Beyond Earth: Our Path to a New Home in the Planets

From a leading planetary scientist and an award-winning science writer, a propulsive account of the developments and initiatives that have transformed the dream of space colonization into something that may well be achievable.
 
We are at the cusp of a golden age in space science, as increasingly more entrepreneurs—Elon Musk, Richard Branson, Jeff Bezos—are seduced by the commercial potential of human access to space. But Beyond Earth does not offer another wide-eyed technology fantasy: instead, it is grounded not only in the human capacity for invention and the appeal of adventure but also in the bureaucratic, political, and scientific realities that present obstacles to space travel—realities that have hampered NASA’s efforts ever since the Challenger disaster.
 
In Beyond Earth, Charles Wohlforth and Amanda R.Hendrix offer groundbreaking research and argue persuasively that not Mars, but Titan—a moon of Saturn with a nitrogen atmosphere, a weather cycle, and an inexhaustible supply of cheap energy, where we will even be able to fly like birds in the minimal gravitational field—offers the most realistic and thrill­ing prospect of life without support from Earth.

(With 8 pages of color illustrations) 

Introduction
THE WAY OFF THE EARTH
 
 
Someday, people will live on Titan, the largest moon of Saturn. Their energy will come from burning the unlimited supply of fossil fuels on its surface and their oxygen from the water ice that forms much of Titan’s mass. The nitrogen atmosphere, thicker than the Earth’s, will protect them from space radiation and allow them to live in unpressurized buildings and travel without spacesuits, in very warm clothes with respirators. They will go boating on lakes of liquid methane and fly like birds in the cold, dense atmosphere, with wings on their backs.
 
This will happen because, at a certain point, it will make sense. Today, the cold, gloomy Titan skies are unappealing and impossibly distant. We do not yet have the technology to put people on Titan. But the technology is coming at the same time the prospects for the Earth are getting worse. In earlier times, human beings struck out for strange and dangerous new places when their homes became intolerable. If humanity doesn’t change course on this planet, a new world free from war and climate upheaval could someday draw colonists to Titan in the same way.
 
The technology required for a space colony is already visible. The largest barriers are institutional. An indifferent political establishment. A space agency, NASA, with a culture that squelches dissent and that lacks a coherent goal for human spaceflight. News media that have sold the public a false understanding of the real challenges of space exploration. Going to another planet will be difficult and, without breakthroughs, unacceptably dangerous.
 
But the ingredients for a space colony are coming together. Experience building space vehicles has spread to many countries and private industry. An Internet-spawned innovation culture that knows how to make new things fast has turned its attention to space. The concepts needed to get us there have been thought out already.
 
When the moment comes, it won’t be the first time human beings have embarked on a voyage that seemed impossibly difficult, expensive, and technically challenging. Our kind repeatedly built new societies in places so remote as to forbid return. When we do it again, we’ll probably have reasons similar to those they had then.
 
As authors, we have investigated science and technology as well as culture and the environment to construct our scenario about space colonization. We have pondered the fundamental issues facing humanity: our response to technology; our will to explore, expand, and consume; and how we treat one another and treat the world we already have. The most important ingredient for space colonization is the human animal: our cellular response to cosmic radiation, our psychological ability to travel for years through nothingness, and our ecological fitness for a new landscape where no organism has lived before (at least no organism we know of). What are we? How far can we go?
 
Scientists we interviewed often asked if we were writing science fiction or journalism. We never intended to write a work of imagination, but a skeptic would never have predicted what has already happened. We visited a rocket factory floor where private space industry workers were sewing astronaut suits that Captain James T. Kirk would have been proud to wear. Our scenario is not based on a love of cool inventions and inspiring visions. It relies on our knowledge of people’s tendency for dumb decisions, selfish drives, and messy politics. Recognizing these predictable truths makes it easier to see how technology could unfold, and more interesting and funnier, too.
 
