16, the VC2 data hits 
ceased and telemetry was clean from that point. IMPACT:  Degraded data 
throughout most of the pass.  Data recovered via CDR file.  DR# N102085

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~