DOCSLIB.ORG

The Plasma Magnet Sail by Connor O’Keefe Manned Interplanetary Travel Is a Project Which Has Retained the Interest of the World for Several Decades Now

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Plasma Magnet Sail by Connor O’Keefe Manned Interplanetary Travel Is a Project Which Has Retained the Interest of the World for Several Decades Now The Plasma Magnet Sail By Connor O’Keefe Manned interplanetary travel is a project which has retained the interest of the world for several decades now. However, organizations are hesitant to embark on such a journey because of cosmic radiation. The effects of this radiation are mysterious, and nobody is willing to risk lives on a multi-month mission to another planet such as Mars with such little knowledge of the obstacle. The use of a plasma magnet sail is an effective way to bypass this obstacle, due to its energy efficiency and high-speed capability. The basic idea of the plasma magnet sail is to use a vast magnetic field to receive momentum from solar wind and other charged particles to accelerate. This approach is highly cost-effective since great speeds can be reached with the input of relatively small amounts of power. This paper is meant to summarize in part John Slough’s paper discussing the plasma magnet and its capabilities. It is highly condensed in favor of simplicity and conciseness, and it is directed to students and professionals interested in the concept of fast interplanetary travel. Technological Overview A magnetic solar sail is a conceptual design for spacecraft propulsion much like a sailboat. The wind is analogous to the charged particles from the sun and the sail is analogous to the magnetic field induced by a current. The plasma magnet sail is based on the concept of the magnetic sail, however there are a few key differences. The plasma magnet sail requires no added current, theoretically requires no propellant, and most importantly it requires less mass to build. This overview will give a sense of how it works and why it is so important. The Plasma Magnetic Rotor The plasma magnet rotor uses two pairs of polyphase coils (shown in blue and red) which utilize an alternating current (AC) to create a rotating magnetic field (RMF). The AC excites plasma electrons in the RMF which interact with ions that move through the field. This interaction between electrons and ions is what allows the conversion of electrical power to mechanical work. This can be used to create thrust as charged particles (e.g. solar winds) pass through the field. Figure 1 – Laboratory build (left) and computer Figure 2 – The polyphase coils create a rotating model (right) of what this looks like magnetic field The Traditional Magnetic Sail Figure 3 - Traditional MagSail A spacecraft can utilize a magnetic field to create thrust with ridiculously small amounts of energy, allowing the creation of craft with very high thrust-to-weight ratios. A traditional magnet sail is formed by antennae which extend out in front of the craft, using a current to create a magnetic field that interacts with charged particles coming from behind. It not only enables the craft to accelerate forward quickly, but also backward, allowing the craft to slow down. The method for doing this is explained in the stopping section. Why the Plasma Magnet Sail is Different With a plasma magnet, there is no need for an applied current since the current is induced by the RMF itself. This is important because it allows the creation of a virtually massless sail which is made of solar wind “trapped” by the magnetic field (Figure 4) instead of bulky metal wire sails that carry a current. For one, it minimizes the use of fuel, which makes it a desirable option for an engine. In addition, the magnetic field can be much larger than the motor which it is created by. These are the key innovations presented by this method. The experiments in Slough’s paper show that the size of the magnetic field is inversely proportional to the pressure from solar particles. Therefore, the force from the passing particles is constant even as a hypothetical spacecraft moves away from the sun. This is what gives a spacecraft utilizing this technology the ability to accelerate to such high speed. Figure 4 - Plasma Magnet Sail In addition, the plasma magnet in theory requires no propellant, unlike a classical magnetic sail which requires an applied electrical current to work. Because the Earth’s magnetosphere deflects solar winds, a spacecraft using this technology would need to be orbiting past the moon’s orbit to use the solar wind as propulsion. The spacecraft would then be able to travel outward, following the output of solar