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 modern works of fiction by Jules Verne, Isaac Asimov, Arthur C. Clark, Fred Hoyle, and Italo Calvino. These works are not only pleasant entertainment but also ways to expand our imagination. They allow us to explore human responses to future scientific 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 atmosphere of optimism. Optimism pervaded science, the public, and the arts, as Stanley Kubrick’s film 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 flux. Humanity’s presence in space centred on suborbital flights 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 scientific research as space exploration’s main goal. They 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:
The long-term survival of the human race is at risk as long as it is confined 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.
This book develops a scenario for human space exploration. Scenarios are not forecasts but rather ways to understand the dynamics shaping the future by identifying the primary driving forces at work today. Analyses of such scenarios do not rely on extrapolations from the past. They consider possible developments and turning points, which may or may not be connected to the past. Scenarios allow for qualitative changes not included in quantitative extrapolations of past trends. This is particularly important when analysing scientific and technical progress. Often, forecasts of these events are made obsolete by unpredictable innovations and scientific breakthroughs.
Our scenario examines: (i) the history of human space exploration from its beginning up to now; (ii) its short to medium-term prospects; and (iii) the possible longer-term developments. History helps us to understand better the motivations and constraints—technical, political, and economical—that shaped space exploration. The short to medium-term prospects enable us to identify the driving forces that will shape its next phase. While science and technology define the limits of what is possible: transforming these possibilities into reality depends on the economic and political benefits resulting from human space exploration. The economic benefits fall into three categories: direct effects measured by revenues generated by using space resources and related services and products; consumer welfare effects measured by the benefits to consumers beyond the value they paid for those products and services; and economic effects that arise from the efficiencies generated by those products and services.
Political benefits come in terms of international cooperation and world political stability. International cooperation is a necessary condition for human space exploration: the financial resources required for it are too large for any single nation to afford. If private companies are to seize the opportunities arising from space exploration, certainty over property rights and the uses of space resources are needed. This would involve extensive international cooperation. But we are struggling to find ways to cooperate. We are far from an advanced level of civilization in which international relations are solely based on cooperation and not conflict. Tensions arising from the control of natural resources, economic inequalities, and racial and religious conflicts are among the obstacles to international cooperation. Doubts exist whether we will be able soon to achieve such a civilization.
Despite this note of pessimism, the situation may not be hopeless. Michael Tomasello1 argues that Homo heidelbergensis developed abilities to cooperate through mimicry and gesturing in the search for food. Later on, Homo sapiens expanded cooperative capabilities through common cultural backgrounds centred on conventions and norms. Through these arguments, Tomasello proposes that humans can continue to develop because they can absorb and share knowledge. The human race has thus the ability to find solutions to problems it has itself created, and, through this process, to reach the stars.
To ease reading, all technical details have been placed in footnotes. However, it is not necessary to read these in order to understand the text; they are there for the curious reader who wishes to know more.
Reference
Tomasello M. A natural history of human thinking. Cambridge, MA: Harvard University Press; 2014.
Astronautics is the theory and practice of navigation beyond the Earth’s atmosphere. Isaac Newton established the mathematical basis of astronautics in his treatise The Mathematical Principles of Natural Philosophy. They are embedded in his laws of motion and gravitation. The reactions in a spaceship’s engine produce enormous pressures. They cause the expulsion of gas and/or radiation at high speed in the direction opposite to travel. It is this reaction force that pushes forward the engine and the spaceship attached to it.
Although Newton laid the mathematical foundations for it long ago, astronautics became a science in its own right in the early twentieth century. Starting in 1883, Konstantin Tsiolkovsky theorized many aspects of space flight. He published his most famous work, The Exploration of Cosmic Space by Means of Reaction Engines, in 1903. In this book1 Tsiolkovsky derived the basic formula for rocket propulsion. This formula calculates the final velocity of a rocket from the escape speed of the gases and the initial (including propellant) mass and final (without propellant) mass of the spaceship. In other theoretical works, he studied gyroscopes and liquid fuel rockets; he calculated the escape velocity from a gravitational field; and he analysed the problem of the control of a rocket that moves between gravitational fields.
