The big question: Why go to space at all?

Part of my series on countering common misconceptions in space journalism.

To put it bluntly: Why?

I’ve written hundreds of thousands of words about space exploration and humans living on Mars. I believe deeply in the value of this mission and have done so ever since a crafty Dr Zubrin himself thrust a paperback copy of “The Case for Mars” into my 9 year old mitts on an Australian book tour. Clearly a questionable influence!

Personal conviction amongst a tiny minority, however, will only get us so far. Throughout history, space exploration has failed to attract even a weak majority of support among the general electorate, even at the peak of the Apollo program. Lots of humans living in space has never been a lasting national priority and, as a result, hasn’t yet occurred.

Part of the reason for this is expense. As outlined in the blog comparing Mars exploration architectures, conventional exploration modes would require military levels of funding to build even a small base on Mars. Furthermore, I believe it’s very unlikely that space-based manufacturing or mining could be lucrative enough to fund the venture. Fortunately SpaceX has articulated an architecture that can reduce the cost enough that it might just be accessible to regular people. This democratization of space has seen a hugely positive response, such as the initial Falcon Heavy launch. People want to go to space, they just need it to be possible.

To dive into the specifics, let’s articulate compelling arguments for a future involving many humans living in space.

The best extended writing on this topic comes from Dr Zubrin’s recent book “The Case for Space.”

Zubrin gives five reasons: Science, frontier, asteroids, expansionist ideology, and vision. I will summarize these arguments before adding the missing ingredient.

Science! Earth is but a tiny part of the known universe. In our effort to understand the natural world, the answer to many of the really big questions is out there, not down here. Are we alone? How/where did life originate? Can we live elsewhere? How did the universe begin? What does physics look like at really high energies? Are there Earth-like planets nearby? How do black holes work? For the first time in human history, nay, the known history of the universe, the answers to these questions are within the grasp of sentient life.

The final frontier! The challenge of living in space will necessarily create enormous advances in technology. The obvious ones are automation, propulsion, rocket construction, robotics, materials science. Less obvious ones include economics, governance, health, nuclear engineering, and so on. Throughout history, expansions of the frontier have coincided with an efflorescence of invention. Companies and individuals that are well positioned during this period of growth will generate enormous wealth leveraging both prestige, the best engineers, and the best tech.

Asteroids! Dinosaurs are extinct because they didn’t have a space program. Creating and maintaining the technology necessary to protect Earth from a statistically certain extinction event requires a robust and ongoing space-faring civilization. It can’t be maintained with one-off missions built on demand – they would take too long and our continued ability to build them is not guaranteed. Asteroid impact can only be prevented by going out into space, finding them, and taking early preventative action on an ongoing basis.

Expansionist ideology! This chapter really shines, and it changed my mind about a few things. There is a persistent cultural undercurrent that promulgates the dangerous idea that there is a finite carrying capacity for humans on Earth. Ironically, this ideology was first published by Malthus in 1798, in the midst of the same industrial revolution that forever discredited this idea. That is, while agrarian economies prior to the industrial revolution were population limited by the efficiency of photosynthesis and digestion, economies since have been able to provide a much better quality of life for a much larger number of people, a trend that is self-reinforcing and shows no sign of slowing down. The reason Malthusian ideas are dangerous is because they see the marginal addition of humans as a net drain, rather than a net source, of wealth. As a result, they imply that population control, whether through war, immigration restriction, genocide, or forced sterilization, is inevitable. It is not. Expanding human civilization into space creates not only a technological frontier but a compelling repudiation of the idea of finite resources.

Vision! While asteroids and overpopulation can be a bit grim, the vision argument points out that to build a positive future for humanity, people have to be excited by a compelling vision. The future has to be cool. A future where humanity is out living on other planets and giant space stations and exploring the stars is cool. A future where humanity festers on Earth for a lack of worthy challenges and resorts to ancient patterns of tribalism and zero-sum conflict is not cool. Creating a city on Mars can remind a generation that the future is out there – and save our collective souls.

The missing ingredient! What is the single most important thing for unifying humans around a common goal? What is the secret sauce that almost exclusively determines whether a large, unprofitable project lives or dies?

It may sound sappy, but the necessary and sufficient component is love. Love can explain why Wikipedia doesn’t suck. As Antoine de Saint-Exupéry explained in his book “Citadelle,”

One will weave the canvas; another will fell a tree by the light of his ax. Yet another will forge nails, and there will be others who observe the stars to learn how to navigate. And yet all will be as one. Building a boat isn’t about weaving canvas, forging nails, or reading the sky. It’s about giving a shared taste for the sea, by the light of which you will see nothing contradictory but rather a community of love.

