ACE Weekly 11/14/03 - 11/20/03
All ACE spacecraft subsystems are performing nominally. No attitude
maneuvers were executed this reporting period. The next
stationkeeping/attitude maneuver is scheduled for 11/21/03 (See Orbit Events).
============================================================================
Orbit Events:
(From Craig Roberts, FDF)
ACE stationkeeping maneuver (SK-30) is scheduled to coincide with the next
attitude maneuver on 11/21/03. This will be our first SK burn since
6/23/03. The delta-V will be of relatively modest size at approximately 33
cm/sec. A delta-V of this size implies a continuous burn time of about 57
seconds, and would consume roughly 0.223 lbm (0.101 kg) of fuel. The
anti-Sunward direction of this delta-V will require the top deck jets 1A
and 2A.
A few days after SK-30, the next SEZ transit will begin. Its particulars
remain basically the same as previously given. Closest angular approach to
the Sun will be approximately 0.58 degree closer than the September
transit, which was 1.76 deg. To summarize the 24-day transit by epoch and
SEV angle:
26 Nov 20:56Z 4.75 deg (inbound)
5 Dec 01:22Z 2.0 deg
8 Dec 18:17Z 1.19 deg (minimum)
12 Dec 19:27Z 2.0 deg
20 Dec 22:00Z 4.75 deg (outbound)
=====================================================================
OCRs Executed:
None.
=====================================================================
Ongoing Activities:
TAPS:
Release 4.1.11 was delivered on 11/19/03 and is currently being tested by
the FOT. The SUG is currently being reviewed by the FOT and SGT.
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Automation (ROBOTT):
- ROBOTT version 0.2 (Offline) is operational on String 1.
- ROBOTT Version 0.3 was installed on String 2 (11/05/03) following the FOT
verification of fixed Offline and HSM DRs on String 3. The FOT is currently
testing the release on String 2.
- Command & Control is still being tested by the Automation team and the FOT.
- The first draft of the SUG is expected soon.
=====================================================================
Anomalies:
DOY 03318 (11/14/2003) ACE Anomaly G03-0115 - TPOCC Error Message -
Received a message that "snap error ace_cmdstat terminated prematurely",
while running G_END_DAY. IMPACT: None. The cmd_stat page printed nominally.
DOY 03321 (11/17/2003) ACE Anomaly G03-0116 - GDS 34m (DSS-27) Transmitter
Problems
At 16:12:04, DSS-27 informed ACE FOT that they were having transmitter
problems, a technician was sent out to the site, and they should be up
momentarily. Telemetry online at 16:24:25 but no command
capability. Command capability established at 16:44:27. IMPACT: Delayed
pass activities. All telemetry was subsequently recovered. DR# G103696
DOY 03324 (11/20/2003) ACE Anomaly G03-0117 - GDS 34m (DSS-27) Transmitter
Problems
At 15:40, DSS-27 informed the FOT that there were problems with the
transmitter. No ETA was given as to when the problem would be
fixed. Obtained a Short Tracking Pass with Station 46 from 1950 (BOT) to
2125 (EOT). IMPACT: No pass activities were performed during the
scheduled Station 27 pass. DR# G103722
DOY 03324 (11/20/2003) ACE Anomaly G03-0118 - GDS 34m (DSS-27) No Telemetry
Online
Telemetry was not online from DSS-27 until 17:55. At the beginning of the
pass, DSS-27 had data type 78 online but the MOC didn't see any coming into
the system. After troubleshooting both JPL and NASA networks DSS-27
switched to data type 78 and the MOC finally received telemetry. No
command capability because of the concurrent transmitter
problem. IMPACT: No pass activities were performed during the scheduled
Station 27 pass. All telemetry recovered on later passes. DR # N101618
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~