wind. An optimal orbit transfer would enable a spacecraft to travel to Mars in a week (Greason) and would allow speeds of up to 0.2% of the speed of light during interstellar transfer. Mission Logistics The plasma magnet sail has quite a few applications, such as fast travel within the Earth’s magnetosphere, to asteroids, to the Oort cloud, or even to Alpha Centauri. For the purposes of this explanation, it will be used for a mission to Mars. Because the main concern when discussing a Mars mission is cosmic radiation, the fact that the sail enables a week-long trip to Mars is an effective motive for the application of this sail. Cosmic Radiation The plasma magnet sail overcomes the effects of cosmic radiation with its ability to speed through hostile interplanetary space. Since the sail would be able to accelerate using the Earth’s magnetosphere, it can reach high speeds before it even leaves the protection of the magnetosphere. Stopping Another issue that comes to mind is stopping such a fast spacecraft. It is obvious that the sail would be viable on its own for stopping during interstellar travel due to its ability to receive opposing thrust from the destination star. But the method for stopping without the help of another star is not as simple. Jeff Greason proposed a solution to this issue: To use particle beams aimed at the magnetic field to slow the spacecraft down. This would require the installation of a particle beam using matter from the destination to shoot at the incoming spacecraft’s magnetic field. In the case of a Mars mission, particle accelerators could be installed on either Phobos or Deimos, extracting matter from them and shooting it at the spacecraft’s magnetic field to slow it down. This would not be very difficult to aim, since at this point the magnetic field would be hundreds of thousands of miles in diameter. The beam would need to shoot matter equal to the mass of the spacecraft in order to slow it to a reasonable speed, so depending on the mass of the spacecraft and the size of the body being exploited for matter, this may or may not be viable. Works Cited Slough, John “The plasma magnet” (2006). NASA Institute for Advanced Concepts Phase 1 Final Report. Greason, Jeff “Missions Enabled by plasma magnet Sails”, Presentation at the Tennessee Valley Interstellar Workshop, 2017. https://www.youtube.com/watch?v=0vVOtrAnIxM Gilster, Paul “The Plasma Magnet Drive: A Simple, Cheap Drive for the Solar System and Beyond”, Centauri Dreams - Imagining and Planning Interstellar Exploration, https://www.centauri-dreams.org/2017/12/29/the-plasma-magnet-drive-a-simple- cheap-drive-for-the-solar-system-and-beyond/ Figure 1, 2, 3 – Slough, John Figure 4 – Gilster, Paul .
Load more

Recommended publications
  • Breakthrough Propulsion Study Assessing Interstellar Flight Challenges and Prospects
    Breakthrough Propulsion Study Assessing Interstellar Flight Challenges and Prospects NASA Grant No. NNX17AE81G First Year Report Prepared by: Marc G. Millis, Jeff Greason, Rhonda Stevenson Tau Zero Foundation Business Office: 1053 East Third Avenue Broomfield, CO 80020 Prepared for: NASA Headquarters, Space Technology Mission Directorate (STMD) and NASA Innovative Advanced Concepts (NIAC) Washington, DC 20546 June 2018 Millis 2018 Grant NNX17AE81G_for_CR.docx pg 1 of 69 ABSTRACT Progress toward developing an evaluation process for interstellar propulsion and power options is described. The goal is to contrast the challenges, mission choices, and emerging prospects for propulsion and power, to identify which prospects might be more advantageous and under what circumstances, and to identify which technology details might have greater impacts. Unlike prior studies, the infrastructure expenses and prospects for breakthrough advances are included. This first year's focus is on determining the key questions to enable the analysis. Accordingly, a work breakdown structure to organize the information and associated list of variables is offered. A flow diagram of the basic analysis is presented, as well as more detailed methods to convert the performance measures of disparate propulsion methods into common measures of energy, mass, time, and power. Other methods for equitable comparisons include evaluating the prospects under the same assumptions of payload, mission trajectory, and available energy. Missions are divided into three eras of readiness (precursors, era of infrastructure, and era of breakthroughs) as a first step before proceeding to include comparisons of technology advancement rates. Final evaluation "figures of merit" are offered. Preliminary lists of mission architectures and propulsion prospects are provided.
