We just published an interview: Zach Weinersmith on how researching his book turned him from a space optimist into a “space bastard”. Listen on Spotify or click through for other audio options, the transcript, and related links. Below are the episode summary and some key excerpts.

Episode summary

Earth economists, when they measure how bad the potential for exploitation is, they look at things like, how is labour mobility? How much possibility do labourers have otherwise to go somewhere else? Well, if you are on the one company town on Mars, your labour mobility is zero, which has never existed on Earth. Even in your stereotypical West Virginian company town run by immigrant labour, there’s still, by definition, a train out. On Mars, you might not even be in the launch window. And even if there are five other company towns or five other settlements, they’re not necessarily rated to take more humans. They have their own oxygen budget, right?

And so economists use numbers like these, like labour mobility, as a way to put an equation and estimate the ability of a company to set noncompetitive wages or to set noncompetitive work conditions. And essentially, on Mars you’re setting it to infinity.

- Zach Weinersmith

In today’s episode, host Luisa Rodriguez speaks to Zach Weinersmith — the cartoonist behind Saturday Morning Breakfast Cereal — about the latest book he wrote with his wife Kelly: A City on Mars: Can We Settle Space, Should We Settle Space, and Have We Really Thought This Through?

They cover:

• Why space travel is suddenly getting a lot cheaper and re-igniting enthusiasm around space settlement.
• What Zach thinks are the best and worst arguments for settling space.
• Zach’s journey from optimistic about space settlement to a self-proclaimed “space bastard” (pessimist).
• How little we know about how microgravity and radiation affects even adults, much less the children potentially born in a space settlement.
• A rundown of where we could settle in the solar system, and the major drawbacks of even the most promising candidates.
• Why digging bunkers or underwater cities on Earth would beat fleeing to Mars in a catastrophe.
• How new space settlements could look a lot like old company towns — and whether or not that’s a bad thing.
• The current state of space law and how it might set us up for international conflict.
• How space cannibalism legal loopholes might work on the International Space Station.
• And much more.

Producer and editor: Keiran Harris
Audio engineering lead: Ben Cordell
Technical editing: Simon Monsour, Milo McGuire, and Dominic Armstrong
Additional content editing: Katy Moore and Luisa Rodriguez
Transcriptions: Katy Moore

Highlights

A potted history of space exploration

Zach Weinersmith: Yeah. Let me give you a kind of potted history up to now. One way to think about all this is that it’s only in the late 19th century that it becomes clear you could even get to orbit. That’s because we’ve managed to liquefy these gases that are used as propellant. You know, rockets have been around for centuries, but they’re just kind of like a crappy military thing that’s not as good as just like setting mortars throughout most of history. And then we hit the scientific chemistry breakthrough, and it’s like, oh, you can do this. And there are multiple founding fathers in different countries, and there’s a kind of mania for space stuff. And it’s mostly amateur stuff: it’s like goofball cranks, like weird young men blowing themselves up in parking lots.

And then there’s this kind of hinge point, which is for a variety of reasons that we go through a little in the book. The Nazis put a lot of money into rockets, and in particular they happen to have this guy named Wernher von Braun. People could debate this, but I think he’s generally considered a sort of genius — at least at management, possibly also at engineering. A kind of Elon Musk figure, in that sense: he seems to be the guy who can get things across the finish line. He invents this technology that is called the V-2 rocket. It’s the basis for all initial rockets both in the US and the Soviet Union after the war. But it’s still kind of a sleepy technology. But then ICBMs, nuclear missiles come up, and it suddenly is quite serious to have rockets. But no satellites until 1957 with Sputnik. And then everybody knows the story of this crazy Space Race.

And there’s a great quote that I love about this. I think it was by Michel van Pelt, who’s a scientist, and he said something like prior to Apollo 8 — which if you remember, is the one where three guys went around the Moon and came back; not that they landed, that was Apollo 11 — prior to Apollo 8, every estimate of the future of space was an underestimate. Nobody had expected it would happen so fast. But after Apollo 8, everything was an overestimate.