We’ve had tremendous fun thinking and arguing about how this will happen. The work developed while we laughed together for many hours on Skype, Amanda at her office or kitchen table in Los Angeles and Boulder and Charles in a home office facing his snow-buried boat in Anchorage or in the Alaska wilderness.
 
Amanda works with space technology every day. She has practiced to become an astronaut and has managed equipment to capture the scenery of a world on the other side of the solar system. She has also navigated the bureaucracy of big science, a universe of meetings, travel, and egos like any modern organization. Laboring over the myriad details of new ideas, she has helped make the miracle of space exploration real.
 
Charles spends summers off the grid on an Alaskan beach and in winter he cross-country skis almost every day. His books seeking to understand the fate of the planet have taken him to the Arctic pack ice with Eskimo whalers and to a Cambridge, England, aviary with supersmart birds.
 
We’re complementary opposites. Amanda brings the science and the wonder, but also an awareness of how technology unsteadily unfolds. Charles brings the skepticism of one who has studied human tragedy on Earth, but also the optimism of one who loves the nature in us all. Amanda would eagerly accept a one-way ticket off the Earth to fulfill her drive for adventure and her vision for the future. Charles can hardly sit still through a red-eye flight and cannot imagine saying good-bye to the snow, sea, and fresh air of this world.
 
We’ll never be rich enough to send everyone off to another celestial body, but it isn’t hard to imagine a day when governments or the very rich begin thinking of a spaceship as a lifeboat—or an ark. People are already thinking that way. In 2008, the Svalbard Global Seed Vault opened, deep inside a frozen mountain on an island halfway between Norway and the North Pole, to preserve millions of plant lines in case of disaster or apocalypse. An off-world colony would likewise shield a store of human genes out of the way of any earthly harm.
 
But, unlike seeds, human beings don’t stay the same when you put them in safe storage. An extraterrestrial colony might begin as an annex to Earth, preserving our species, but it would develop into a world of its own, with its own culture, government, and future. Within a generation the Earth could be a foreign place to children born under an orange sky. For them, the smell of recycled air, not fresh breezes, would carry the nostalgic sense of home.
 
We envision their sky as orange because our scenario for this future leads us to Titan. Why Titan? We have screened each of the places colonists could go to find one where the requirements of human safety and sustenance can be met without direct support from Earth and without end. The process of constructing a scenario led us to this wet, energy-rich object in the outer solar system.
 
We aren’t exactly predicting that a colony will be built there, and we certainly don’t know when it will happen. A scenario is a way of organizing an investigation of the future, not a prediction. This powerful exercise generates a thought experiment that anyone can run in his or her own mind, using the hard information we provide. As you come with us through this journey into a possible future, you will find all the facts for your own thought experiment to see if your reasoning brings you to Titan, too.
 
The book’s structure reflects this interplay of hard science and intriguing projections. Alternating sections cover reality and the future scenario. Sections labeled “Present” report the technology and ideas that already exist and tell the stories of the real people bringing space closer. Sections labeled “Future” project a scenario that responds to forces and opportunities that seem to us likely, as well as some whimsical predictions. The book interweaves these two modes to create an integrated picture of what’s known and where that knowledge could lead. Readers are free to reach their own conclusions.
 
Building a self-sustaining space colony is several decades and technology steps away. But many space scientists and engineers think about it, because it represents the kind of adventure that brought them into the field in the first place. And because it raises fascinating questions about today’s technology, research, and space industry. Indeed, the goal of moving people to a new planet is the strongest justification for a manned U.S. space program.
 
We’ve started with the current state of space science, then asked how we could get to another celestial body and build a colony there, where we would go, and why it might really happen. To be credible, the scenario must respond to these three questions—how, where, and why—with answers that are based in today’s reality. That’s why the book uses alternating sections: so the present can inform the future for each of the three questions.
 
