ACE Weekly 08/08/03 - 08/14/03

All ACE spacecraft subsystems are performing nominally.  No maneuvers were 
executed this week. The next attitude maneuver is scheduled for 08/18/03.

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Orbit Events:

The next SEV transit will occur during the 09/01/03 - 09/23/03 time frame. 
Expected minimum SEV angle will be 1.76 degrees.

The essential timeline based on a 30-min step scan for this 22 day, 8.5 
hour event is:
- SEZ entry (4.75 deg inbound) on Sept. 1 at 0100Z
- Minimum Sun-Earth-ACE angle = 1.760 deg on Sept. 12 at 0800Z
- SEZ exit (4.75 deg outbound) on Sept. 23 at 0930Z

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OCRs Executed:

Day 03226 (08/14/03) - OCR# SC_03_001 - Blind Commanding of SSR Dump
DSN problems for two consecutive days has raised the possibility for data 
loss. CDR file from yesterday's support showed good data capture by 
DSN.   While DSN time is available late today, there still may be possible 
data loss.  Starting the dump (& verifying it via CDR replay) will possibly 
minimize data loss and the amount of DSN time needed later.

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Ongoing Activities:

TAPS:
Trending, Analysis and Plotting System (TAPS) development continues with 
emphasis being placed on fixing the DRs attributed to prior releases. 
Release 4.1.6 was installed successfully on 08/05/03 and is currently in 
test by FOT.

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Automation (ROBOTT):
  - ROBOTT Release 0.2 was installed on String 2 on 08/13/03.   Since the 
install, the FOT has been testing at the individual button level with one 
minor environment problem.
  - HSM testing continues on String 3.
  - No progress on Command & Control, delivery date to FOT is still TBD.

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

DOY 03224 (08/12/2003) - ACE Anomaly G03-0074 -  GDS 26m (DSS-16) Command 
Not Getting to Spacecraft
The first command sent didn't reach spacecraft; DSS-16 said the command was 
leaving the station however the FOT saw no indication on board the SC that 
the command had been received.  DSS-16 rebooted TCP1.  FOT referenced
AR G03-0064 and suggested to station to reset the command mod 
index.   DSS-16 manually reset the command mod index to the wrong 
values.  Further attempts to command were only partially 
successful.   DSS-16 configured the command mod index to the correct value 
and commanding resumed with no further problems.  IMPACT:  Delayed pass 
activities 40 minutes.  DR G103183

DOY 03224 (08/12/2003) ACE Anomaly G03-0075 - GDS 26m (DSS-16) TCP Halt
At 15:06:59 telemetry went offline. DSS-16 informed FOT that TCP1 halted 
and needed a reboot. After the reboot the telemetry came back online. 
IMPACT:  None.  All data was acquired.  DR# G103184

DOY 03225 (08/13/2003) ACE Anomaly G03-0077 - GDS 26m (DSS-16) Reliable 
Network Server (RNS) Problems
FOT gave prepass briefing to station;  DSS-16 informed FOT that they were 
having RNS problems (Goldstone Complex Wide) with No ETA on when the RNS 
would be fixed.  Telemetry dropouts occurred throughout pass.  Commanding 
problems as well with continued drops in telemetry.  Problems with RNS 
continued on DSS-27 on DOY 03226.  IMPACT:  Unable to dump recorders, 
however the data was retrieved at a later date.  Because of this problem 
with the RNS and the inability to confirm command receipt via telemetry, a 
reconfiguration of the SC RF subsystem would occur and will be documented 
at a later date (see AR S03-0017).  DR#s G103191, G103203

DOY 03226 (08/14/2003) ACE Anomaly S03-0017 - RF Watchdog Timer Expired
AT 16:09:27  XPNDR B-RF Watchdog triggered which caused the XPNDR B to 
reconfigure to the broadbeam antennas on the top deck and enabled the 
XPNDR_HTR relay.  Antennas successfully reconfigured on DOY 03227 at 
22:00:05.   IMPACT:  Additional contacts required to reconfigure antennas 
to nominal configuration.

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