Living Off the Land in Space LIVING OFF THE LAND IN SPACE Green Roads to the Cosmos Gregory L. Matloff Les Johnson C Bangs Copernicus Books An Imprint of Springer Science+Business Media In Association with Praxis Publishing Ltd © 2007 Springer Science+Business Media, LLC All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photo- copying, recording, or otherwise, without the prior written permission of the publisher. Published in the United States by Copernicus Books, an imprint of Springer Science+Business Media. Copernicus Books Springer Science+Business Media 233 Spring Street New York, NY 10013 www.springer.com Library of Congress Control Number: 2007922441 Manufactured in the United States of America. Printed on acid-free paper. 9 8 7 6 5 4 3 2 1 ISBN 978-0-387-36054-6 e-ISBN 978-0-387-68316-4 CONTENTS FOREWORD xi ACKNOWLEDGMENTS xiii INTRODUCTION: CITIZENS OF THE COSMOS 1 Further Reading 5 CHAPTER 1: THE OLD FRONTIER 9 Paleolithic Migrations 10 Neolithic and Bronze Age Migrants 11 Historical Migrations 12 Further Reading 15 CHAPTER 2: THE NEW FRONTIER 17 The Moon as a Habitat 18 Living Among the Near-Earth Objects 20 The Lure of Mars 22 Settling the Outer Solar System 24 Interstellar Environments 25 Further Reading 26 CHAPTER 3: THE ROCKET AND ITS LIMITS 29 Rocket Fundamentals 33 Rocket Varieties 36 Electric Rockets 36 Nuclear-Thermal and Solar-Thermal Rockets 37 Rocket Futures 38 Further Reading 38 v Contents CHAPTER 4: THE FIRST ``GREEN'' SPACE TECHNOLOGIES 41 Aeroassisted Atmospheric Reentry 42 Planetary Gravity Assists 44 Further Reading 47 CHAPTER 5: PROBES TO THE PLANETS: WHERE WE'VE BEEN ON OUR JOURNEY 51 Robots to the Moon! 52 The Lure of Our Sister Planet 54 Blistering Mercury 55 Tantalizing Mars 56 Distant Giants 60 Small Worlds 63 Further Reading 65 CHAPTER 6: PROBES TO THE STARS: CONCEPT STUDIES 67 Interstellar H-Bombs 69 A Sanitized Orion 70 Some Wonderful Improbabilities 72 TAU: NASA's First Interstellar Probe Study 73 Star Sailing 74 Further Reading 77 CHAPTER 7: BREAKING OUT INTO SPACE: VISIONARYFUTURES 79 Cylinder Cities 81 Power for the Earth 83 Beyond the Space Cylinders 85 Life in the Space Cities 86 Further Reading 88 CHAPTER 8: THINKING INTERSTELLAR 91 Earthly and Understandable Units of Measure 92 Distance in the Solar System and Beyond 93 NASA's Interstellar Initiative and the Interstellar Probe Mission 96 Further Reading 102 CHAPTER 9: TECHNOLOGICAL READINESS 105 Technology Readiness Levels 107 TRL-1: Basic Principles Observed and Reported 107 TRL-2: Basic Principles Observed and Reported 108 vi Contents TRL-3: Analytical and Experimental Critical Function and/or Characteristic Proof of Concept 109 TRL-4: Component and/or Breadboard Validation in a Laboratory Environment 110 TRL-5: Component and/or Breadboard Validation in a Relevant Environment 111 TRL-6: System or Subsystem Model or Prototype Demonstration in a Relevant Environment (Ground or Space) 112 TRL-7: System Prototype Demonstration in a Space Environment 115 TRL-8: Actual System Completed and ``Flight Qualified'' Through Test and Demonstration (Ground or Space) 116 Conclusion 116 Further Reading 116 CHAPTER 10: SPACE BRAKES (``LIVING OFF THE LAND'' BYUSING A PLANETARYATMOSPHERE) 119 Aeroentry 120 Aerobraking 121 Aerocapture 123 Aerocapture Application to Solar-System Resource Surveys 126 Some Aerocapture Issues 127 Aerogravity Assist 128 Further Reading 128 CHAPTER 11: THE ION TRAIL 131 Ion Drive History 132 Electric-Propulsion Fundamentals 133 Initial Interplanetary Application of Ion Propulsion 135 Possible Ion Propulsion Technology Application to Solar-System Development 137 Further Reading 138 CHAPTER 12: THE ORBITAL STEAM LOCOMOTIVE 141 Solar-Thermal Rocket Fundamentals 142 Near-Term Application of Solar-Thermal Rockets 144 vii Contents Possible Application of Solar-Thermal Technology to Solar-System Development 146 Further Reading 146 CHAPTER 13: SKYCLIPPERS 149 Photon Sailing History 150 Solar Sailing Fundamentals 151 Current Sail Technology 153 Missions for Near-Term Solar Photon Sails 156 Near-Future Solar-Sail Development Possibilities 158 Solar-Photon Sails and Space Development 159 Further Reading 159 CHAPTER 14: ART OR SCIENCE? 161 The Message Plaques 162 The Pioneer Plaques 162 The Voyager Plaques 164 A Future Message Plaque Possibility: Holography 165 Further Reading 167 CHAPTER 15: SPACE BEANSTALKS 169 Electrodynamic Tethers: Tapping a Planet's Magnetic Field for Power and Propulsion 170 Tethers for Propulsion and Power at Jupiter 176 Momentum Exchange Electrodynamic Reboost (MXER) Tethers 179 Further Reading 183 CHAPTER 16: CHEMICAL PROPULSION FOR SPACE EXPLORATION: GOOD FOR YESTERDAY, TODAY AND TOMORROW 185 The Moon: A Refueling Depot for Deep-Space Exploration 187 Mars: The Red Planet May Provide Fuel for Round Trip Travel to Earth 188 Jupiter, Saturn, Uranus, and Neptune: Our Next Stops 189 Asteroids and Comets: Abundant and Dispersed Gas Stations 190 CHAPTER 17: HUMAN EXPLORATION 193 Aerocapture 195 viii Contents Solar-Electric Propulsion 196 Solar-Thermal Propulsion 197 Solar Sails 199 Space Tethers 200 CHAPTER 18: DEFENDING THE EARTH 203 Nuclear Impact-Threat Mitigation 205 Using Space Resources to Mitigate the Threat 206 Further Reading 208 CHAPTER 19: SPACE MINERS 211 Possible Near-Earth Resource Locations 212 Preliminary Exploration 215 Mining the Atens 215 Tapping More Distant Space Mines 217 Further Reading 217 CHAPTER 20: SOME EXOTIC POSSIBILITIES 219 Plasma Sails 220 Magnetic Propulsion 222 Antimatter Propulsion 222 Breakthrough Propulsion Physics 225 Replacing the Rocket: Antigravity 226 Replacing the Rocket: Thrust Machines 226 Tapping ZPE and Getting Something for Nothing 227 Hyperspace Shortcuts 227 Instant Earths 228 The Red-Eye Special 229 Further Reading 229 CHAPTER 21: SIGHTS ON CENTAURUS 233 The First Starships 234 The Slow Boat to the Stars 235 Fast Ships 237 Spreading Through the Galaxy 238 Further Reading 239 AFTERWORD 241 INDEX 243 ix