ACE Weekly 08/13/04 - 08/19/04

All ACE spacecraft subsystems are performing nominally.  No attitude 
maneuver was executed this reporting period.  The next stationkeeping 
/attitude maneuver is scheduled for 08/20/04.

============================================================================
Orbit Events:

 From Craig Roberts (FDF):
The next ACE stationkeeping maneuver (SK-33) is scheduled for 08/20/04, to 
coincide with a scheduled attitude reorientation maneuver.  Thus SK-33 will 
be out of the way just as the next SEZ transit--which will have its closest 
approach to the Sun on 08/30/04 --is beginning.  The delta-V for 08/20/04 
is currently projected to be about 0.37 m/sec in the anti-Sunward 
direction.  The burn duration is estimated at 64 seconds.

ACE's Lissajous orbit has now transitioned to an opening pattern, so the 
ACE motion will now be counterclockwise about L1 (and for that matter, the 
Sun) for quite a long time to come.

=====================================================================
OCRs Executed:

None

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

TAPS:
- Installation of TAPS release 4.3 is occurred on 07/20/04.  FOT testing of 
this release is ongoing.
   -- Of the 6 DRs fixed in release 4.3, 5 have been verified, 1 has failed.

- Additional DRs will be submitted for newly found problems.

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

- ROBOTT v0.7 has been used for daily operations on String 1 since Tuesday 
07/27/2004 (OCR GND-140) with ROBOTT in Advisory and Auto modes.  No data 
loss or command problems due to ROBOTT have occurred this week.

- ROBOTT v0.8 was installed on Strings 2 and 3 on 08/12/04 (OCR GND_141).  The
installation on both strings facilitates testing the RTMON component.
Out of 25 DRs, 14 have been verified, 2 have failed, and the rest will have 
to be tested with v0.81.

- ROBOTT v0.81 is scheduled for installation on Strings 2 and 3 on 08/20/04 
(OCR GND_142) after the stationkeeping/attitude maneuver.  This version 
contains a patch to C&C based on the discrepancies found during testing of 
v0.8.

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

None

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

DOY 04228 (08/15/04) ACE Anomaly G04-0096 - ROBOTT - C&C Did Not Add MC 
Privileges
At 12:13:01.2  C&C issued: ACC ADD MC;  FOT noticed that the MC privileges 
were not added to C&C.  IMPACT: FOT intervention was required to allow C&C 
to run for the entire pass.
If FOT had not intervened C&C would have not ran G_ACE_UP or any other 
procedure.

DOY 04229 (08/16/04) ACE Anomaly G04-0097 - GDS 26m (DSS-16) Telemetry Outage
At 15:12:34, telemetry was lost from DSS-16.  Telemetry resumed at 
15:14:36.  IMPACT:  None.  Data retrieved from SSR playback and CDR file.

DOY 04229 (08/16/04) ACE Anomaly G04-0098 - ROBOTT - C&C Froze
At 15:17, after a 2 minute telemetry outage, C&C attempted to resume itself 
without the forward link enabled.  However, DSS-16 lost lock on the 
spacecraft receivers.  C&C froze and minutes later at 15:27:55, the C&C 
flag (CF=5) was set to 5.  At 15:33:42, the pop-up box was received that 
stated, "Failover (Reboot) In Progress".  At 15:35:50, after the reboot, 
C&C started coming up before TPOCC.  This caused the FOT to receive another 
pop-up box that stated, "Failover (String) In Progress.  The failover was 
set to remain on string 1.  Everything came back up without any 
problems.  However, it was noticed that CRON was killed at 11:34:09 and not 
restarted.  Again at 11:51:40 Cron was killed and not 
restarted.  IMPACT:  Loss of command capability.  CRON was killed and not 
restarted (known DR).  All telemetry retrieved via playback and CDR.


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