Tsiolkovsky elaborated the theory of space flight as a supplement to his philosophical inquiries on the cosmos. His works include speculative concepts, such as the industrialization of space and the exploitation of the natural resources to be found there. Indeed, he was the first theorist to support human space exploration. His works influenced generations of scientists and astronautical engineers from Europe, Russia, and the United States. During the twentieth century, advancements in astronautics and astronautical engineering2—the practice of navigation beyond the Earth’s atmosphere—made possible the exploration of the solar system, including human space exploration. As Wernher von Braun once said: “The rocket will free man from his chains: the chains of gravity that still tie him to this planet. The gates of heaven will then be open.”
Below we will retrace the steps of human exploration of the solar system up to the present day. This will help us to understand the motivations and the constraints that shaped it. Analyses of political, economic, and cultural environments also help us to glimpse the short to medium-term developments.
2.1 The Golden Age of Human Space Exploration: 1957–1973
Human space exploration reached its peak in the late 1960s and early 1970s, driven by competition for power among nation-states. Under pressure of geopolitical competition, the United States and the Soviet Union created vast national space programmes. Sputnik and an orbiting capsule with an astronaut (Yuri Gagarin) created panic in the United States. In response to the challenges posed by the Soviet Union space programmes, the American military establishment proposed that it take the lead in meeting these challenges. But President Eisenhower, fearing the entry of the military-industrial complex, decided that “space was to be used only for peaceful purposes.” He proposed the National Aeronautics and Space Administration (NASA) to Congress, which it promptly approved. NASA thus became the titular owner of all US space programmes.
In 1961, the young President Kennedy gave his famous speech to Congress, which can be summed up in three words: “man, moon, decade.” But neither the President nor NASA knew how to achieve that goal. The staff at NASA were in a complete panic, but the pride inherent in fulfilling their President’s commitment was a potent stimulus. Although Americans did not embrace von Braun because of his Nazi Party membership, he did become the central figure in the Apollo programme. Under his guidance, assisted by engineer Rocco Petrone,3 NASA developed the Saturn V rocket, a modified version of the Jupiter rocket. Von Braun later called the Jupiter “an infant Saturn.” Saturn V became the cornerstone of the Apollo programme, and it remains today the most powerful rocket ever built, and the only one to have carried humans beyond Earth orbit.
At first, von Braun thought of assembling various modules (the command/service module and the lunar excursion module) in Earth orbit. Space shuttles would bring the modules into orbit. A second Saturn rocket would then take them to the Moon; however, two Saturn V rockets would increase costs and might cause delays in the mission. So NASA engineer John Hubolt suggested the lunar orbit rendezvous (LOR) mission mode.4 With LOR, a Saturn V rocket first inserts the modules into low Earth orbit and then propels them into lunar orbit using the last stage of the rocket. The lunar landing mission starts from lunar orbit, so only one rocket is used instead of two. A fierce debate convinced von Braun and NASA to adopt this solution in 1962. Undoubtedly, the decision to use LOR was vital to the manned landing on the Moon by the end of the decade.
This solution saved time and money, though NASA paid a high cost: it discarded the assembly of the modules in low Earth orbit and the related infrastructure, which constituted the core of a space station. This had important consequences for longer term plans for human space exploration. To meet the schedule imposed by Kennedy, NASA lowered the safety standards of the missions. This eventually caused headaches. During the first lunar landing mission, the on-board computer failed. With Neil Armstrong manually piloting it, the landing module was set down on the Moon with only a few seconds of fuel remaining. Even more serious was the case of the Apollo 13 mission, which took place a year later: an oxygen-tank explosion made the service module unusable during the cruise phase to the Moon. The astronauts instead occupied the lunar landing vehicle, uncomfortable but serviceable, and so returned safely to Earth. In retrospect, it was only with considerable good luck that, between July 1969 and December 1972, 12 American astronauts set foot on the Moon.5
Kennedy’s 1961 speech led the Soviet Union to create its own programme6 for landing astronauts on the Moon. But the programme suffered from two disadvantages. The first was the slow development of the computer industry in...
