Progression of space industrialization

Part of my series on common misconceptions in space journalism.

Also, an update of sorts to my post on industrializing Mars.

Ever since SpaceX publicly announced their overarching mission to build a self-sustaining city on Mars, countless articles have been written about all sorts of related things. In many ways, this whole blog series is a reflection of this explosion of common media interest. Relatively few articles go so far as to dive into (literally) the nuts and bolts, and fewer still give any useful insights into the process.

Industrializing is really difficult. In August 2020 Starship SN5 has just hopped. It’s easier for a country to industrialize now than ever before, but even so – Mars is just a really terrible place to live. Living there, in any real sense, is utterly dependent on all kinds of advanced technology, and building it all locally is a very tall order. For more on the interactions between technology, environmental hostility, and population, check out my case study on Iceland.

What I will explore in this blog is how the Mars city will go about industrializing. Initially, a small population will make relatively few things, and later on a much larger population will support ongoing production of all kinds of stuff. What gets made first, and how much?

Let’s look at a representative sample of products consumed by the US on two axes: consumption rate per capita and price per kilogram. Consumption rate can function as a proxy of how much of a given thing is needed, while price is a good proxy for manufacturing difficulty, including labor and energy inputs. There are several big caveats here to explore in later paragraphs.


The result is the above graph. The inset lower left breaks out some of the densely clustered points in the middle.

The trend shows that, for the most part, we use more of cheap things, and less of expensive things. Or, for a given consumption rate, small things have a higher dollar value density. For example, morphine is waaay off to the left not because it costs a lot (the numerator) but because the usage rate is really low (the denominator).

How do we interpret this in the context of a future Mars city?

For the most part, cargo mass constraints will encourage local production of items in the lower right corner, gradually trending up and to the left. Over time, with more local manufacturing of mass-intensive products, a greater fraction of import cargo can be devoted to humans rather than bulk, low value commodities.

Of course, relative costs and usage rates would move quite a bit. All things being equal, I think the need to have most people working on factories inside entirely artificial environments means that, to a good first approximation, the per capita usage would be about ten times higher than on Earth.

Some high volume resources would vary on usage and cost. For example, water and various gases (particularly nitrogen) would be both harder to make and much more in demand than on Earth, moving their graph location up and to the right. On the graph, I’ve marked these products with an asterisk.

At any given time, there is a dollar import cost and desired level of self-sufficiency, giving rise to the red shaded region. In this graph, it’s set according to parameters given in a recent Mars city design competition, but its overall trend is down and to the left over time.

That is, there are two competing trends wherein increasing population enables greater specialization and cheaper labor, incentivizing local manufacturing of steadily more complex products (the diagonal axis shifts left). On the other axis, shipping costs are likely to trend downwards over time, incentivizing import of products with relatively high complexity compared to usage rates (the horizontal axis shifts downwards). This trend competes with local manufacturing cost reductions (in part dependent on shipping costs) for re-offshoring of any given production system. In practice, I think the trend will favor monotonically increasing autarky.

The blue zone at the top of the graph demarcates potential products in terms of volume of demand or cost that could be profitably exported from Mars back to Earth, given rather optimistic shipping costs. It is empty, because there are no known resources in space that could be sold profitably on Earth.

Everything in between is imported. In the given case, many drugs are used in such low volumes and are so difficult to produce that importing them makes sense. Similarly for mechanical devices such as actuators and bearings. Of all the parts of machines, these are both relatively light and relatively expensive. A local nexus of cost density.

In contrast, metals, gases, water, most food, plastics, and other bulk materials are made locally.

What this diagram does is provide a way to think logically about how an industrial stack can be built up over time, and the ways in which various components move up the value chain towards a finished product.



15 thoughts on “Progression of space industrialization

  1. Your series on creating an industrial stack on Mars is excellent, and a good antidote to other writings that do not think deeply about the problems and costs of settling another planet. I find writings about Mars/Lunar settlement that do not discuss concrete issues are either too glib or too pessimistic about the possibilities. It sounds like you have an entry in this years’s Mars Society competition – I’d love to see your full proposal. In particular I’d be interested to hear about governance and legal issues. Much writing on Mars settlement seems to assume a project directed unilaterally by one entity (SpaceX, NASA, etc), and there is almost no discussion about the current context of a developing new space race with China. Among most US writers I have seen there certainly is little grappling with the Outer Space Treaty’s tension between competing principles of “no national claims of sovereignty,” development and access of space resources for the “benefit of mankind”, and private profit. In what kind of legal/diplomatic context do you see a SpaceX-type industrial stack settlement being built? Or, to put it the other way around, how does the legal/diplomatic context affect the type of settlement that can be built? And by whom?

