There Is a Planet B

The Red Planet has long captured human imagination, going at least as far back as the ancient Greeks, who designated it the god of war. In the modern era, once it was understood that Mars was another planet in our system that could be seen through telescopes, it became romanticized by astronomers like Giovanni Schiaparelli and Percival Lowell, generating dreams of canals and life and civilizations — dreams later disappointed by instruments showing it to be apparently lifeless and desiccated.

But no one in history has more popularized the idea of Mars being a suitable place for the expansion of humanity than Robert Zubrin. A nuclear and aerospace engineer and founder and president of the Mars Society [and a contributing editor of this journal –Ed.], Zubrin first proposed his plans for getting to the planet and settling there at the 1990 International Space Development Conference, which I attended. He called the plan “Mars Direct,” to distinguish it from NASA’s more convoluted and less economical plan. His 1996 book based on the concept, The Case For Mars, has become a classic in the literature on the exploration and development of space.

In his latest book, The New World on Mars, Zubrin advances the case further, offering not only a plan for how to get to Mars and settle it, but also a vision for what a human society there would actually look like. The New World that America once was, he writes, was built by millions of ordinary people into “a beacon of hope, a powerhouse of creativity, and a shining example to be developed further by and for all humankind.” Mars offers the same promise, he contends, and if it feels out of reach or impractical — well, pioneers are always first dismissed as dreamers.

How much will it cost to get access to the planet? A core assumption of Zubrin’s book is that Elon Musk’s plans for the settlement of Mars with his new spaceships — the Starship spacecraft and Superheavy booster — will be successful in their cost goals. Perhaps that is a good assumption — after all, these are perhaps the first actual vehicles in history to deserve to be called spaceships. And Musk is building not just the ships, but shipyards to crank them out, like the rapid construction of Liberty ships during the Second World War.

When Zubrin came up with Mars Direct, launch costs were tens of thousands of dollars per pound to get into orbit. Getting anything to Mars was financially daunting — one reason we ended up sending only robots and never returned anything other than data. NASA’s own Mars plans for human exploration were coming up with a price tag of hundreds of billions of dollars per mission, partly due to political imperatives of supporting all of the agency’s centers and stakeholders. Frustrated, Zubrin envisioned a different architecture using existing technology (based on the space shuttle) to provide a more affordable plan. But it would still basically have been what I would refer to as “Apollo to Mars” — sending a handful of NASA employees and returning them.

However, in The Case for Mars, he laid out a plan that, unlike Apollo, would leave infrastructure behind on Mars with each mission, enabling that infrastructure to grow and eventually become first a permanent base and ultimately a settlement. Even back then, he was proposing the utilization of the abundant carbon dioxide in the Martian atmosphere to manufacture methane and oxygen as propellants for returning to Earth, an idea that Musk has since adopted by using those propellants for his new space transports.

Warning to those averse: The cost section in The New World on Mars is heavy on numbers. There are not a lot of equations, but there is a lot of arithmetic, which I didn’t check — it didn’t look unreasonable. In the last decade, the SpaceX Falcon family, and particularly the Falcon Heavy launch vehicle, have already reduced the price of getting a pound of mass to orbit to below a thousand dollars, largely by reusing the first stages. Some of those stages are now approaching twenty reuses. Zubrin makes the plausible case that, at the levels of activity desired by Musk, with full reusability of hardware, the price to orbit could come down to some fifty dollars per pound.

In the 1979 book Disturbing the Universe, the physicist Freeman Dyson tried to provide a cost baseline for space colonization, calculating that the middle-class people settling America from Europe and the Mormons who headed west, who liquidated their assets to do so, spent about the amount of their homes to pull up stakes. Using projected costs of Starship, Zubrin calculates that the cost of moving to Mars might be today’s equivalent: about $300,000, which many with home equity could easily afford.

He also calculates the costs of constructing habitats on Mars (including needed radiation shielding), building farms and growing food (though little discussion of animal protein other than tilapia and chicken — where’s my rib eye, and no bugs please?), and providing life support. In all cases, Zubrin’s goal is to maximize the use of local resources for bulk-mass needs, and to minimize the necessity for terrestrial imports, while recognizing that such a community will always, or at least for a very long time, be dependent on the advanced industrial economy of Earth.

