After sitting on my shelf for over a year, I finally had a chance to read through Zack and Kelly Weinersmith’s book on space settlement, A City on Mars, and I wanted to share a few of my thoughts. I know that their book wasn’t particularly popular in the space settlement community, but I’ve been a fan of Zack’s SMBC webcomic1, as well as his graphic non-fiction book on immigration that he wrote with Bryan Caplan (“Open Borders“), as well as his delightfully silly graphic novel “Bea Wolf“2, so that predisposed me to try to give them a fair shake, even though I knew I likely wouldn’t agree with their conclusions.
tl;dr, I enjoyed the book, and am glad they wrote it, even though I strongly disagree with at least some of their conclusions.
This won’t be a long review, but I wanted to share a few random thoughts I had while reading the book:
- I liked the intro they gave to some of the physiological unknowns we face with space settlement. Those who’ve followed this blog know that I’ve been beating on the drum of the importance of getting real hypogravity health data for almost two decades now3. I’m in strong agreement with them, that for those of us who care about space settlement, that getting to a point where we can start gathering hypogravity data ASAP is critical. JAXA is finally doing some initial forays into this, but we need to do a ton more. My company, Gravitics, hopes to be working in this area at some point in the future, but it’s definitely an area that needs more attention.
- As a die-hard Venus cloud colony advocate, I was sad that the idea only got a one or two paragraph side mention. Zack obviously hasn’t read the Venusian Acid-Cooked Turkeys post from a few years back.
- I somewhat agree with them that a lot of the utopian rationales for space settlement are overhyped, though I think they take their criticisms too far. For instance, yeah I don’t think space resources are going to displace all mining and industry on Earth overnight, or single-handedly solve environmental problems. But I do think that they can contribute around the edges in ways that are meaningful and worthwhile. They can displace some mining and some industry, they can contribute to the overall solutions of climate problems. Something doesn’t have to be a panacea to be worth doing.
- I agreed with them that Helium-3 mining on the Moon is unlikely to be financially worthwhile. I’m friends with the CEO of a company (Helion Energy) that is working on developing a D-He3 fusion generation system, and if things go well, will be trying to demonstrate electrical breakeven with their most recent prototype later this year. But are they planning on going to the Moon to get the He3 they need? Nope, they’re planning to breed it in D-D generators, and likely could do that for far cheaper than getting He3 from lunar regolith. My friend points out that there might be places in the solar system where you could mine He3 at a price point that could be competitive with having D-D breeders create them, but so far, that’s most likely going to be gas giants like Neptune or Uranus, not the Moon4.
- That said, I do think they undersell the potential of their being economically exploitable resources on the Moon, or about all of the value being tied up in just two tiny regions near the north or south pole. The moon is huge, and we’ve only scratched the surface of it (literally). By definition, most mining takes place in locations that have atypical concentrations of resources, not average places. While the Moon doesn’t have the same resource concentrating mechanisms that the Earth does, that doesn’t mean they don’t exist. Dennis Wingo, for instance has made a pretty good case for the potential for some near-surface, low-impact-velocity PGM asteroids on the lunar surface. I think once we are able to visit the Moon regularly, and especially once we have people living there and working their permanently, we’re going to find that it’s as varied, weird, and interesting of a place as Earth is.
- I also was strongly unconvinced about their fears about the existential risks posed by space settlement. While I wholeheartedly agree with them that human nature will almost certainly follow us into space, and that wars in and because of space are likely inevitable, I’m not as worried as they are, and I don’t think they did a particularly good job of explaining why people should take their worries seriously, especially their worry about space settlement leading to people flinging space rocks at Earth. They referenced work several times by Daniel Deudney on this topic, but never gave enough details in this book to know how seriously to take this argument. Personally, based on my experience with the planetary defense community, I’m extremely skeptical about this risk. Most papers on asteroid deflection could be summarized as “If we have at least 10-20yrs of advanced notice, and are willing to throw a ton of the resources of an 8 billion person planet at deflecting a potentially civilization ending asteroid, we might just be able to nudge its path by ~1 Earth radii so it will fly by without hitting us.” Basically, moving rocks big enough to be an existential threat is not trivial, whether you want to move the to avoid a catastrophe or cause one. Frankly, I could write a whole blog post on this, because I think this is their single biggest reason for being afraid of space settlement, and I find the argument extraordinarily unconvincing. I haven’t had a chance (or honestly the desire) to read Deudney’s work, so maybe he makes a more compelling case, but color me unconvinced. I should say though that is does point out the value, as humanity starts spreading throughout the solar system, of setting up systems to track natural and man-made objects to keep an eye out on things.