So it’s after about like 1970, that would be 1968, I think, people start having the zany space fantasies. And the reason they could reasonably think that is the price to put stuff in space, the numbers we have now, say, if you take from 1957 to like 1970, the price drops by between 90% and 99%. It’s an insane super fast drop.

But the reason for that is it’s starting from a crazy high point, right? So very loosely speaking, it falls from something like $1 million a pound — or let’s say kilogramme; you know, it’s order of magnitude, so I can do that — let’s say it’s about $1 million a kilogramme down to about, we used to always say $10,000. But then it stops. And in fact it probably goes up a little bit after the Saturn V era with the Moon landings, and the Space Shuttle — which was supposed to make space access cheap, regular, and safe — did none of those things, and possibly was the most expensive ride to space for 40 years.

So if you want to see depressing space literature, go to the ’90s when all the dreams are just super dead, and everyone’s trying to figure out some other path and nothing is there. And then in the late ’90s and up through Obama, we get these programmes through NASA. And I really think this is the big change: in the past we’d done cost-plus contracts with these companies — meaning they deliver the rockets, and then we pay them more money, regardless of how much they cost to make them — which is, for obvious reasons, not the optimal way to do it. It’s a kind of way to de-risk a risky business, but not a great way to save money.

So there are these programmes looking for private suppliers, and into the fray steps this young billionaire — millionaire at the time — Elon Musk, who makes a huge bet on a company that is called SpaceX. And with a lot of luck — it almost goes off the rails — they manage to make a rocket that’s a clean sheet design. All rockets pretty much are based on old military designs, which creates problems. This is a streamlined, simplified design. It uses a lot of off-the-shelf parts that only became possible because modern electronics are so good that you could just send stuff. A lot of NASA stuff is made to order, and so they made this much cheaper rocket.

So that’s the first big cost drop: when the Falcon comes along. That’s Falcon 1. But then Falcon 9 really changes the game. I know we can all make fun of Elon Musk on this and that, without this play by him and his company, you don’t get the big change, I don’t think. So starting around 2015, the price starts dropping, especially when they add reusable rockets. If you don’t know your space economics, the big cost of launching a rocket to space is you destroy it afterwards. The fuel to get up is quite cheap by comparison. But because you destroy the machine, as with any transport system, if you destroyed the aeroplane or the bus when you got to your destination, the tickets would be expensive. So they are able to reuse part of the rocket.

And since then, between mass manufacturing — at least by rocket standards — and reusability, and just their streamlined design, costs have dropped precipitously, in a way that wasn’t true from 1970 to 2015. So all those dreams from the early ’70s are back — some of them directly, like they’re referencing the literature from the ’70s. And then clues, like stuff like Elon is saying — I should say Mr Musk, I’ve never met him — and also stuff like Jeff Bezos is saying about giant orbital space stations. But I think the hype is really down to the change in cost, and it’s real and there’s genuine hype.

My favourite example of this is SpaceX. I haven’t checked the number lately, but Starlink has some number of thousands of satellites, it’s like over 3,000 now. I think prior to them starting to launch Starlink satellites the total number ever was like 9,000. I don’t think it’ll be long before the majority of all satellites are Starlink satellites. Unless something changes. So it’s a real change. Anyone trying to deny that there’s a real revolution is just, I think it’s like borderline conspiracy theory stuff. It’s a real change.

Why space settlement (probably) won't make us rich

Zach Weinersmith: There are a couple ways people talk about this. One is space-based solar. The classic argument is that you put a solar panel in space, there are different estimates, but let’s say you get about 10 times more power per area. Then you beam that back. And by the way, it’s also always on; there’s no intermittency. The old joke, which I think goes back to the ’70s, is the problem with solar is that there’s a planet in the way.