The question, of course, is how the settlers will be able to pay for their needs that cannot be locally manufactured, and it is one to which Zubrin has given a great deal of thought.

First, many potential resources that don’t exist on Mars will be abundantly available in the asteroid belt between Mars and Jupiter, and he makes the case that, for asteroid miners, Mars will become to them what San Francisco was to the “forty-niners” of the mid-nineteenth century. While most of the mineral resources of the belt will go to supporting people living on Mars, there will be some precious metals that will have enough value per mass to be worth bringing all the way back to Earth. Rhodium, for example, is abundant in some asteroids and used for catalytic converters and coating on optic fibers, and is currently priced at several thousands of dollars per ounce. Miners will become sufficiently wealthy to inject their gains into the Martian economy, on which they will be dependent for food and manufactured goods, but also for entertainment and luxuries unavailable in the belt. “Many of the cities of the American West owe their existence to the bonanza they reaped from this phenomenon,” Zubrin writes. “There is no reason Martian cities should not do the same.”

But the most important export from Mars to Earth, he believes, will be in the realm of ideas, particularly intellectual property. Mars will be a harsh place to live, and, as such, necessity there will be the greatest mother of invention in human history, far more so than the Arctic, or any other new environments humans faced since their origins in equatorial Africa. Furthermore, labor will be a scarce commodity, necessitating labor-saving devices, just as occurred in America in the nineteenth century, with steam engines and cotton gins. Another form of labor that will be scarce, as on any frontier, will be women of child-bearing age, crucial to growing the population. Zubrin makes the important point that resources don’t become resources until humans figure out how to use them. Oil, for example, was a useless, nasty, seeping nuisance until someone figured out that it could be refined to replace whale oil, among other things. To deal with their unique circumstances, Martians will have to invent new industrial processes, which may find adaptive use back on Earth, compensated with patent royalties.

Zubrin notes how new forms of propulsion, specifically steam engines for boats and rail, were needed to transform the vast new continent of America, and how similar needs for Martians will also drive new propulsion technologies. Fusion energy from abundant deuterium on Mars will be required both to power Martian industry, agriculture, and homes, and to provide much faster and more efficient space travel. Another form of scarcity will be land to cultivate, which, given the further distance from the Sun, will spur biotech advances to achieve higher efficiency of plant growth.

But just as interesting to Zubrin as economics is the question of how Martians will live, play, and govern themselves. He has long been a proponent of Frederick Jackson Turner’s frontier thesis: that America’s open spaces provided fertile soil for a uniquely American society and governance. As Turner put it in the 1914 article “The West and American Ideals”:

American democracy was born of no theorist’s dream; it was not carried in the Susan Constant to Virginia, nor in the Mayflower to Plymouth. It came stark and strong and full of life out of the American forest, and it gained new strength each time it touched a new frontier.

The colonists, while still under the healthy legal and mental constraints of English common law, were liberated from the still-extant European strictures of feudalism, classism, and aristocracy. Zubrin imagines a similar effect from the open space, plains, valleys, canyons, and mountains of Mars, providing a new outlet for humanity’s striving and thriving.

Along those lines, he argues that liberty, if not necessarily or immediately an export of the New World, will be an important product of it, as it was in Anglo-America. While the “noble experiment” of the United States was a vast improvement over anything that came before in history, it was not perfect, Zubrin notes, and he holds out for the possibility of further advances. He hopes for an equivalent of the Protestant Reformation for education, and an extension of traditional natural rights of life, self-defense, property, and freedom of worship and speech that might arise on the New World, including what he considers improvements in democracy, legal systems, rights to immigrate and emigrate, invention and utilization of resources, and others. There will be another kind of liberty too, though Zubrin considers it mainly for its economic boon: new kinds of sports offered by reduced gravity. “Players will be able to strap wings on their arms and fly like birds,” he writes, and “basketball players will be able to jump three times as high.”