    I hope you keep posting, I learn a great deal from your thoughts.


    1. I’ll publish the entry after the competition is run.

      I don’t have very deep thoughts on governance. Some laissez-faire syncretic system with very distributed power is probably the way to best attend to the needs of the city, together with a system for rapidly iterating every aspect of governance to be responsive to evolving challenges.

      OST is interesting but I suspect easier to change/interpret in service of large scale human populations in space than the other way around.


  2. Interestingly, the one commodity that IS potentially exportable from space is the one that you have already identified, but didn’t list here: Information. Specifically, entertainment. On a planetary surface with only ~0.4 G acceleration, exotic extreme sports and competitive sports video might find a ready market. (Imagine the 30m platform diving event for the 2074 space olympics.) It would have near infinite cost/density value and be consumed in large quantity/capita. Thus, it may be the single most valuable export that Mars might someday offer.


  3. While there are no materials worth exporting to Earth, it may be worth exporting bulk materials to Earth orbit, e.g. water and steel, taking advantage or the lower escape velocity from Mars. Those empty cargo Starships may as well carry something back when sufficient steel is available to undercut their scrap value.
    I think they can be put to better use, e.g. for pilot asteroid mining projects on Phobos and Deimos.


  4. Shipping stuff from Mars to Earth should be cheaper than the other way ’round. You’re making propellant to reach orbit in the small gravity well, and aerobraking in the the thick atmosphere. And the Starship itself is worth its scrap value on Mars instead of its production cost on Earth.


      1. Marginal cost is what matters. If propellant is cheap enough on Mars to make it cheaper to reuse Starships than scrap them, the cost of getting one more Starship load of stuff to Mars is the propellant for the round trip, plus the use of a Starship for the whole time, plus any operating costs. For a load back to Earth, there are empty Starships coming back, so the cost is just the difference in propellant required for the extra mass.


      2. I agree with this in principle but my feeling is current SpaceX design thought is that it’s easier to make a new starship on Earth than to fly one back from Mars. If true, that means Starships are wonderfully cheap.

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      3. As we’ve said many times, what’s clearly worth sending back to Earth is information. That means actual data in photons, but it also means samples, both of rocks and of equipment. If engineers on Earth have a bunch of tele-robotic equipment that has been used on Mars, a few Starships that have flown to Mars, and a lot of pieces from Starships that have been scrapped on Mars, they can examine it all and see how the wear and damage differ from what they expected.

        Scrapping a few Starships is also a source of information about how various processes work on Mars. With the materials they contain, the Martians will be able to run a lot of projects at pilot scale before they have the ability to make all the inputs locally. Industrial development will proceed according to what makes sense for the people, rather than being constrained to go in the order that the processes would dictate.


      4. Marginal cost certainly matters, but so does the resale value of whatever it is you’re exporting. Let’s say that I have a bunch of Martian steel, and I’m thinking about exporting it to Earth. The future versions of the Starship run on nothing but the strength of Elon Musk’s vision, so the marginal cost of exporting the steel is $0. On Mars, steel has low supply and high demand, so I can sell it locally for $1000. On Earth, steel has high supply and (relatively) low demand, so the price on Earth would only be $100. Even with no marginal cost, exporting the steel still doesn’t make sense.

        The only items I can think of where supply is higher and demand is lower on Mars than on Earth are used Starships and homesick colonists. Even though conventional exports may not make any sense, passenger transit may be more viable than we usually assume.


  5. –current SpaceX design thought is that it’s easier to make a new starship on Earth than to fly one back from Mars. If true, that means Starships are wonderfully cheap.

    Maybe just fly the occasional starship back to Earth with a cargo load of all the unneeded (or Mars) high value Raptor engines? The rest of the starship could stay on mars for reuse/scrap?


  6. How about export from Mars to some place other then earth? I don’t know about the delta-v required but is it cheaper to export from Mars or the Earth if you’re going to Earth’s moon? Or even LEO?


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