So it superficially sounds plausible. I think that 10 times per area is valuable because you say that’s my constraint: I can’t spend more than 10 times per panel if this is going to be worthwhile. And then you start thinking, already you’re really far in the hole just because of launch costs. It’s still something like $2,000 a kilogramme, say. And I looked this up, I think a solar panel weighs like 20 kilogrammes. So you’re already pretty far in the hole just putting the thing in place. So you have to ask yourself, what’s the marginal cost of putting an extra panel up in New Mexico or the Sahara or the Outback or wherever, versus trying to put it in space somewhere?

But then you add a lot of realism. People have this idea that space is empty. It’s not. It’s quite empty compared to your backyard, but it is still crisscrossed with radiation and little bits of debris — little rocks and dust and things that are moving at high speed, often. So you’re going to have people who maintain this stuff, and it’s got to be extra tough.

But the other thing, and this is something that really does it for me: people think space is cold, and in a physics sense, that’s true. But actually, if you look at the International Space Station, a lot of what you’re looking at, if you get an overhead view, is radiators radiating away heat. Why? Because you can’t dump heat into the void. There’s nothing. My nine-year-old was asking about this, and the example I came up with was: if you’re a blacksmith, and you have a red-hot piece of iron and you want to cool it off, what do you want to put in? Would you rather put it in the cold winter air or lukewarm water? I think intuitively the water, because you just have that density of stuff to take away heat. You don’t have that in space. You can only use electromagnetic radiation. So if you have a solar panel always facing into the Sun, this is a thing you’re going to have to deal with. It’s just this ultra-complex system that you have to maintain.

And by the way, when you beam back power, you have to have a giant receiver. So you’re not even off the hook for taking up land area. It’s not as big as solar on Earth, but it’s still big. So my theory on space-based solar — because if anyone at home wants to do a back-of-the-envelope, you’ll very quickly see it’s a bad idea — is I think it’s a kind of zombie idea. It sort of made sense in the ’70s when photovoltaics, like the cost of the panel itself, was quite high. Now they’re extreme like, right, so, meaning you have to maximise per area. And it’s just not true anymore. So I think it’s just not good. Unfortunately, agency heads and VC people bring it up a lot. I just think, if you just run some numbers on a piece of paper, you won’t get even close.

Another one is asteroid resources. So maybe someday — and I would say sort of trivially, if you want to be like, 10,000 years in the future, where we’re all on a Dyson sphere, by all means — but if you’re talking about anytime soon, the first thing to know is that absolutely there’s valuable stuff in the asteroid belt. There is, it’s worth noting, a lot more valuable stuff just in the earth. If we’re allowed to say anything, Earth is very big. The question is what you can get at a profit.

And I guess what I want to say is that it’s just really hard to get stuff from the belt. So the belt is far away. It’s farther than Mars, which already takes six months to get to. You may have this idea from Star Wars that asteroids are kind of like big potatoes that you can just sort of grab, but actually they’re generally rubble piles, these loose agglomerations of dust and stone. People seem to have this idea that there are like hunks of platinum or gold floating around — and there are not. There are asteroids that are high in what’s called PGM, platinum-group metals — like rhodium, platinum obviously, I think iridium maybe — which are valuable. But they’re not made of this stuff; they’re just fairly high in it compared to Earth.

So if you look at the ideal asteroids — which are asteroids that are going to come near Earth and kind of lock velocity with us so that we can go get them more easily, and which are high in PGM — it’s on the order of like a dozen. There aren’t many. So you start to add up all the stuff you have to successfully do to just get one of these, and then maybe you want to try to refine it in space — which is really hard, because a lot of refining processes assume gravity — and you can see why there are all these dead startups that didn’t even get off the drawing board phase. It’s just a really, really hard problem, especially when you compare it to just digging a hole on Earth.

And then last thing, I’ll be quick about this. Sometimes people will say there’s going to be a translunar mining economy. All that stuff I just talked about is crazy; this is out-crazying all of that. The usual argument is you’ll get helium-3, which is an isotope of helium, which is valuable. But we estimated to get an OK amount, you’d have to strip mine miles of the lunar surface — which is, for reasons we get into, extraordinarily difficult. Michel van Pelt, who I think I quoted earlier, said something like, “If there were bars of gold on the surface of the Moon, it would not be worth it to collect them.”

