ACE Weekly 11/07/03 - 11/13/03
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).
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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)
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OCRs Executed:
DOY 03311 (11/07/03) EPAM-006 executed at 16:09Z & 19:00Z to power OFF and
then back ON the F and M subsystems.
DOY 03315 (11/11/03) SWPX-036 executed at 16:30Z & 17:15Z
=====================================================================
Ongoing Activities:
TAPS:
Release 4.1.10 was delivered on 11/06/03 and is currently being tested by
the FOT. The next delivery, Release 4.1.11, is scheduled for 11/18/03.
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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 03313 (11/09/2003) ACE Anomaly G03-0111 - GDS 34m (DSS-27) Antenna
Pointing Controller Problem
At 1550Z, DSS-27 informed ACE FOT that there will be a delay in
acquisition with the spacecraft due to antenna problems with no ETA as to
when the situation would be resolved. At 1642Z, DSS-27 acquired the
satellite and telemetry was first seen online by the ACE
FOT. IMPACT: Delayed pass activities for 47 minutes. All data
subsequently retrieved. DR# G103641
DOY 03317 (11/13/2003) ACE Anomaly G03-0112 - GDS 26m (DSS-16) Antenna
Y-Axis Failure
At 1510Z, DSS-16 reported their antenna was red (Y-Axis problem). At
1730Z, DSS-16 reported the antenna was ORANGE. At 1744Z, telemetry was put
online at the low (498 bps) data rate. IMPACT: Daily pass activities
delayed 2 hours. Unable to complete recorder dump due to the shortened
pass. All data subsequently retrieved on a later pass. DR# G103674
DOY 03317 (11/13/2003) ACE Anomaly G03-0113 - GDS 26m (DSS-16) TCP Halt
At 1744Z, DSS-16 put telemetry online. However, within 1 minute telemetry
dropped out. DSS-16 reported having problems with the TCP. At 1818Z,
DSS-16 put telemetry back online. At 1822Z, the transition was made from
low rate (498 bps) to high rate (87648 bps).
IMPACT: Delayed pass activities. All data subsequently retrieved on a
later pass. DR# G103675
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
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