    [Show full text]
  • Magnetoshell Aerocapture: Advances Toward Concept Feasibility
    Magnetoshell Aerocapture: Advances Toward Concept Feasibility Charles L. Kelly A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Aeronautics & Astronautics University of Washington 2018 Committee: Uri Shumlak, Chair Justin Little Program Authorized to Offer Degree: Aeronautics & Astronautics c Copyright 2018 Charles L. Kelly University of Washington Abstract Magnetoshell Aerocapture: Advances Toward Concept Feasibility Charles L. Kelly Chair of the Supervisory Committee: Professor Uri Shumlak Aeronautics & Astronautics Magnetoshell Aerocapture (MAC) is a novel technology that proposes to use drag on a dipole plasma in planetary atmospheres as an orbit insertion technique. It aims to augment the benefits of traditional aerocapture by trapping particles over a much larger area than physical structures can reach. This enables aerocapture at higher altitudes, greatly reducing the heat load and dynamic pressure on spacecraft surfaces. The technology is in its early stages of development, and has yet to demonstrate feasibility in an orbit-representative envi- ronment. The lack of a proof-of-concept stems mainly from the unavailability of large-scale, high-velocity test facilities that can accurately simulate the aerocapture environment. In this thesis, several avenues are identified that can bring MAC closer to a successful demonstration of concept feasibility. A custom orbit code that dynamically couples magnetoshell physics with trajectory prop- agation is developed and benchmarked. The code is used to simulate MAC maneuvers for a 60 ton payload at Mars and a 1 ton payload at Neptune, both proposed NASA mis- sions that are not possible with modern flight-ready technology. In both simulations, MAC successfully completes the maneuver and is shown to produce low dynamic pressures and continuously-variable drag characteristics.
    [Show full text]
  • 9Th Annual & Final Report 2006 2007
    NASA Institute for Advanced Concepts 9th Annual & 2006 Final Report 2007 Performance Period July 12, 2006 - August 31, 2007 NASA Institute for Advanced Concepts 75 5th Street NW, Suite 318 Atlanta, GA 30308 404-347-9633 www.niac.usra.edu USRA is a non-profit corpora- ANSER is a not-for-profit pub- tion under the auspices of the lic service research corpora- National Academy of Sciences, tion, serving the national inter- with an institutional membership est since 1958.To learn more of 100. For more information about ANSER, see its website about USRA, see its website at at www.ANSER.org. www.usra.edu. NASA Institute for Advanced Concepts 9 t h A N N U A L & F I N A L R E P O R T Performance Period July 12, 2006 - August 31, 2007 T A B L E O F C O N T E N T S 7 7 MESSAGE FROM THE DIRECTOR 8 NIAC STAFF 9 NIAC EXECUTIVE SUMMARY 10 THE LEGACY OF NIAC 14 ACCOMPLISHMENTS 14 Summary 14 Call for Proposals CP 05-02 (Phase II) 15 Call for Proposals CP 06-01 (Phase I) 17 Call for Proposals CP 06-02 (Phase II) 18 Call for Proposals CP 07-01 (Phase I) 18 Call for Proposals CP 07-02 (Phase II) 18 Financial Performance 18 NIAC Student Fellows Prize Call for Proposals 2006-2007 19 NIAC Student Fellows Prize Call for Proposals 2007-2008 20 Release and Publicity of Calls for Proposals 20 Peer Reviewer Recruitment 21 NIAC Eighth Annual Meeting 22 NIAC Fellows Meeting 24 NIAC Science Council Meetings 24 Coordination With NASA 27 Publicity, Inspiration and Outreach 29 Survey of Technologies to Enable NIAC Concepts 32 DESCRIPTION OF THE NIAC 32 NIAC Mission 33 Organization 34 Facilities 35 Virtual Institute 36 The NIAC Process 37 Grand Visions 37 Solicitation 38 NIAC Calls for Proposals 39 Peer Review 40 NASA Concurrence 40 Awards 40 Management of Awards 41 Infusion of Advanced Concepts 4 T A B L E O F C O N T E N T S 7 LIST OF TABLES 14 Table 1.
