The End of Astronauts

Why Robots Are the Future of Exploration

Donald Goldsmith, Martin Rees

• Publisher: Belknap Press
• Year: 2022
• ISBN:
  9780674276215
• Topic: Physical Sciences
• Subtopic: Space Science

A History Today Book of the Year A world-renowned astronomer and an esteemed science writer make the provocative argument for space exploration without astronauts. Human journeys into space fill us with wonder. But the thrill of space travel for astronauts comes at enormous expense and is fraught with peril. As our robot explorers grow more competent, governments and corporations must ask, does our desire to send astronauts to the Moon and Mars justify the cost and danger? Donald Goldsmith and Martin Rees believe that beyond low-Earth orbit, space exploration should proceed without humans.In The End of Astronauts, Goldsmith and Rees weigh the benefits and risks of human exploration across the solar system. In space humans require air, food, and water, along with protection from potentially deadly radiation and high-energy particles, at a cost of more than ten times that of robotic exploration. Meanwhile, automated explorers have demonstrated the ability to investigate planetary surfaces efficiently and effectively, operating autonomously or under direction from Earth. Although Goldsmith and Rees are alert to the limits of artificial intelligence, they know that our robots steadily improve, while our bodies do not. Today a robot cannot equal a geologist's expertise, but by the time we land a geologist on Mars, this advantage will diminish significantly.Decades of research and experience, together with interviews with scientific authorities and former astronauts, offer convincing arguments that robots represent the future of space exploration. The End of Astronauts also examines how spacefaring AI might be regulated as corporations race to privatize the stars. We may eventually decide that humans belong in space despite the dangers and expense, but their paths will follow routes set by robots.

CHAPTER 1

Why Explore?

Do we need humans in space? Many members of the public reply with a definitive answer: Of course we do! A variety of assertions underlie this nearly automatic conclusion: “Curiosity is in our DNA.”¹ “Humans have evolved to explore.”² “If we cease our exploration, we shall cease to be truly human.”³ Humans working in space “demonstrate American military superiority”⁴ (a theme that President Donald Trump repeatedly simplified by asserting that “America will land the first woman on the moon—and the United States will be the first nation to plant its flag on Mars”).⁵ “As pioneers, we seek to blaze the trail for others, establishing a presence that leads to economic progress and broad societal benefit.”⁶ “We must inspire young people and future generations, which only astronauts can do.”⁷ “Mars beckons us.”⁸ “Mars is within our grasp.”⁹ “When humanity is living and working on Mars, it will change everything.”¹⁰ “We must send humans into space to prove that we can.” The last of these is an argument embraced by President Kennedy in his September 1962 speech that urged the nation to send astronauts to the moon:

But why, some say, the moon? Why choose this as our goal? And they may well ask why climb the highest mountain? Why, 35 years ago, fly the Atlantic? Why does Rice play Texas? We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too.¹¹

The preceding quotations, drawn from dozens of similar ones made both by ordinary people and by experts in various fields, primarily emphasize the emotional basis for supporting the human exploration of space. They also focus attention on the public’s chief target in space today, the fascinating planet Mars. Chapter 5, which provides a detailed discussion of the prospects for exploring Mars with robots or humans, includes an examination of the scientific arguments for and against sending astronauts there, which hinge on whether humans can explore much more efficiently than robots—an issue with an obvious past answer (yes!) that remains arguably correct today but provides at best a highly uncertain prediction for the future. Among other uncertainties, we know not when astronauts may reach Mars, nor which countries will send them, nor whether the first “Marslings” will be funded by governments, corporations, or rich individuals.

To some, these distinctions have little importance. Our emotional preference for human rather than robotic explorers rests on sentiments that each of us formed before we ever attempted to use reason as a guide. These attitudes will persist, hardly capable of change or refutation whatever outcome we may desire. Nevertheless, claims for the superiority of astronauts over robots deserve closer examination through several approaches.