This ideal motivates my terraformed Mars project, which you can see on Twitter. When people can see Mars not as a barren frozen irradiated bombarded miserable lonely distant poisonous hellscape, but as a place of beauty and a home, the rockets will build themselves.


Let’s do it!

20 thoughts on “The big question: Why go to space at all?

      1. It’s not safe to assume that no one would waste their asteroid by crashing it into Earth, given how much we spend on similarly omnicidal systems down here already. It needs regulation, saying that if you want to live in an Earth-crossing orbit, or own propulsion capable of putting you in an Earth-crossing orbit, you have to be small enough not to kill more than a few million people. And it needs institutions that can be relied on to ensure compliance.


  1. The most import reason to go into space is our innate responsibility to continue the phenomenon of “life”. Life may not exist anywhere else in the universe and we, as creatures of Earth, may be the only example of energy and matter that is aware of itself.


  2. It’s compelling to me, although the lack of more concrete push and pull factors is going to slow it down or stop it for a long while yet. Prior frontiers were built on lucrative opportunities and heavy population pressure, and neither of those are really there in space – there is no “space tobacco” to pay for it all.


    1. Before 1492, had you asked a European to tell you what was so valuable in an unknown land, s/he couldn’t have told you. One must simple explore first before one can know if there are economic incentives awaiting.

      Even in LEO, there is a resource awaiting, microgravity… which for a semiconductor / display manufacturer would be pure gold: No tool sag. Seriously, gravity sucks. Our tools and even our work pieces sag under the load and limit the resolution over distance, and thus the size of work pieces, and ultimately then, the economy of scale (of the work piece). I foresee high tech fabs of the future in space.

      Obviously, the product needs to have a VERY high value to make it profitable given transport and support costs. Integrated opto-electronics down to the atomic level precision at industrial scale will provide it.

      I would expect, as we develop such space based industries, new opportunities will arise that today are simply not within our ken.

      Liked by 1 person

      1. That’s not really true. By the time Columbus was proposing his expedition, there had been decades of increasingly lucrative European expeditions along the coast of Africa, and a very lucrative destination already in mind (the spices and other trade goods of the Far East). Columbus wasn’t proposing an expedition into the open ocean that would somehow make its money back later through vague means*.

        * On a side-note, he apparently would switch between “this will give us a shorter route to the riches of the Far East” and “this will give us access to new lands and islands to exploit like the Canary Islands”, depending on the audience receiving his pitch.


      1. I looked it up and tried to post a comment with the URL. Does the software not allow that?


  3. I think that if we wish to make a compelling argument to others, we must first admit the hardest truth – there isn’t a GOOD reason for manned expansion into space at this time.

    Science? Much bigger bang for the buck with unmanned missions. Orders of magnitude bigger.

    The challenge of the final frontier? We’d do better by expanding in currently unused territory here on Earth – the oceans in particular. As stupidly expensive as seasteading is, it’s still orders of magnitude less stupidly expensive than spacefaring. And we have a lot more experience with the necessary technologies.

    Asteroids? We can get MUCH better survival chances with asteroid searches and very affordable missions for asteroid deflection. And for extinction level threats in general, underground habitats offer much better chances of humanity survival than the equivalent spending in space habitats. The “Dr. Strangelove” solution is basically doable with far less technology risk and uncertainty than trying to figure out how to do an Ark in space (Mars or wherever).

    Expansionist ideology? We’d do better by first expanding into vast currently unused territory here on Earth. The oceans in particular, but also underground. Personally, I think the most fruitful expansionist strategy is to combine dense cities on land with massive fleets of ocean-going farming subs. These could use kites above the water for 24/7 power, while cruising under the photic zone so the ocean’s existing ecosystem is unaffected. The point is – the ecological footprint of the massive cities (think Heat Guy J) is offloaded into currently unused oceans, but you don’t need humans to actually be living in the relatively hazardous and annoying environment of harsh oceans.

    Vision? What good is a vision of a privileged lucky few humans getting to explore space while the vast majority of humans stuck on Earth remain stuck on Earth? Is this supposed to be an uplifting vision? A more uplifting vision wouldn’t involve giving up on “festering” Earth. In contrast, expansion into Earth’s own oceans is something that could be accessible to the bulk of humanity living on Earth – not just a privileged lucky few.

    So, let’s admit that there aren’t any GOOD reasons for manned expansion into space. Instead, let’s embrace that fact and furthermore embrace the fact that we humans don’t do things only because they make good sense. We also do things for reasons that are just … well, we just feel like it. Why go to space? Simply because we dream of it. Humans in space captivates our culture more than futuristic visions of humans living in cities here on land or underwater. It’s not logic that compels us to go to space, but desire. And desire isn’t some cold equation.