The insight for me on that: if you think about Saturn V rockets, you’re talking about a skyscraper-sized rocket that goes to space, drops off like a dinghy on the Moon. Like, by the time they get to the Moon, it’s like a scrap of dust from this giant skyscraper. And in all those missions, they brought back half a tonne of rock, right? So what half-tonne material can you just pick up that’s going to repay the hundreds of billions of dollars? It’s just not plausible. So, sorry, I don’t buy it.

What happens to human bodies in space

Zach Weinersmith: One worth noting: just almost anywhere in space, the moment you step outside your suit or ship, you die. Nontrivial, right? And definitely in the places we are likely to go that is true, and that’s just the deal.

To give just a quick example of why space is a really fussy place to live. To me, this is a fascinating detail. Spacesuits are kept at lower pressure than spacecraft. And the reason is that it’s hard to operate, like a balloon inside, if it’s at full pressure. So we keep it at lower pressure. Just makes it easier to bend and operate the suit. In order to do that, you have to up the oxygen concentration so your lungs can still get enough. And we don’t like to do that in the craft because on both sides of the Cold War, there were tragedies related to pure-oxygen environments. Most American audiences know Apollo 1, but in the Soviet Union, there was a very similar incident with a trainee named Bondarenko. So it’s a real problem.

So the joke we have is, if you’re on your Mars hab and your friend is dying outside the facility, you literally can’t go save them. Because if you put on your suit without pre-breathing oxygen for a while, you’ll just get the bends, like a diver surfacing too soon. So you’ll just wriggle and die while your friend also dies. And actually, the only three guys who’ve ever died in space were Soviet cosmonauts — Patsayev, Dobrovolsky, and Volkov — who all died due to a valve opening when they were moving toward descent. So it’s not a little thing. Everything is going to be annoying, you know.

The next thing is radiation. Radiation is real bad. I won’t go into the details, but the short version is that in space, you get higher doses of different kinds of radiation than you get down here, and with unknown consequences. Radiation is poorly understood even on Earth; it’s even worse understood up there.

The data we have mostly comes from space stations, which are still in the Van Allen belts, so they get more radiation than we get down here. But it’s still different. We only have a tiny amount of data from the guys who got sent to the Moon, and they weren’t there for very long. It was on the order of weeks total. And it’s just, you know, we don’t know the effects of this stuff. And it’s scary. Probably the main practical effect is you’re going to have to bury your base under a lot of dirt. No glass domes for you. There’s a bunch more detail in the book if people want.

Then the big thing probably is microgravity. So in the International Space Station, you experience free fall, as if you’re in zero gravity. And reliably, that degrades bones. So we know bones — especially like hip bones; bones you don’t use a lot — lose something like 1% of density per month.

It’s crazy. And that’s with intense exercise, like six days a week on like a treadmill with a spring to pull you into it, and you still have this loss. Similar effects on muscles: they degrade over time. It’s considered very impressive if, when you come home, you can walk.

And there are other reasons for that, but one weird thing that happens in space is when you lose that gravity, you get a massive upward fluid shift. So you lose like 30% of the volume in your legs, and your face is sort of just poofy like a baby. They actually call it puffy face. It happens. The sinister side of it is it’s probably associated with this phenomenon where astronauts tend to come back with worse vision. And in fact, astronauts over 40 are sent up with what are called “space anticipation goggles,” assuming they’ll come back with it. This happens even on short trips. As I recall, it’s in our book, but I think it’s permanent, or at least semi-permanent. So it’s a problem.

And what’s most scary about this — you can always get glasses, I guess — but it’s possible that’s actually an early sign of broader nerve damage. So there’s equivocal evidence of cognitive negative effects on astronauts. We don’t have enough data. A big thing underpinning all this is that we don’t have anyone who’s gone longer than 437 days. I think the next person down is about a year. And it’s only like half a dozen people have gone that long. Most people are much shorter. So we really don’t have any kind of really long-term data. And by the way, a Mars mission is on the order of two to three years.