First, to paraphrase the philosopher James S. J. Schwartz, the desire to explore is not our destiny, nor in our DNA, nor innate in human cultures.¹² The first assertion has only mysticism in support, the second has no genetic evidence, and the third encounters negative evidence around the world. If sending humans to Mars were “our destiny,” we would have no reason to hurry down this path, as many insist we must, since we would be sure to get there eventually. If our DNA someday revealed a genetic bias toward exploration, this could have resulted from natural selection in the descendants of those who had engaged in exploration and survived. And while some cultures have proven enthusiastic adventurers and explorers, many others have not. For example, Polynesians of past centuries were fearless explorers, while their Chinese contemporaries found satisfaction remaining within the Middle Kingdom.

Second, we do not need to vanquish our challengers in a race to Mars. Competition between nations motivated the push to send humans to the moon; the fifty years after that have shown that a rational exploration program would have made far more sense and yielded far more useful results. The imperative to “beat the Russians” to the moon opened the funding floodgates for the Apollo program, which might never have gotten off the ground had there been no “space race,” to use the common term from the 1960s. Both rational examination and simple common sense suggest that the best way to go to Mars would proceed from a worldwide effort, not only because such an effort would have positive implications for our civilization but also because it would offer a greater chance of success. Unfortunately, such an effort may prove no more likely now than its moon equivalent did fifty years ago. As happened then, a nation may undertake the challenge in order to show its supremacy in space by planting its flag on Mars. In addition, unlike the situation of the 1960s, private funding may undertake the challenge to reach Mars first, thanks to a willingness to accept much higher risks than most nations would, including the possibility of much less expensive one-way journeys (plenty of volunteers already exist). Either pathway for sending humans to Mars will involve tremendous difficulties and expense—more than those envisaged by wealthy individuals whose past history might lead them to believe that they can overcome anything.

A multinational effort—or, even better, a multinational effort that received substantial funds from individuals rather than taxpayers—not only would make more sense but also could inspire the better angels of our nature (though this consideration alone hardly justifies the mammoth effort). Some supporters of astronauts emphasize the “soft power” that their achievements will generate for democratic governments, a proposition that is difficult to confirm and would be subject to countereffects from the possibilities of catastrophe that inevitably accompany all space exploration.

Third, humans on Mars will not change everything. Even if we united humanity to accomplish this task, our problems on Earth will remain much as they are today. This argument reappears (in spades) in Chapter 7’s discussion of giant colonies in space, whose supporters imagine improved societies, freed from the constraints that weigh us down on Earth. A far more likely outcome would demonstrate that humans bring their problems with them no matter where they go.

Fourth, although astronauts do help to inspire students as well as adults to learn about science, they are hardly necessary to achieve this result. The landing of the Perseverance rover on Mars in 2021 demonstrated that spectacular images and astonishing scientific results can elicit a powerful response. Today’s generation of students, who possess far greater knowledge and acceptance of virtual reality than their predecessors, have correspondingly superior abilities to project themselves mentally to other worlds without losing sight of where they are.

Fifth, in contradiction to President Kennedy’s words six decades ago, the argument that we should accomplish a feat in order to prove that we can makes no more sense than climbing Mount Everest simply because it is there. This justification works only for those who regard planting the flag as the prime reason for going to Mars.

The preceding discussion addresses only the most commonly offered justifications for astronauts. A complete treatment would have to deal with the wider range presented by the science writer Oliver Morton, who wrote that people may want to go to the moon not only to mine its resources but also for “tourism, self-gratification, inspiration, ego jousting, the denting of the universe, preserving and enhancing the future of humankind, having fun, showing off, and experiencing the sublime.”¹³

Surveys of public attitudes tend to show that three rationales for supporting human spaceflight rise highest:

• Humans in space can do more, and more efficiently, than robots can.
• Humans must satisfy their impulse to explore new frontiers.
• Humans in space add to our understanding of the cosmos and ourselves.