Unsurprisingly, Zubrin considers at some length the possibilities of Martians terraforming their new home. He proposes to increase its temperature a few degrees with nuclear or fusion power, which will start a runaway greenhouse effect as the frozen carbon dioxide sublimes and water melts and vaporizes, gradually increasing the atmospheric pressure and further increasing the temperature. Bringing in plants will produce oxygen, which will allow animals, and eventually even humans, to breathe outside without space suits. It would perhaps take centuries, but not necessarily millennia.

In response to critics who object to colonizing space on the grounds that it is a form of imperialism, and that rocks have rights, Zubrin retorts that “such views are nonsensical.” Imperialists’ mistreatment of native peoples “was evil because the natives were people,” not rocks. “To claim that humans do not have the right to alter Mars because Mars has the right to be unaltered,” Zubrin writes, “is as nutty as claiming that Michelangelo was committing criminal mutilation of marble blocks by chiseling them into statues.”

In the concluding chapter, “The Cause of All Nations” — which would be a tour de force as a standalone essay — Zubrin suggests that Malthusianism and limits-to-growth ideas were ultimately responsible for the last century’s tyrannies, wars, and starvation, and thus for tens of millions of premature deaths. He repeats a theme from throughout the book: that resources are not natural, that they are the product of the ingenuity of humans, which means the ultimate resource is humans and we should be producing as many as possible, on this planet and others.

The book isn’t flawless — few books are. It could have used a better, tighter structure; as it is, there is redundancy, with repetition of several topics in different sections. But more importantly, there is in particular one elephant in the room that Zubrin doesn’t discuss at all, even in the section on bioengineering: the ability of humans to procreate in a lower-gravity environment. We have trillions of person-years of experience on Earth, many thousand person-hours in free fall in orbit, and perhaps a few hundred person-hours in one-sixth of Earth’s gravity on the Moon. We have zero experience with the roughly one-third of Earth’s gravity on Mars, not even with rodents, let alone primates. We have had human pregnancies and births only on Earth, but if we can’t gestate and raise healthy humans in lower gravity, the prospects for human settlement of Mars would seem grim.

Moreover, even if we assume that healthy newborn humans could be raised on Mars, we have no idea if they would be able to visit and function on Earth, with its three times higher pull, or if they would be doomed to spend their existence on Mars, absent serious strength training. Would Martians be taller and lankier than average terrestrial humans?

This seems to be a blind spot also for Elon Musk, who in a sense is working to make Zubrin’s visions real. We won’t be able to know many of the answers to human colonization of Mars until we actually raise some people there — which is ethically problematic, though it shouldn’t be outlawed. But we could begin to understand the gestation issue, at least with rodents, either in a rotating gravity lab or perhaps on the Moon, with the coming reduced costs to get there. If the one-sixth lunar gravity is sufficient for having babies, then the greater amount available on Mars should be as well. As it happens, there is a centrifuge rusting in a Japanese parking lot that was supposed to be sent to the International Space Station for such research, but canceled due to NASA budget cuts almost two decades ago. Fortunately, there are now multiple private plans for rotating stations, but I’m continually amazed that Zubrin and Musk have seemingly not been doing anything to make this idea happen, not even advocating for it (as far as I know).

This is one of the reasons that, for now, I am personally less enthusiastic about descending into another gravity well with perhaps insufficient gravity, after clawing our way out of this one in which we evolved. SpaceX’s Starship, which successfully reached orbit on the day I write these words, thus becoming the most capable rocket on the planet, will in its scale and dramatic cost-efficiency enable the construction of spinning space communities that are not bound to planets.

But for those who can’t shake the Mars bug, there is urgent work left to do. With his daring new book, Robert Zubrin has laid out a compelling blueprint for much of this work, as well as the audacious vision needed to encourage its execution by those who similarly dare. The New World on Mars is remarkable for its vision not only of what we can accomplish technologically, but also of how we can advance humanity and its works into the solar system and — perhaps, physics willing — beyond. Offering hope over despair, it deserves a place on the bookshelf of not just space enthusiasts, but anyone concerned about the future of humanity.