Why Do People Want to Settle Space?

And how would their answers affect their decisions there?

I was asked a great question on Twitter this week in response to my recent interview in Nature:

Philip Ball asked for “an analysis of the motivations for human space exploration”. Well, Philip, thanks for the question, and I hope you don’t mind this change in venue. Also, my book, Off-Earth: Ethical Questions and Quandaries for Living in Outer Space, spends the whole of Chapter 2 on this topic, if you want an even more in-depth exploration of these ideas.

Philip’s thread is absolutely correct that examining our motivations for why we want to explore, develop, and/or settle space is a crucial first step for figuring out how to conduct these activities ethically. (One might also argue that the crucial zeroth step is asking whether we should conduct these activities at all; that’s Chapter 1 of Off-Earth.) If you ask one hundred people working in space science or industry what their motivations are, you’ll get one hundred different answers— or more— but there are some broad themes we can identify (several of which are mentioned in Philip’s thread). In no particular order:

Survival

Eventually, a billion or so years from now, the aging Sun will expand, making the Earth uninhabitable. In fact, our planet is very likely to become uninhabitable to humans some time before then. If we have figured out how to live on other planets (or in free-floating space stations) before then, we improve our species’ chances of outliving our home planet.

This is the “don’t keep all your eggs in one basket” argument, and it’s the one I find most compelling on this list. However, it’s also frequently used to dismiss any criticisms of space settlement advocates’ plans, like so: Why are you criticizing the solution to human extinction? Don’t you want to save the human race from extinction?! This extreme utilitarianism can be used to justify a lot of unethical behavior in the process of preventing a hypothetical existential threat.

Science

There are plenty of scientific reasons to study space (you can trust me on this, I’m a doctor— of studying space). And it’s very useful to be able to study parts of it up close. But there’s an ongoing debate over whether we need human scientists to be present for that “up close” research, or whether we can perform these investigations more safely and efficiently with robots. Human space settlers would undoubtedly advance several fields of science (planetary science, human physiology, etc.) just by attempting to stay alive in space, but it’s not clear whether science is enough of a justification for the risks and costs of settlement.

Profit

This is the motive driving the rapid growth of today’s commercial space industry— the chance that humanity’s first trillionaire will be made in space. And if you subscribe to the idea that capitalism breeds innovation, building a space economy may seem appealing even if you’re personally more invested in another motive on this list and aren’t trying to become a space trillionaire yourself.

But history (and the modern world) teaches us that organizations motivated by the pursuit of profit can and will produce a lot of harm along the way, especially in the absence of strong regulation to protect things like the environment, or workers’ rights.

Progress

Related to the profit motive is the argument that we must continue to expand and access new resources as a species, or else we’ll face the dreaded fate of stagnation. Our current economic system, which is so focused on growth as a measure of success, is obsessed with never-ending progress. But we live on a planet with finite resources, so outer space and its resources are an appealing solution to that dilemma.

There’s also a version of this argument that claims that human culture will deteriorate if we do not have a literal frontier on which to expand. This kind of thinking is reminiscent of Frederick Jackson Turner’s frontier thesis, stated in 1893, which claimed that the character of the U.S. as a nation was attributable to the existence of the frontier, which in that year had reached the western coast and effectively “closed”. This theory is not only extremely colonial and narrowly focused on the U.S., but it’s no longer accepted by most modern historians.

There are other ways for societies to flourish that don’t involve gobbling up all the land and resources they can reach. I’ll also note that if we stick with this progress argument for settling space, we’ll never learn how to live sustainably within the constraints of an environment, and we’ll just keep spreading across the galaxy like some kind of sentient kudzu. (Or, more likely, we’ll burn ourselves out by using up our local resources faster than we can expand.)

Destiny

Leaning even more heavily into mythological narratives from history is the “destiny” argument, that “our future lies in the stars” and that it is our genetic, or perhaps even spiritual, destiny to conquer the stars.

The spiritual side of this argument dates back at least to Russian cosmism, championed notably by Konstantin Tsiolkovsky (considered one of the fathers of rocket science), who believed that building a civilization in space would allow humanity to reach a state of immortal perfection. And of course, it’s also clearly related to the American myth of Manifest Destiny, the belief that it was American settlers’ God-given right to expand across the continent and spread democracy and civilization. We can see the damage that this kind of belief has caused here on Earth, especially during and after the era of colonization: If we believe that something is our destiny, we assume that we have a right to it, and that any means are justified by this inevitable end.

I recommend Mary-Jane Rubenstein’s recent book Astrotopia: The Dangerous REligion of the Corporate Space Race for a critical dive into this perspective.

Military

I didn’t discuss the military motives for space settlement much in my book, but Philip is correct to add it to the list. Nationalism has been present as a motive in space exploration since the first satellite was launched into orbit, and it’s still present today. Some versions of government space agency PR frame this as a race for prestige— that by demonstrating the scientific and technological prowess to send humans farther and farther into space, countries can flex their reputation muscles on a grand stage.

But even though the Outer Space Treaty of 1967 forbids the placement of military bases or the use of weapons of mass destruction in space, the military advantages of space technology are obviously still a strong motive for governments. I highly recommend Bleddyn Bowen’s book Original Sin: Power, Technology and War in Outer Space for an excellent exploration of the history of this motivation throughout the space age.

So, did I miss any? Have you heard other arguments for human space settlement? How do you think settlement would play out differently if it was driven by these various motives?

Other News

I had the opportunity to chat with Franck Marchis for SETI Live this week. You can find a recording of the livestream on YouTube.

I was also featured (in excellent company) on Next Big Idea Club’s list of five books about living off-Earth.

I’ll be attending the last two days of the National Space Society’s International Space Development Conference this weekend in Frisco, TX. I’m giving a talk on the afternoon of Sunday, May 28 as part of the Living in Space track— come say hi!

I’ll also be moderating a panel on crew selection for the Interstellar Research Group’s 8th Interstellar Symposium in Montreal on July 10-13.