These three arguments draw on different types of explanation for human activity. The first assesses human abilities, the second draws on our inner urges, and the third posits a desirable goal for our civilization. Before turning to additional motivations for human spaceflight, we may note that the discussion throughout this book centers on disproving the first assertion, which grows steadily weaker as time moves forward; focuses less on investigating the second as possibly determinative of the issue of astronauts versus robots; and wholeheartedly adopts the third, which supports the use of automated as well as human explorers.

We should note that even though astronauts who venture to Mars would take heroic risks, we would make an error in calling them “explorers” and comparing them to the famed European explorers of the fifteenth and sixteenth centuries. Long ago, the first humans to travel to distant regions entered true terra incognita, lands unknown to them before their arrival. Astronauts who reach Mars will touch down on regions previously explored by robots in detail (including, in all likelihood, the analysis of samples returned to Earth) and will be able to communicate with Earth. (At least they are likely to avoid the shock of discovering native inhabitants who already knew all about their “newfound” land.)

If the United States and other countries decided to prioritize sending humans to Mars to the same degree as the Apollo program, few would disagree that astronauts could reach Mars well before 2050, and probably by 2040. However, the prevailing political and commercial reality creates a large gulf between what can be done and what will be done. Consider that the Concorde, the first supersonic airliner, which entered service four months before the first Apollo landing on the moon, made its final flight almost twenty years ago, with no detailed plans for any successor.

NASA’S JUSTIFICATION FOR HUMAN SPACE EXPLORATION

Those who turn to the NASA website “Beyond Earth: Expanding Human Presence into the Solar System” will find that the section “Why We Explore” includes the assertion that “curiosity and exploration are vital to the human spirit and accepting the challenge of going deeper into space will invite the citizens of the world today and the generations of tomorrow to join NASA on this exciting journey.” The site’s “Why Mars?” section ends with this statement:

A mission to our nearest planetary neighbor provides the best opportunity to demonstrate that humans can live for extended, even permanent, stays beyond low Earth orbit. The technology and space systems required to transport and sustain explorers will drive innovation and encourage creative ways to address challenges. As previous space endeavors have demonstrated, the resulting ingenuity and technologies will have long lasting benefits and applications. The challenge of traveling to Mars and learning how to live there will encourage nations around the world to work together to achieve such an ambitious undertaking. The International Space [S]tation has shown that opportunities for collaboration will highlight our common interests and provide a global sense of community.¹⁴

Beyond the unchallengeable assertion that sending humans on long journeys will prove that they can indeed perform them, nothing in this statement distinguishes any benefits of human visits from those flowing from robotic exploration.

PSYCHOLOGICAL ASPECTS OF SUPPORT FOR SPACE EXPLORATION

A complete discussion of the pros and cons of sending astronauts on journeys that range in distance from the few hundred miles needed to reach a comfortable orbit around the Earth through the quarter-million-mile distance to our moon and on to the hundreds of millions of miles to Mars must explore not just the solar system but also the human psyche, in some ways a more difficult proposition. In contrast to a cost-benefit analysis of the different approaches to space exploration, which has the virtue of reliance on numbers, an assessment of the nature and significance of exploration’s psychological and emotional underpinnings remains far more uncertain. Yet a large portion—perhaps the major portion—of our support for space exploration depends on how we feel about particular programs, rather than on the scientific knowledge, mineral wealth, or other visible results that they may produce.

Any examination of humans’ emotional and psychological attitudes toward space exploration should recognize that members of the public often fail to keep in mind the significant differences between human and automated investigators of the cosmos emphasized in this book. When asked directly, many people will insist that humans must or should engage in space exploration, but their reactions, typically springing from emotional considerations, often soften or eliminate the human / robot distinction, so all exploration strikes a positive chord.

In contrast to these feelings, scientists and engineers remain vividly aware of the differences between the two approaches to exploration. Over the decades their efforts have featured two distinct methods, on rare occasion intermingled, for studying the universe. We can send astronauts farther and faster than before, allowing them to reach the closest objects in our solar system and to probe them in person. Or, as we have done repeatedly, we can design and build robots. One type of robot makes journeys to worlds within the solar system, performing far more cheaply...