Interstellar Exploration
Through Repeated External
Acceleration
Andrew Bingham
NIAC Student Fellows Prize
Department of Mechanical and Aeronautical Engineering, Clarkson University
NIAC Fellows Meeting, March 7th-8th, 2006
Agenda
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Introduction/Background
Repeated External Acceleration Concept
Current Study
Future Work
Acknowledgements/References
The Heliosphere
Current Missions
•Voyager 1 & 2
•Pluto New Horizons
•Launched in 1977
•Launched December 2005
•Extended Interstellar mission
•Passing Termination Shock
•Extended mission to visit
Kuiper Belt Objects
•Communications until 2020 and
approximately 120 AU
•Communications until 2020
and approximately 50 AU
Future Scientific Objectives
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Investigate physical properties and
composition of local interstellar medium
for comparison to solar system and
galactic abundance.
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Measure cosmic ray nuclei and electrons
without the interference of the
heliosphere.
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Gather data on astrophysical processes
such as acceleration by supernova
shockwaves, interstellar radio and x-ray
emissions, nucleosynthesis, and the
dynamics of interstellar medium.
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Perform direct measurements of the
size and structure of the heliosphere.
Agenda
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Introduction/Background
Repeated External Acceleration Concept
Current Study
Future Work
Acknowledgements/References
Repeated External Acceleration
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Acceleration stations
external to the
spacecraft provide
primary propulsion.
Stations are positioned
throughout the solar
system.
Form a ‘solar system
sized slingshot’
Repeated External Acceleration
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Architecture is reusable and expandable.
Stations can carry out other functions in-situ.
Major issues include trajectory planning, station
and probe hardware configurations
Agenda
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Introduction/Background
Repeated External Acceleration Concept
Current Study
Trajectory Analysis
„ Station Configuration
„ Probe Configuration
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Future Work
Acknowledgements/References
Trajectory Analysis
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Critical Trajectory Features
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Reach 200AU in 10-15 years
Exit heliosphere in direction of
bow shock
Problem Space Simplification
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No station at Mars due to small
gravity assist available
Stations at multiple outer
planets avoided due to long
orbital periods
Two main cases
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Single station in Earth orbit
Dual stations in Earth and
Jupiter orbits
Basic Calculations
Based on travel to 200AU in 15 years:
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Single station at Earth requires Vinf = 63.2 km/s
Delta Vinf at Jupiter vs Delta Vinf at Earth, 200AU in 15 years
400
350
Delta Vinf Jupiter
300
250
200
150
100
50
0
10
„
20
30
40
Delta Vinf Earth
50
60
Dual 40 km/s stations at Earth & Jupiter
70
Requested Software
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SNAP – NASA Glenn
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MIDAS – Jet Propulsion Laboratory
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Spacecraft N-Body Analysis Program
Propagates using 8th order Runge-Kutta Fehlberg routine
Patched conic trajectory optimization program
Capable of automatically varying, adding, deleting mission
phases
Satellite Toolkit
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Industry standard trajectory planning tool
SNAP
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SNAP runs in Linux and
other UNIX/BSD
environments.
Input and output are in
the form of formatted
text.
Fortran source code is
available for custom
applications.
Does not perform
optimization.
SNAP
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Input files for the two
cases of station
configuration are being
created.
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Case 1 – Single station in
LEO
Case 2 – Dual stations in
LEO and Jupiter orbits
Station accelerations
currently modeled as
impulsive.
Further Optimization
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By wrapping an optimization code around
SNAP, more efficient trajectories can be found.
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Currently, a simple optimizer is being written
using GNU/Octave.
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Capable of varying parameters within the
representative input files and comparing resulting
output for mission success based on critical
trajectory limitations.
Station Configuration
Linear Accelerator
MagBeam
Tether
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MagBeam Station Selected
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Scaleable system.
Does not require large space structure.
Longer interaction times reduce spacecraft loading.
Hardware currently being demonstrated.
Probe Configuration
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Pluto New Horizons spacecraft
shares many characteristics with
interstellar probes.
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Long-duration deep space mission.
Mass minimized (~500kg) to
achieve high velocity.
Some instruments designed to
measure plasma and solar wind
interactions.
Further reducing the payload
mass through miniaturization
could allow the use of a PNHderived spacecraft for an
externally accelerated mission to
bow shock.
Instruments:
Probe Payload
•Magnetometer
•Plasma and Radio Wave Sensor
•Solar Wind/Interstellar Plasma/Electron Spectrometer
•Pickup and Interstellar Ion Isotope Spectrometer
•Interstellar Neutral Atom Spectrometer
•Suprathermal Ion/Electron Sensor
•Cosmic Ray H, He, Electron, Positron, Gamma-Ray Burst Instrument
•Anomalous & Galactic Cosmic Ray Isotope Spectrometer
•Dust Composition Instrument
•Infrared Instrument
•Energetic Neutral Atom (ENA) Imager
•UV Photometer
Resource Requirements:
•Power – 20W
•Communications – 25bps
•Mass – 25kg
Technology Readiness
Architecture Component
TRL
MagBeam System
TRL 4
Space Nuclear Power Supply
TRL 6
Autonomous Rendezvous
TRL 9
Advanced Deep Space Vehicle
TRL 9
Miniaturized Instrument Suite
TRL 3
Agenda
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Introduction/Background
Repeated External Acceleration Concept
Current Study
Future Work/Outreach
Acknowledgements/References
Continuing Work & Outreach
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Complete trajectory analysis
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Potential Case 3 – LEO + Mars Stations
Publish Web Site
Present at AIAA Region I-NE Student
Conference, March 30th-April 1st
Present at Clarkson University Symposium for
Undergraduate Research, April 7th
Final Report
Agenda
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Introduction/Background
Repeated External Acceleration Concept
Current Study
Future Work/Outreach
Acknowledgements/References
Acknowledgements
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NIAC, for providing the resources to continue
working on this project.
Dr. Kenneth Visser, for advising me throughout
the process.
NASA Glenn for providing SNAP.
AGI for providing STK.
Family, friends, and everyone else who
supported me throughout the last year.
References
Analytical Graphics, Inc, Satellite Toolkit, v.6.2.
Hoyt, et. al, A Modular Momentum-Exchange/Electrodynamic-Reboost Tether System
Architecture, AIAA-2003-2514.
Interstellar Boundary Explorer Science Strategy.
http://www.ibex.swri.edu/mission/strategy.shtml
Martini, Michael. Spacecraft N-Body Analysis Program 2.3 Users Guide. Analex
Corperation, NASA Glenn Research Center, 2005.
Mewaldt, R. A., and Liewar, P. C., An Interstellar Probe Mission to the Boundaries of the
Heliosphere and Nearby Interstellar Space, NASA Jet Propulsion Laboratory,
1999.
Pluto New Horizons Science Payload,
http://pluto.jhuapl.edu/spacecraft/sciencePay.html
Riehl, Phil. Tools Used By Analysis & Integration Group – MIDAS.
http://trajectory.grc.nasa.gov/tools/midas.shtml
Vallado, David A, Fundamentals of Astrodynamics and Applications,
Microcosm, 2001.
Winglee, et. al, Magnetized Beam Propulsion, NIAC Fellows Meeting 2005.
Questions?