The Future of Human Space Exploration
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THE FUTURE OF HUMAN SPACE EXPLORATION Giovanni Bignami and Andrea Sommariva With a foreword from the Director General of the European Space Agency The Future of Human Space Exploration Giovanni Bignami • Andrea Sommariva The Future of Human Space Exploration Giovanni Bignami Andrea Sommariva IASF-INAF Milan , Italy Milan , Italy ISBN 978-1-137-52657-1 ISBN 978-1-137-52658-8 (eBook) DOI 10.1057/978-1-137-52658-8 Library of Congress Control Number: 2016936718 © Th e Editor(s) (if applicable) and Th e Author(s) 2016 Th e author(s) has/have asserted their right(s) to be identifi ed as the author(s) of this work in accordance with the Copyright, Designs and Patents Act 1988. Th is work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and trans- mission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Th e use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Th e publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Cover illustration: © B.A.E. Inc. / Alamy Stock Photo Printed on acid-free paper Th is Palgrave Macmillan imprint is published by Springer Nature Th e registered company is Macmillan Publishers Ltd. London Foreword: The Future of Human Space Exploration by Johann Dietrich Woerner, General Director of the European Space Agency I n Th e Future of Human Space Exploration , Giovanni Bignami and Andrea Sommariva present a discussion of a very challenging topic: that of explo- ration. For the space community, exploration lies at the very core of space activity and brings together technology and science at the highest level. Exploration, whether robotic or human, requires that we think about possible eff ects that extend far beyond our day-to-day experience. Th e book focuses on all aspects of exploration, ranging from history, launcher and propulsion systems and spacecraft, to possible activities beyond sci- ence such as mining in the universe. It also covers the crucial aspects of human spacefl ight. Large parts of the book are written in such a way as to give even the less-informed reader a clear understanding of the subject. At the same time, those already with an in-depth understanding can fi nd detailed information about the physics that provides the background to these activities. Th e most challenging part of exploration is neither the technology nor the science. Rather, it is to convince those organisations that handle public money to invest in exploration. Th e problem is that exploration is looking into the unknown and therefore cannot seriously promise a direct return on investment on Earth. However, examples from the past show that all exploration missions have had additional eff ects beyond their initial scientifi c purpose. For example, it was investigations of Venus that disclosed the greenhouse eff ect on Earth (better known as “climate v vi Foreword: The Future of Human Space Exploration by Johann ... change”). For the Rosetta mission, a special camera was developed that was able to diff erentiate between diff erent shades of grey on the comet. Th is technology is now used for early forest-fi re detection by observing forests and indicating smoke vapour or fog. In addition, exploration mis- sions are usually organised in an international framework able to bridge earthly confl icts. A fi rst-rate example of this is the International Space Station in which astronauts and cosmonauts from the USA, Russia, Canada, Japan and Europe all work together very successfully. However, as such results are not the main objectives of exploration, there is a constant need to continue making the case for it. Contents 1 Introduction 1 2 Stepping Out of the Cradle: Th e Exploration of the Solar System from the 1950s to Today 5 3 Human Space Exploration in the “Deep Space Proving Grounds” 39 4 Th e Great Leap Out of the Cradle: Th e Human Exploration of Our Solar System 81 5 Th e Ultimate Challenge: Th e Exploration and Colonisation of Extrasolar Planets 131 6 Th e Uncertainties 161 Index 185 vii List of Figures Fig. 2.1 Space budgets of the main spacefaring nations 17 Fig. 2.2 Space agencies’ budgets as a percentage of GDP 17 Fig. 2.3 Turnover