    [Show full text]
  • Research Status of Sail Propulsion Using the Solar Wind
    J. Plasma Fusion Res. SERIES, Vol. 8 (2009) Research Status of Sail Propulsion Using the Solar Wind Ikkoh FUNAKI1,3, and Hiroshi YAMAKAWA2,3 1) Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 229-8510, Japan 2) Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto 611-0011, Japan 3) Japan Science and Technology Agency (JST), CREST, Kawaguchi, Saitama 332-0012, Japan (Received: 1 September 2008 / Accepted: 22 October 2008) A spacecraft propulsion system utilizing the energy of the solar wind was reviewed. The first plasma sail concept was proposed by Prof. Winglee in 2000, and that was called M2P2 (mini-magnetospheric plasma-propulsion). However, the first M2P2 design adopting a small (20-cm-diamter) coil and a small helicon plasma source design was criticized by Dr. Khazanov in 2003. He insisted that: 1) MHD is not an appropriate approximation to describe the M2P2 design by Winglee, and with ion kinetic simulation, it was shown that the M2P2 design could provide only negligible thrust; 2) considerably larger sails (than that Winglee proposed) would be required to tap the energy of the solar wind. We started our plasma sail study in 2003, and it was shown that moderately sized magnetic sails in the ion inertial scale (~70 km) can produce sub-Newton-class thrust. Currently, we are continuing our efforts to make a feasibly sized plasma sail (Magnetoplasma sail) by optimizing its physical processes and spacecraft design. Keywords: spacecraft propulsion, sail propulsion, plasma Sail, Magnetic Sail, M2P2, MPS 1. Introduction Although the MagSail requires a large hoop coil, Winglee proposed an idea to use a very compact coil to In 2005, after a cruising of more than 25 years, it was obtain a large MagSail; he proposed to inflate the original reported that the Voyager 1 spacecraft has entered the solar system's final frontier, a vast, turbulent expanse where the weak magnetic field by injecting a plasma jet from a spacecraft (Fig.1b)[6 ].
    [Show full text]
  • IGNITION! an Informal History of Liquid Rocket Propellants by John D
    IGNITION! U.S. Navy photo This is what a test firing should look like. Note the mach diamonds in the ex­ haust stream. U.S. Navy photo And this is what it may look like if something goes wrong. The same test cell, or its remains, is shown. IGNITION! An Informal History of Liquid Rocket Propellants by John D. Clark Those who cannot remember the past are condemned to repeat it. George Santayana RUTGERS UNIVERSITY PRESS IS New Brunswick, New Jersey Copyright © 1972 by Rutgers University, the State University of New Jersey Library of Congress Catalog Card Number: 72-185390 ISBN: 0-8135-0725-1 Manufactured in the United Suites of America by Quinn & Boden Company, Inc., Rithway, New Jersey This book is dedicated to my wife Inga, who heckled me into writing it with such wifely re­ marks as, "You talk a hell of a fine history. Now set yourself down in front of the typewriter — and write the damned thing!" In Re John D. Clark by Isaac Asimov I first met John in 1942 when I came to Philadelphia to live. Oh, I had known of him before. Back in 1937, he had published a pair of science fiction shorts, "Minus Planet" and "Space Blister," which had hit me right between the eyes. The first one, in particular, was the earliest science fiction story I know of which dealt with "anti-matter" in realistic fashion. Apparently, John was satisfied with that pair and didn't write any more s.f., kindly leaving room for lesser lights like myself.
    [Show full text]
  • Plasma Sail Propulsion Based on the Plasma Magnet
    Plasma Sail Propulsion Based on the Plasma Magnet IEPC-2007-15 Presented at the 30th International Electric Propulsion Conference, Florence, Italy September 17-20, 2007 John Slough* University of Washington, Seattle, WA, 98195, USA Abstract: Propulsion based on the plasma magnet taps the ambient energy of the solar wind via the coupling to a large-scale (30 km) dipolar magnetic field generated by two polyphase antennae that drive currents in the plasma to create, inflate and maintain the magnetic structure. In scaled a laboratory experiment, all aspects of the plasma magnet as a propulsion system were explored and validated. A solar wind source (SWS) of the appropriate flow velocity and power was deflected by a plasma magnet whose antennae were attached to a ballistic pendulum. A large displacement attributable only to the deflection of the SWS by the plasma current generated dipole magnetic fields was observed. The inferred thrust from deflection of the SWS was 2N during the time of operation providing an equivalent “jet” power of 1 MW. Nomenclature BRMF = magnitude of rotating magnetic field B = magnitude of steady axial magnetic field BMP = magnitude of magnetospheric field at the magnetopause 2 β = ratio of plasma to magnetic field energy density i.e. nkT/(B /2μ0) Isp = Specific Impulse δ = classical skin depth in a conductor D⊥ = particle diffusion coefficient Eθ = azimuthal component of the induced electric field EB = energy stored in magnetic field Iθ = total driven azimuthal current jθ = azimuthal current density ne = plasma electron
    [Show full text]
  • Phase I Final Report (PDF)
    A Plasma Aerocapture and Entry System for Manned Missions and Planetary Deep Space Orbiters MSNW LLC A Plasma Aerocapture and Entry System for Manned Missions and Planetary Deep Space Orbiters Phase I Final Report PREPARED BY: David Kirtley MSNW LLC. 8551 154th Ave NE Redmond, WA 98052 Phone: (425) 867 8900 Email: [email protected] Contract Number: NNX12AR12G Report Number: Final Report DISTRIBUTION STATEMENT A – Public Release; Distribution is Unlimited. 1 A Plasma Aerocapture and Entry System for Manned Missions and Planetary Deep Space Orbiters MSNW LLC Table of Contents Table of Contents ............................................................................................................................ 2 General Project Abstract ................................................................................................................. 3 Technical Project Summary ............................................................................................................ 4 Phase I Work Plan ........................................................................................................................... 5 Nomenclature .................................................................................................................................. 7 Background: Magnetoshell Physical Description ........................................................................... 9 Basic parameter scaling of a Magnetoshell for Aerobraking ...................................................... 9 Low Beta Equilibrium ..............................................................................................................
