ACE Weekly 11/26/04 - 12/02/04
All ACE spacecraft subsystems are performing nominally. No maneuvers were=
=20
executed this reporting period. The next maneuver (Stationkeeping and=20
Attitude) is scheduled for 12/06/04.
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Orbit Events:
The ACE Solar Exclusion Zone (SEZ) transit is nearing an end. ACE crossed=
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the 4.75 deg mark inbound on 11/15/04, and will exit outbound by=20
12/09/04. The angular radius of closest approach (RCA) was 0.83 degrees on=
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11/26/04. No problems with the downlink to date.
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From Manuel Montoro (FDF):
There is an ACE stationkeeping maneuver (SK-34) scheduled for=20
12/06/04. Preliminarily, it looks as follows:
--delta-V =3D 0.3159 m/s
--burn duration =3D 57.606 sec
--fuel usage =3D 0.2184 lbm (0.099 kg)
The delta-V is Sunward, which calls for the aft-end axial thrusters 3A and=
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4A. The SK burn will follow an attitude reorientation scheduled for 16:20=
=20
UTC. The estimates given above should be considered accurate to first=20
order; improved accuracy will be possible following an orbit determination=
=20
update and Lissajous re-targeting based on that new orbit solution.
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OCRs Executed:
None
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Ongoing Activities:
Automation (ROBOTT):
- ROBOTTv0.9 delivered to String 1 on 09/27/03 (OCR GND_145).
-- Performing operations in "Auto" mode on String 1.
-- 13 DR fixes in this release.
--- 12 DRs have been verified by the FOT to date.
--- The last DR to be verified will require ROBOTT to be=20
observed over a period
of time to ensure no reoccurrence of the problem.
-- 13 DRs have been written against this release.
- ACE transitioned to Lights Out Operations on 11/13/04. All nominal=20
realtime operations are now being performed using ROBOTT, with the=20
exceptions of maneuvers and special commanding.
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Extra Spacecraft Activities:
Received a request from Jim Griffee (SWEPAM) to investigate the possibility=
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of commanding the SWEPAM-Ion instrument to collect certain data. The goal=
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is to characterize the instrument's spectral sensitivity to CEM voltage=20
steps, but doing so in the presence of an ever varying "calibration"=20
signal...the real-time solar wind. A telecon will occur at 1800Z,=20
12/07/04, to further discuss the data collection requirements and the=20
feasibility of commanding the instrument to capture that data.
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Anomalies:
DOY 04333 (11/28/04) ACE Anomaly S04-0018 =AD SWICS YL Limit Violation
Mnemonic SSCPAP5V violated the yellow low limit of 4.25 once during the=20
pass from 14:01:11 - 14:01:23, the value was 4.208. Notified Jim=20
Raines. Impact: Unknown.
DOY 04334 (11/29/04) ACE Anomaly S04-0019 - SWICS YL Limit Violation
Mnemonic SSCGR20V violated its YL limit twice. (1) 333-18:01:55-18:02:19,=20
value 17.00 and (2) 13:11:22-13:11:46, value 16.90. Notified Jim=20
Raines. IMPACT: Unknown
DOY 04335 (11/30/04) ACE Anomaly G04-0146 - ROBOTT - Command Capability=20
Acquired Late
FOT received page "Commanding Acquired 10 minutes after=20
Acquisition/BOT". C&C still beeping and reporting "Command Failure" after=
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command capability acquired. FOT verified Automation was running properly=
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and used "clear problem" button to end the beeping. IMPACT: Minimal. DR=20
CDSID# 0021074
DOY 04336 (12/01/04) ACE Anomaly G04-0147 - H/W - Workstation AC1WS2 Failed
All workstations were shutdown and powered off for transition to the new=20
UPS (Uninteruptable Power Supply). After the UPS transition was complete=
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and while starting all of the workstations, SysAdmin found that ac1ws2 was=
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unable to access boot partition. IMPACT: Primary operations switched to=20
String 2 with String 3 as backup for operations beginning 12/02/04.
DOY 04337 (12/02/04) ACE Anomaly G04-0148 - ROBOTT - ROBOTT Failed To=20
Configure For Support
ROBOTT did not start TPOCC on String 2 workstations or XTerms. ROBOTT only=
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brought up TPOCC on Front-End 2. Developers notified. IMPACT: FOT=20
required to intervene, configure, and monitor pass in the event additional=
=20
problems occurred.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~