of the satellite industry 29 Fig. 3.1 Map of the asteroids 45 Fig. 3.2 Design of the spaceship 48 Fig. 3.3 Price dynamics 61 Fig. 3.4 Mission to an Aten asteroid 75 Fig. 3.5 Mission to an Apollo type of asteroid 77 Fig. 4.1 Topography of Mars 90 Fig. 4.2 Fission-fragment plasma-bed reactor 127 Fig. 4.3 Scheme of Th e Rubbia engine 128 Fig. 5.1 Original Leavitt graph 133 Fig. 5.2 Closest star systems to Earth 144 Fig. 5.3 Migrations of the Polynesian people 151 Fig. 6.1 China’s labour market and GDP growth 167 ix List of Tables Table 2.1 Specifi c impulses in seconds 23 Table 2.2 Costs of the heavy launchers 31 Table 2.3 Private space initiatives 33 Table 2.4 List of space investing billionaires 34 Table 3.1 Abundance of chemicals and metals on the Moon 41 Table 3.2 Change in velocity required for transfer of minerals to Earth orbit 43 Table 3.3 Abundance of PGMs and precious metals in asteroids 46 Table 3.4 Asteroid mass scaling, volumes, and values 53 Table 3.5 Characteristics of Asteroid 2004 MN4 57 Table 3.6 Changes in velocity 59 Table 3.7 Scenario 59 Table 3.8 Simulation results 62 Table 3.9 Rate of return on the investments and investment costs 62 Table 3.10 Metric for criticality 66 Table 4.1 Main characteristics of Earth and Mars 82 Table 4.2 Effi ciency of chemical and nuclear engines 96 Table 4.3 NERVA engine research and development costs 97 Table 4.4 Parameters of the two missions 98 Table 4.5 Payload mass of Mars landers 102 Table 4.6 Comparison of Mars Viking-based Entry, Descent, and Landing (EDL) systems 103 Table 4.7 Major technical challenges 105 xi xii List of Tables Table 4.8 Costs estimates of the landers ($ billions) 108 Table 4.9 Estimated costs of cargo vehicles 109 Table 4.10 Expenditure by the military and space agencies ($ billions) 112 Table 4.11 Top ten weapon-producing companies 113 Table 5.1 Possible targets for interstellar missions 145 1 Introduction Earth is the cradle of humanity, but one cannot live in a cradle forever. (Konstantin E. Tsiolkovsky) Space exploration has always fascinated humankind. It has inspired the works of philosophers such as Lucretius, Kepler, and Kant and mod- ern works of fi ction by Jules Verne, Isaac Asimov, Arthur C. Clark, Fred Hoyle, and Italo Calvino. Th ese works are not only pleasant entertain- ment but also ways to expand our imagination. Th ey allow us to explore human responses to future scientifi c developments and to speculate on how they might develop. In the second half of the twentieth century, space exploration moved away from the realm of pure imagination. Sputnik and Soviet astronauts (beginning with Yuri Gagarin) orbiting the Earth and American astronauts landing on the Moon created an atmo- sphere of optimism. Optimism pervaded science, the public, and the arts, as Stanley Kubrick’s fi lm 2001: A Space Odyssey explored the possible origins and fate of humankind in space. After the optimism of the 1960s, human space exploration entered a state of fl ux. Humanity’s presence in space centred on suborbital fl ights © Th e Editor(s) (if applicable) and Th e Author(s) 2016 1 G. Bignami, A. Sommariva, Th e Future of Human Space Exploration, DOI 10.1057/978-1-137-52658-8_1 2 The Future of Human Space Exploration and short-term residence on the International Space Station. Paraphrasing Tsiolkovsky, humanity still lives in the cradle. Space agencies have been conducting robotic space exploration with great success. Many think of scientifi c research as space exploration’s main goal. Th ey are losing sight of other equally important goals: those of an economic, commercial, or cultural nature.And, in the longer term, spreading out into space may perhaps guarantee the survival of the human race. As physicist Stephen Hawking once said: Th e long-term survival of the human race is at risk as long as it is confi ned to a single planet. Sooner or later, disasters such as an asteroid collision or nuclear war could wipe us all out. But once we spread out into space and establish independent colonies, our future should be safe. As there isn’t anywhere like Earth in the solar system, we would have to go to another star. Th is book develops a scenario for human space exploration.