- As a pragmatic libertarian, I was also extremely unsold on the desirability of tying up extra-terrestrial resources in some sort of Moon Treaty like bureaucratic mess. I think something that’s become more apparent in the last year or two that bureaucratic stagnation carries its own geopolitical risks. Just look at populist parties throughout the western world capitalizing on discontent over sclerotic bureaucracies as a way to gain power. Given how much traction the Artemis Accords have gained since their writing, I’d also be interested in getting their take on them, as their discussion of space law, barely touched on them in passing.
- I do agree with them though that we have a lot of learning to do before we’ll be ready to settle space, and we’ve made depressingly little progress on burning down those risks over the past two decades that I’ve been involved in space. I don’t think we should wait till we know everything, but we definitely should be doing a ton more to burn down those risks.
- I do agree with them that it’s going to take a lot of people off-world to make space settlement a true Plan B for civilization. But I also think though that there are huge confounding factors with using North Korea and Cuba as their basis for estimating how many people you would need for off-planet civilization to survive the loss of Earth. Unless we really screw up, I think we’ll get a diverse set of off-world settlements and activity, and those will almost certainly be trading with each other. Working to make your civilization resilient to supply-chain disruption isn’t the same thing as trying to be a hermit kingdom. It’s more akin to the concept of friend-shoring than it is to autarchy and isolationism.
I could go on, but those were some of my main thoughts. Once again, I’m glad they wrote it, and I enjoyed reading the book, and even agreed with some of the conclusions, but definitely don’t share their overall conclusions.
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Jonathan Goff
Director of Advanced Concepts at Gravitics, Inc.
Jonathan Goff is a space technologist, inventor, and serial space entrepreneur who created the Selenian Boondocks blog. Jon was a co-founder of Masten Space Systems, and the founder and CEO of Altius Space Machines, a space robotics startup that he sold to Voyager Space in 2019. Jonathan is currently the Director of Advanced Concepts for the space station startup Gravitics. His family includes his wife, Tiffany, and five boys: Jarom (deceased), Jonathan, James, Peter, and Andrew.
Jon has a BS in Manufacturing Engineering (1999) and an MS in Mechanical Engineering (2007) from Brigham Young University, and served an LDS proselytizing mission in Olongapo, Philippines from 2000-2002.
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- Though I’m probably one of the most prudish people who can say he likes their comics. Some of them are definitely Not Safe for Jon (NSFJ) however.
- I read this one out loud to my boys, and think that ironically many of the people who didn’t like A City on Mars, might actually be the people most likely to get a laugh out of Bea Wolf.
- See here, here, and here (this one by coblogger Chris Stelter) for some examples.
- Gas-phase ISRU is just so much easier than solid-state ISRU, especially when you’re talking about diffuse resources.
I am of the opinion that planetary defense against Large Unfriendly Rocks (LURs) will be somewhat simpler than most papers suggest, IF done properly. Somewhat like low gravity research it will just take one group with vision and resources. Somewhat as SpaceX is doing with LEO transport.
John,
I think so too, my only point is that defending from a natural LUR is probably orders of magnitude easier than deliberately maneuvering a LUR into an Earth-intercept orbit.
~Jon
I have to agree that human health in hypogravity environments is a big question mark. The only way to get definitive data is to have a large enough cohort of people on the moon for a long enough amount of time to get measurable data. It may also be necessary to perform experiments to see how linear the effects are as well. The research would also have to extend into reproduction if the goal is some sort of permanent colony.
Mining in space isn’t covered that well in fiction and I haven’t seen research into it with companies concentrating on vehicles more than the machinery needed once in space. Given how much materials on Earth go through a “once-around” use before being discarded, there could be more money spent there before even studying what it would take to replace those materials through breaking down an asteroid and sending ingots back to Earth.
“Zack obviously hasn’t read the Venusian Acid-Cooked Turkeys post from a few years back.”