The question of how addresses the technology of both advanced propulsion and the design of conventional spacecraft as they become commonplace. As the business of spaceflight becomes assimilated into our everyday lives, economics holds the key. The commercial spaceflight industry is transforming our sense of possibility. Using Silicon Valley’s money and innovative confidence, it will soon bring mass space products to the market. This industry looks something like the computer business did when Steve Jobs and Bill Gates were leaving their garages: ready for a rapid spread beyond the confines of expensive, centralized government projects and into making space travel safe, repeatable, and affordable. As that happens, the cost of lifting materials to weightlessness will fall dramatically, transforming the practicality of every space endeavor.
 
The question of where brings out the many insights of planetary science, as well as space health, psychology, reproductive issues, and the interlocking needs of energy, shelter from radiation, and adaptation to low-gravity life. Colonists need a place they can survive and support themselves, indefinitely.
 
This “where” question has two steps: asking what human society needs for survival and picking the best spot in the solar system to meet those needs. Titan’s hydrocarbon hills and lakes can provide unlimited fuel. Water and its constituents of hydrogen and oxygen make up half of Titan’s mass. With water and energy we can make food, process materials, and power cities.
 
That leaves the question of why, which asks for plausible reasons to leave the Earth permanently.
 
This isn’t a Lewis and Clark journey of discovery, probing the unknown and returning home to fame and glory. Space colonists are more like the anonymous pioneers who headed west in covered wagons to build homesteads. The trip won’t be fun and they aren’t coming back. Life will be hard and dangerous for at least the first generation. Some exceptional people might be willing to go merely to be the first, but creating a colony will require more than adventurers. A colony will need people, a lot of them, with specialized abilities and the resolve to settle and build. Most of all, it will need a sponsor willing to pay the enormous cost of launching the endeavor. In some ways, the “why” question is the biggest of all.
 
Often, the colonies of the past justified their cost either by sending something of value back to the mother country or by giving the colonists themselves a way to get away from something bad back home. As for the first reason—making money—the business case for living in space remains murky. Space mining could produce materials that don’t exist on Earth or are extremely rare here. Heat-shocked graphite asteroids laced with diamonds. Moon deposits of a helium isotope, He-3, implanted by the solar wind, that could power fusion reactors.
 
But fusion reactors don’t exist yet and interplanetary payloads currently are worth more than diamonds (and we probably don’t need that many diamonds anyway). Indeed, no resource we know of justifies the cost of a mission, let alone a colony. The business proposition for colonization could improve with cheaper space travel, a big find by space prospectors, or a new technology that requires materials not found on Earth. For us as authors, these possibilities remain hazy, so in our scenario we have chosen another motivation to drive space colonization: the need to get away from the Earth.
 
Human beings can’t go west anymore. Our planet is full. Our personality as a species suggests some of us won’t put up with that situation indefinitely. True, the human family is mixed. Some stay home, fix what doesn’t work, or learn to live with nearly intolerable political or environmental conditions. But others break away to make new places, never planning to return. We spread. We have done so since leaving Africa to populate Europe, Asia, and the New World, and since then we have repeated the process over and over again.
 
The trends in environmental and political conditions on Earth are as important a part of a scenario for space colonization as the technology story, and an important part of understanding ourselves. Along with learning how our bodies respond to space, we need to predict how our societies will respond to a deteriorating environment, increasing political and religious conflict, and widening wealth disparities.
 
The inspiring and discouraging qualities that make people such interesting animals are already mixing to create the movement toward space. Billionaires are building spaceships to go farther than any man or woman has gone before, at the same time as they make money selling tickets for joyrides beyond the atmosphere.
 
We’ve met brilliant young engineers at commercial space companies who are driving down the cost of access to space. They are putting in long hours to make spaceflight a part of everyday life and thinking several steps beyond. They don’t work so hard just for a paycheck. These young aerospace workers speak the language of Star Trek, attacking huge technical challenges with the dexterity and attitude of hackers. They’re unfamiliar with failure and utterly sure they are on the way to space.
 
Spending time with these people, it’s not hard to imagine a day when a huge spaceship will prepare for departure from the end of a long, retractable corridor connected to a commercial space station orbiting the Earth. The scenario may sound like science fiction. But doesn’t the future often sound like science fiction—until it suddenly arrives?