    Liked by 1 person

    1. One extinction threat leaves all the others in the dust: ourselves. I can’t imagine an omnicidal war sparing a major city just because it’s underground or underwater. I can imagine such a war sparing a city on Mars, because it’s unable to pose a threat to either side. Autarky doesn’t happen easily. You would need to put a nearly insurmountable barrier around a city if you want to make it forgo the advantages of being economically connected to the outside world. I don’t think we can do it on Earth.

      Liked by 1 person

      1. Good point. That kind of threat includes accidental or malicious ones, like AI getting out of control, a hypothetical self-replicating nanotech, or a really serious bioweapon getting out of a lab. Physical separation from Earth might be the best insurance policy – but any threat that could last more than a couple decades requires a truly self-sufficient colony – probably hundreds of thousands of people (to build and maintain the tech that keeps people alive in a hostile environment) and thousands of species.


  4. “the dangerous idea that there is a finite carrying capacity for humans on Earth”

    Dangerous or not, it’s true. We cannot be miniaturized to have smaller mass than a proton and still count as humans by any reasonable criteria. The ratio of the masses of Earth and a proton is very large, but it is strictly less than aleph-null.

    If we leave out the miniaturization, and assume that humans are confined to a sphere centered on Earth and expanding at the speed of light, and that the average volume of a human never falls below fifty liters, exponential growth at twentieth-century rates cannot continue for more than about three thousand years.

    “they imply that population control, whether through war, immigration restriction, genocide, or forced sterilization, is inevitable.”

    No. Population control will happen somehow. But that doesn’t imply that the means will be on this list of risibly ineffective means. The heyday of genocidal war was also the period of highest population growth in human history. Probably still is if you include human prehistory.

    If you really want population control, you need to do horrible things like eliminate child labor, mandate universal education, provide retirement security that doesn’t depend on having enough children, reduce infant and child mortality to a level where people who want children don’t feel the need for multiple extras to ensure that one survives, make contraception readily available, and give women approximately equal status with men.


    1. 3000 years is a long way off. As you hint, giving women control over their own bodies is adequate to severely crush the birth rate, sufficiently so that within my lifetime I expect the narrative to shift to underpopulation being bad!

      Liked by 1 person

  5. Today I want a Martian space elevator.

    Mars is small enough (i.e. its gravity is weak enough) that a space elevator could be made of real materials instead of needing carbon nanotubes or some other flavor of unobtanium. But there are a number of problems with the idea.

    First, it’s an overwhelmingly large project. That’s not much of a problem for something imaginary, though. I can just shove it farther into the future, when Mars has a population in the millions. Or maybe billions. If it takes hundreds of billions to support the project at a reasonable additional tax rate, or the equivalent amount by other funding mechanisms, then it’s a problem.

    Second, as usually imagined, space elevators are a bad idea. Stuff crawls up them, slowly. It takes a ridiculously long time to get anywhere. Because each payload spends approximately forever on the elevator, if the throughput is appreciably different from zero, it follows that there are more or less infinitely many of them on the elevator at any time. So the size of the most massive part of the cable has to be multiplied by some ridiculously large factor to hold all that weight. That multiplies some large components of the cost, and the whole idea collapses.

    The solution, as I imagine it, is to have the bottom part be a mass driver. The payloads accelerate at the highest g-force that all payloads can comfortably tolerate, and then leave the elevator once they’re clear of the atmosphere. The main tensile elements of the elevator have to be exactly vertical, if it’s at the equator, because they’re under an unimaginable amount of tension connecting the heavy stuff below to the orbiting stuff above. But the mass driver can have a horizontal component. The tensile elements have to all be vertical, but they don’t all have to be in exactly the same spot. Push the fibers apart at geostationary, and they move apart all the way down.

    Third, there’s Phobos. It’s sometimes said that Phobos would run into an elevator eventually. But I’m pretty sure that an elevator doesn’t have to be exactly at the equator. It can be a couple degrees away, and Phobos will always be closer to the equator than it is. But what I want to do is make the elevator out of Phobos. No one knows the exact composition of Phobos, but it appears to be mostly carbonaceous chondrite. It’s basically a mixture of carbon and rock. If you heat up the rock enough to melt it for glass fiber, the carbon will mostly vaporize. It can be made into polymers, if there’s enough hydrogen present, which I think there probably is. Heat is available with relatively little capital, by focusing sunlight with mirrors. I imagine the tensile component of the elevator being made of different materials in different parts. Near geostationary, the mass doesn’t matter. So it would be made of whatever material is cheapest per newton of tensile strength, probably glass fiber. Farther down, the strength-to-mass ratio matters more, so it would be whatever polymers are cheap to synthesize and easy to work with. Near ground level, mass matters a lot, so it would be made of advanced materials, carbon fiber or whatever. Low-grade unobtanium to us now.


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