With some limp-wrist adjustments, it seems one could do some sunbathing in Venus atmosphere, but it seems one could tend to want to block about 1/2 of UV radiation. Venus at 1/2 of an Earth’s air pressure, +50 km elevation is quite cool, and where you are going be on Venus, could have no sunlight, or less sunlight than Earth. It seems on planets other than Earth, in our solar system, polar regions would be preferred.
If we weren’t in an Icehouse global climate, on Earth, they might be more attractive places to live.
If living on Venus, one will be mining the acid. And within a few decades, one might reach Peak Acid- have a shortage of it. Venus Acid is the liquid of Venus, liquid in terms of pure Acid, and water [and sulfur, which melts at a mere 239 F]. But even strong Venus acid, has a lot of water in it. But you might want to mine weaker Venus acid where it’s most abundant, to extract the higher concentration of the water.
And rather than export it, off world, one might want to use it on Venus.
At the hot surface, it’s too hot for the acid to exist, but with enough pressure, liquid water can exist. One might have vertical pipelines which are about 50 km tall.
Start with 9 meter diameter pipe [the balloon tank of Starship] and 1000 meter tall, and it can float in the lower denser Venus atmosphere [with lighter gas than CO2, in it] and float vertically, with having more mass at the bottom of it. And by controlling it’s buoyancy, it can be lower to hot rocky surface. Stack 50 of them and get the 50 km tall vertical pipeline.
Pipe water to bottom, get a steam engine.
Pipe sulfur to bottom and have liquid sulfur.
Pipe pure acid to bottom, and get pure acid, to that hot surface, which lacks acid.
Say, had 1000 meters of water at bottom of 50 km pipe. So the bottom has about 100 atm from the weight of water which is greater pressure than Venus surface pressure. And if surface pressure is, say 90 atm, the greater pressure is about 150 psig.
If was 900 meter column of water, instead, it’s is same- but 500 meters up, the atmosphere would have a greater pressure. But by having compartments in pipe one can add “air pressure” to be more the Venus atmospheric pressure.
Anyhow, one can have non boiling water at the Venus surface [very hot water but at high pressure]. And roughly it could similar to doing things in the deep ocean of Earth.
Anyhow, what I think is important about Venus, is Venus orbit, particularly high Venus orbit. Venus as hub of solar system- near to Earth, and Mars settlements or just early Mars exploration efforts will want to use Venus orbit.
We are going to get gas stations in Earth orbit, pretty soon, and we will then get gas station elsewhere. And if there is gas stations at Mars, our Moon, and/or Venus orbit and they all could be useful, but it seems gas stations at Venus orbit would be more useful.
Venus has more launch windows, and shorter distances and less time to anywhere.
It seems a new American rocket company could be based on buying Raptor 2 rocket engines. So it will offer to buy 100 Raptor 2 rocket engines from SpaceX. So 100 new Raptors for 1 million dollar each or 100 million dollars in total. And/or hundreds of used Raptor 2 engines for less than 1 million dollars each. Used would Raptor 2 engines fired a lot on engine test stands or engines which have launched into Space, that one would paid 1/2 million dollars [or less] for.
So, why would SpaceX do this?
First, SpaceX is making Raptor 3 engines. Second, you are going to build a larger diameter rocket. Third it’s going launch and recover rockets from the ocean.
So instead of a 9 meter diameter Starship you make a 12 meter diameter Starship- something, SpaceX is unlikely to do within the next couple of years. But it might be something that Elon/SpaceX might want to “try out”- and the faster the better.
Anyhow, the start up, would be based “or realized” upon getting the contract of new and/or used Raptor 2 engine from SpaceX. And investment capital would be related to cost building ocean launch site and making a 12 meter diameter first stage rocket, which would be tested on the ocean launch site. Once you launched and recovered the first stage rocket from the ocean, one could focus on the second stage. But you launch the first stage with an empty second stage- it does not have rocket engines and remains attached to first stage. One call that second stage a huge payload fairing, and part of business model is to launch larger than 9 meter diameter [12 meter] payloads to orbit.
And this version of “Starship” uses titanium rather than stainless steel- 4 mm thick walls which is stronger and lighter than stainless steel. It would have larger cross section, be less mass and be taller [when keeping the second stage when testing the first stage with the “second stage” attached].