    [Show full text]
  • Summary of Opportunities in the Fusion Energy Sciencesprogram
    Summary of Opportunities in the Fusion Energy Sciences Program Prepared by the Fusion Energy Sciences Advisory Committee For the Office of Science of the U.S. Department of Energy SUMMARY OF OPPORTUNITIES IN THE FUSION ENERGY SCIENCES PROGRAM November 1999 Prepared by the Fusion Energy Sciences Advisory Committee for the Office of Science of the U.S. Department of Energy Fusion Energy Sciences Advisory Committee Panel * Charles C. Baker, University of California, San Diego Stephen O. Dean, Fusion Power Associates † N. Fisch, Princeton Plasma Physics Laboratory Jeffrey P. Freidberg,* Massachusetts Institute of Technology Richard D. Hazeltine,* University of Texas G. Kulcinski, University of Wisconsin John D. Lindl,* Lawrence Livermore National Laboratory Gerald A. Navratil,* Columbia University Cynthia K. Phillips,* Princeton Plasma Physics Laboratory S. C. Prager, University of Wisconsin D. Rej, Los Alamos National Laboratory John Sheffield,* Oak Ridge National Laboratory, Coordinator J. Soures, University of Rochester R. Stambaugh, General Atomics R. D. Benson, ORNL Support J. Perkins, LLNL Support J. A. Schmidt, PPPL Support N. A. Uckan, ORNL Support * Member of FESAC. † Ex-Member of FESAC. ii Fusion Energy Sciences Advisory Committee 1998–1999 Members Dr. Charles C. Baker, University of California, San Diego Dr. Richard J. Briggs, Science Applications International Corporation Dr. Robert W. Conn, University of California, San Diego Professor Jeffrey P. Freidberg, Massachusetts Institute of Technology Dr. Katharine B. Gebbie, National Institute of Standards and Technology Professor Richard D. Hazeltine, University of Texas at Austin Professor Joseph A. Johnson III, Florida A&M University Dr. John D. Lindl, Lawrence Livermore National Laboratory Dr. Gerald A. Navratil, Columbia University Dr.
    [Show full text]
  • Extraction of Antiparticles Concentrated in Planetary Magnetic Fields
    DRAPER LABORATORY EXTRACTION OF ANTIPARTICLES CONCENTRATED IN PLANETARY MAGNETIC FIELDS JAMES BICKFORD PRINCIPAL INVESTIGATOR NIAC PHASE II YEAR 1 REPORT AUGUST 2007 555 TECHNOLOGY SQUARE CAMBRIDGE, MA 02139 TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................................. 2 ACKNOWLEDGEMENTS ......................................................................................................................... 4 CHAPTER 1 – BACKGROUND AND SUMMARY ................................................................................. 5 OVERVIEW .................................................................................................................................................. 5 UTILITY OF ANTIMATTER ........................................................................................................................... 6 CURRENT PRODUCTION AND STORAGE CAPABILITIES ................................................................................ 8 IN SITU PRODUCTION AND TRANSPORT ...................................................................................................... 9 NATURAL SOURCES OF ANTIPROTONS ...................................................................................................... 11 ANTIPROTON COLLECTORS ....................................................................................................................... 13 SYSTEM CONCEPT ....................................................................................................................................
