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
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
Investigate physical properties and composition of local interstellar medium for comparison to solar system and galactic abundance.
Measure cosmic ray nuclei and electrons without the interference of the heliosphere.
Gather data on astrophysical processes such as acceleration by supernova shockwaves, interstellar radio and x-ray emissions, nucleosynthesis, and the dynamics of interstellar medium.
Perform direct measurements of the size and structure of the heliosphere.
Agenda
Introduction/Background Repeated External Acceleration Concept Current Study Future Work Acknowledgements/References
Repeated External Acceleration
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
Architecture is reusable and expandable. Stations can carry out other functions in-situ. Major issues include trajectory planning, station and probe hardware configurations
Agenda
Introduction/Background Repeated External Acceleration Concept Current Study Trajectory Analysis Station Configuration Probe Configuration
Future Work Acknowledgements/References
Trajectory Analysis
Critical Trajectory Features
Reach 200AU in 10-15 years Exit heliosphere in direction of bow shock
Problem Space Simplification
No station at Mars due to small gravity assist available Stations at multiple outer planets avoided due to long orbital periods Two main cases
Single station in Earth orbit Dual stations in Earth and Jupiter orbits
Basic Calculations Based on travel to 200AU in 15 years:
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
SNAP – NASA Glenn
MIDAS – Jet Propulsion Laboratory
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
Industry standard trajectory planning tool
SNAP
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
Input files for the two cases of station configuration are being created.
Case 1 – Single station in LEO Case 2 – Dual stations in LEO and Jupiter orbits
Station accelerations currently modeled as impulsive.
Further Optimization
By wrapping an optimization code around SNAP, more efficient trajectories can be found.
Currently, a simple optimizer is being written using GNU/Octave.
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
MagBeam Station Selected
Scaleable system. Does not require large space structure. Longer interaction times reduce spacecraft loading. Hardware currently being demonstrated.
Probe Configuration
Pluto New Horizons spacecraft shares many characteristics with interstellar probes.
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
Introduction/Background Repeated External Acceleration Concept Current Study Future Work/Outreach Acknowledgements/References
Continuing Work & Outreach
Complete trajectory analysis
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
Introduction/Background Repeated External Acceleration Concept Current Study Future Work/Outreach Acknowledgements/References
Acknowledgements
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?