The ethics of space babies

Zach Weinersmith: You know, often when this comes up, it’s like, “Can you have sex? Can you have babies?” But in order to have a settlement, babies have to develop through all the stages of human development to be adults who can have children — and that’s where it gets really scary. So you describe all these medical things: imagine applying them to a kid whose bones are developing, whose vascular system is developing, whose brain is developing. We really have no idea.

And so the scary thing is, it’s not that we can’t get this data; it’s that without this data… You know, we have Elon Musk saying we’ll be there in 30 years. No one is collecting this data. There’s really haphazard experiments over time. There’s not much agency funding. As far as I can tell, there’s no funding from crazy billionaires. You know, we need this data. It’s going to be very painstaking to get — arguably unethical to get, because you at least have to experiment on primates before you’re willing to do it on human women. And it’s hard to imagine how you could even get good data unethically in a matter of decades. It should be a problem we’re pursuing now, if we’re really serious about space. Like, if tomorrow we found out Earth was going to be dead in 100 years, this would be part of the crash course, a big part of it.

What also worries is that if you do execute on this settlement, and you’ve got kids being born in these conditions, where you would expect a higher than normal rate of abnormality — you know, kids with cognitive deficits, physical deficits, who have trouble contributing to this hostile environment where they can’t get any care — on Earth, when you have special-needs children, some of us have complained about government services not being quite adequate, but there are at least services; there are ways to take care of these human beings. And that wouldn’t be true on any kind of medium-term Mars settlement.

And what’s scary is we found three different quotes from advocates in this community willing to say some version of, “We’ll just have to have natural selection do its thing” — which, you’re like, holy crap, this is like a horror science-fiction novel. They’re just saying the quiet part out loud, though. This is what would happen if tomorrow you snapped your fingers and there were a million people on Mars: you would be doing a mass experiment on babies, the result of which would probably be a large number of children who couldn’t be cared for.

So you know, I always say we’re concerned about space ethics. People are imagining we’re going to be like, “Do you really want capitalism on the Moon?” And there are people who want to bark up that tree, but we’re like, what we don’t want is vast experiments on babies for no reason — which seems to be a reasonable ethical posture for anyone, anywhere, ever.

Making babies in space

Luisa Rodriguez: You said we can probably have sex in space. Is the hard thing gravity?

Zach Weinersmith: Gravity. I’m debating how graphic to get here. It’s funny, one of the things we did for this book is we read a lot of old books forecasting the future of space. And there’s a sort of golden age of talking about sex in space, which is from somewhere like 1960 to 1980. I think it was just the right time. And it’s like Arthur C. Clarke, I don’t remember if we put this in the book, but he had some quote that was like, “Space is about to become more erotic.” And you’re like, oh god, Arthur. So yeah, space is Newtonian if you’re in microgravity; it’d be easier on the Moon. But basically that means if someone bumps into somebody else, they both go flying. So, again, from this period, there were attempts to figure out how to manage that.

We found two different proposals for what one guy called an “unchastity belt,” which is a sort of elastic waistband for two. And it’s funny; you hear that and you’re like, “OK.” And then you think, “But wait. Like, how, exactly?” And then you’re like, “Maybe I’m just not gonna…” Yeah. And then there’s another one called the “snuggle tunnel.” I forget who proposed that, but it was basically, imagine a large pipe with holes in it for ventilation, because CO2 tends to build up in your mouths if there’s not ventilation. And I could go on, but…

Luisa Rodriguez: I’d argue that space did not get more erotic.

Zach Weinersmith: No, it has not gotten more erotic. The dream of Clarke has died. I mean, worth noting that space notoriously kind of smells bad. And by the way, you change undies every something like four to seven days. So it’s just not… The mood lighting is not present. There’s not a lot of private space.