I’ve been thinking for quite a while that a hypothetical moderate sized Kuiper Belt planet, maybe the mass of Mars, could be a great place to mine He-3. It would have to be far enough out that the temperature at the exobase of its atmosphere was low enough to retain primordial helium. Maybe at 100 AU? Getting out there and back in reasonable time would be predicated on fusion propulsion, but that presumably could come along with the technology package.
I want to add that recent developments have opened a new plausible justification for space activities, although maybe not on Mars itself. That is the AI boom.
While AI would be useful if robots could do things in space using it, it’s also useful as a justification for very large space activities. This is because AI could lead to very large increases in demand for power, even beyond what Earth could sustain simply from considerations of direct thermal pollution.
Consider what power draw could be justified by AI. If a person costs $100K/year, and power is $0.02/kWh (which I think is reasonable for solar in a decade if not sooner), then replacing a single person would justify up to half a megawatt of power (this ignores capital cost of course). In comparison, per capita primary energy consumption in the US is currently somewhere around 10 kW.
The potentially very large power draw that AI could justify is already prompting firms to look at where they could get this power, but at large enough scale Earth just can’t handle too much power-hungry AI. The place to put the servers beyond that will be in space, where the waste heat can be radiated and solar is available 24/7. Unlike old SSPS ideas, no power beaming would be needed.
We have a large fusion reactor, we call the Sun, and it could provide all the energy a spacefaring civilization could need- unless that spacefaring civilization wants to explore our galaxy and needs to travel somewhere close to the speed of light to do so.
It seems to me, our solar system, isn’t a good place to travel at such high velocities- we don’t have the star and/or the planets for that purpose.
Of course we can do some exploration of our galaxy and universe with very large telescopes, and we might start doing that soon, a few decades and/or once we actually become a spacefaring civilization.
Though once we see, what we are missing {not having a starfaring solar system} we might yearn for it.
It seems we might alter Jupiter in order to make Sol a better place to use for star travel and Jupiter has a lot He-3 to be removed {and H2 to be removed}. But that would only amount to a very modest improvement, what this place really needs are blackholes/neutron stars- and/or plus a few super Jupiters/very super Earths.
It seems to me, one of the 53 Artemis countries should partner with VIPER rover- which are suppose to be just US companies, but if a country can manage the paperwork of US govt, it seems it could be possible. It seem like a cheap way for country with not much of a space budget, to be 5th [or whatever] country to land on the Moon. So if interested in Space, it might be a faster way to get more interested in Space.
I’ve been a Helium-3 scoffer for years, but I recently got introduced to the wonderful world of dilution refrigerators. We don’t know whose quantum computing architecture is going to prevail, but if one of the attributes of the winner is that it needs milli-kelvin temperatures, dil fridges are going to jack the demand for He3 into lunar-distance orbit.
I suspect that the odds of this happening are slightly higher than the odds of D-He3 fusion becoming all the rage, but still pretty low. On the other hand, the demand upside is huge.
TRM,
Interestingly, once of the monetization ideas Helion had for their first generation D-D generators was basically that — selling some of the He-3 generated to people for use in that type of refrigeration system for quantum computing.
Paul D,
It’s interesting that a lot of the funding flowing into fusion startups right now seems to be focused on at least initially providing power for AI data servers. I think we’re a ways out from the point where it makes more sense to do massive datacenters in space rather than on the ground, but I guess it’s plausible, assuming current trends continue (which is always a risky proposition). It’ll be interesting to see how it all pans out.
Ken,
Sorry for the slow response, but yeah I agree we need a lot of data on hypogravity. I think some of it are things we can learn quickly — human health degeneration in microgravity is relatively quick, and pretty much universal. So even a moderate amount of time at various intermediate gravities should give preliminary data on if there is a knee in the curve where the worst of the effects seem to go away. I’d rather do that using spin gravity (I’m biased). Do the quick studies to get the lay of the land, then dig deeper at gravity levels of interest. As Joe Carrol has pointed out, there’s a few common gravity threshold in the Solar System, and finding out which of them are good enough (with or without countermeasures) for health effects is pretty important information to get. Agreed that getting info on things like long-term effects, reproduction, etc. will obvious take a lot longer. But how much changes in how we approach the Moon, and Mars if we say knew that someone living in lunar gravity for 10yrs wouldn’t suffer permanent damage?
~Jon