    [Show full text]
  • Preparation of Papers for AIAA Technical Conferences
    The Plasma Magnet NASA Institute for Advanced Concepts Phase II Final Report John Slough Department of Aeronautics and Astronautics University of Washington Seattle, WA 98105 1 Final Report On The Plasma Magnet Summary Plasma sail propulsion based on the plasma magnet is a unique system that taps the ambient energy of the solar wind with minimal energy and mass requirements. The coupling to the solar wind is made through the generation of a large-scale (~> 30 km) dipolar magnetic field. Unlike the original magnetic sail concept, the coil currents are conducted in a plasma rather than a superconducting coil. In this way the mass of the sail is reduced by orders of magnitude for the same thrust power. The plasma magnet consists of a pair of polyphase coils that produce a rotating magnetic field (RMF) that drives the necessary currents in the plasma to inflate and maintain the large-scale magnetic structure. The plasma magnet is deployed by the Lorentz self-force on the plasma currents, expanding outward in a disk-like shape until the expansion is halted by the solar wind pressure. It is virtually propellantless as the intercepted solar wind replenishes the small amount of plasma required to carry the magnet currents. Unlike a solid magnet or sail, the plasma magnet expands with falling solar wind pressure to provide a constant force. In phase I a small prototype plasma magnet was built and tested. The Phase I experiments demonstrated the ability to drive sufficient current in the plasma magnet to have the resultant dipole field push out well beyond the 10 km scale required for significant interaction with the solar wind.
    [Show full text]
  • DPP Newsletter.Indd
    The DPP Chronicle Savannah, Georga A Division of The American Physical Society November, 2004 Hurry -- My presentation is in just five minutes! Women in Plasma Physics applications; a computational environment DPP Banquet Invited Paper Poster that ensures effective utilization of that architecture for scientific discovery; a best- Sessions Luncheon After-Dinner Speaker: James Maas in-class communications network and data Cornell University, “Everything you should Monday, November 15, 12 noon to management infrastructure; and teams of Poster versions of review, invited, and know about sleep but are too tired to ask”. 1:30 p.m. Harbor Ballroom A, Westin leading experts applying this capability to tutorial papers are optional and are sched- Wednesday, November 17, 2004 at The Hotel critical research challenges. uled Monday through Friday, in the fol- Westin Hotel: Professors Halima Ali, Hampton The National Leadership Computing lowing half-day session, in a designated University, and Linda Vahala, Old Facility (NLCF) engages a world-class Cocktails - Harbor Ballroom - 6:30 p.m. area of Exhibit Hall A. For example, Dominion University, will speak briefly team from national laboratories, research Banquet - Grand Ballroom - 7:30 p.m. the Monday morning review and invited about “Academic Career Paths in Plasma institutions, computing centers, univer- talks may also be presented as posters Physics” during the luncheon. Cost for sities, and vendors to take a dramatic DPP in the Monday afternoon poster session. lunch will be $25, except for graduate and step forward to field a new capability This option will be available on Monday undergraduate women who will pay $5, for high-end science.
    [Show full text]
  • The Plasma Magnet
    NASA Institute for Advanced Concepts Phase I Fellows Meeting The Plasma Magnet John Slough University of Washington March 23-24, 2004 Development of the Plasma Magnet for Deep Space Exploration John Slough, Samuel Andreason, and Louis Giersch Research Institute for Space Exploration University of Washington The Plasma Magnet •The singularly most important aspect is the possibility of achieving multi-Megawatt thrust power from the solar wind. •The ultimate spacecraft speed powered by the plasma magnet is that of the solar wind (350 to 800 km/s). •As opposed to the solar sails, the dynamic nature of the plasma magnet provides a constant thrust regardless of distance from the sun. •The jet power scales with the size of the magnetic bubble. A 20 kW rotating magnetic field (RMF) can produce a magnetic bubble intercepting up to 10 MW of thrust power. The effective “thruster” efficiency can be greater than 1 – and as large as η ~ 500 The Magnetic Sail (Zubrin and Andrews,1991) •The major difficulty in the original concept of course was the magnet mass. •The mass problem is solved by having the coil currents conducted in a plasma rather than a superconducting coil. In this way the mass of the sail is reduced by orders of magnitude for the same thrust power. •The question now becomes how to generate and sustain the currents How are the plasma currents generated and sustained? Plasma Magnet from Rotating Magnetic Fields RMF driven currents •No copper/superconducting magnet required •Results from Phase I Have demonstrated generation and sustainment
    [Show full text]