But when I say it probably could happen, basically I’m referring to anecdotal reports from men who said they were up for it. We found two men admitting to space onesomes. So that’s what I mean by that. Whether you could actually bring the baby to term, I mean, who knows? I say the human body is not designed for zero gravity. But you could note, and this is kind of goofy, but we looked up, does anyone do headstands while pregnant? And apparently this comes up in yoga, and it’s OK. And so apparently foetuses could do negative one gravity. I mean, they are kind of in a neutral buoyancy tank. So maybe it’s fine.

I’d be more worried about some sort of cellular-level process that depends on gravity in some way or another that we’re not thinking about. But, you know, it is the case that evolution would at least design it so a woman could trip and fall and the foetus would be OK. So clearly you can alter the sort of acceleration that’s being put on the foetus, to say it in a weird way. So that’s why I say it seems plausible that the baby might be able to come to term, unless something we don’t know is happening.

There are also little other off-ramps. The atmosphere in a space station is very different from what we get on Earth, so they tolerate a much higher level of CO2, because they have to. It’d be very expensive and mass-consuming to have a bunch of CO2 scrubbing going on. Ideally on a Mars base, you’d have a lush ecosystem to manage that, which is a tall order. And there’s other stuff. So imagine you get a package from Amazon: you open it and you often smell factory gases, and you don’t care because they go out the door. In the space station, they actually have to check stuff for outgassing because it can stay in the system. You have to be really careful about this stuff. So a plausible scenario is you might have, say, a high rate of spontaneous abortion for unknown reasons. I could go on, but there’s just a lot of stuff that we don’t know about.

A roadmap for settling space

Luisa Rodriguez: If you were in charge of Operation Settle Space, what would the roadmap that you’d advocate for look like?

Zach Weinersmith: Yeah, so our roadmap is how we close out the book. We say, you know, with all the naysaying we’re doing, if you put us two in charge of a NASA level of funding for an agency oriented around putting a permanent settlement on Mars, the three big tracks for us…

So one thing I will say: we’re making an assumption, which is that the rocket tech will continue improving. Because basically, I was sceptical of a bunch of economic stuff, but orbital stuff geosynchronous and below are extremely valuable for data transmission, remote sensing, navigation, all sorts of stuff: no doubt big money. So I’m just going to assume the rockets and spacecraft just keep getting better.

And so rather, what we focus on is: one is the reproductive question that we’ve already gone through in detail. But you’d want some kind of experiment that basically goes up the phylogenetic chart from simple organisms to humans. Again, that is still ethically questionable, but let’s just say you had to do it. That would be the way you’d want to do it.

Two, you would want to design these closed-loop ecosystems, and proof them out. That means building a lot of them, trying to find the minimum size and the optimal blend of species, and making sure they can last indefinitely. “Optimal blend” meaning it produces a lot of calories and clean water and air.

And then you would want to take those two tracks, ideally, and converge them on the Moon. So if you really wanted to prove we could do Mars, you would want to build a pocket somewhere on the Moon — maybe in the lava tubes, which are something we didn’t get into — where you would have one of these greenhouse systems that’s sealed, and where you have animal organisms. Maybe show that, you know, goats can have baby goats. And like I said, I’m still sort of ethically like, gosh, given that there’s no obvious short-term reason to do this, is it ever ethical to do this for human children? But we could set that aside. This is what you’d want to do if you had to.

And then the third track is that right now, we have a really bizarre legal international order in our approach towards space sovereignty. And that can be changed; this is all human culture stuff. And we know from the history of how the sea has been managed that the scribblings of a philosopher in one age become the law of the Earth in another.

So right now, and without getting into the details, we have a system that is kind of conflict-prone: it allows no sovereignty claims, no territorial claims, but does allow, depending on your interpretation, ad libitum claims of resources. And so, if you were setting up an agency to proof this out, you would want one oriented around governance — both to try to think about, and maybe even try to implement, an optimal international legal framework; and then perhaps even harder, determine the least bad way to govern a small initial outpost under these extraordinarily difficult conditions.