Dr. Metzger's model of economics of starting a city on Mars

[su27k]

https://twitter.com/DrPhiltill/status/1608697765294669825

Akhil linked a very interesting paper. In it he argued that the economics of shipping goods between planets dictates that neither the minimum energy trajectory (Hohman transfer) nor the minimum time trajectory is optimum, but something in-between.


Related: when building a civilization on Mars, it is wrong to think that we should ship goods to/from to Mars only when the planets are aligned once every two years. That trajectory is the optimum to a *different* economic problem than starting a city on Mars. 2/n


When a space agency like NASA can afford only one mission every two years, then obviously they’re going to send it on a trajectory that allows maximum payload mass. So they need the planets to line up. But if you’re building a city on Mars… 3/n


…then the extremely high finance cost drives you to get the city profitable ASAP, so you *must* launch missions from Earth as fast as you can, launching every day all year long to get as much manufacturing hardware and workers on Mars as fast as possible. 4/n


A huge chunk of the year when the planets aren’t aligned costs only modestly more in propellant than waiting for optimal alignment of planets. Like maybe 10% more iir for many months. So is it worth holding back crucial hardware from Mars to save only 10%? 5/n


I haven’t run the numbers but I suspect that the gigantic leveraging of finance costs and the delay of reaching sustainability will drive departures to Mars all year long. Many clustered around the optimum alignment of planets, to be sure, but many others not. 6/


A problem I run into sometimes in the space community is that we operate from a set of heuristics like “we only depart to Mars when the planets are aligned” without realizing those heuristics were developed in a different economic paradigm so they aren’t generally true. 7/7

[TrevorMonty]

Humans will need shortest trip to Mars to reduce health effects of zero G and radiation exposer. Also longer trip more suppliers are needed.

[JohnFornaro]

A problem I run into sometimes in the space community is that we operate from a set of heuristics like “we only depart to Mars when the planets are aligned” without realizing those heuristics were developed in a different economic paradigm so they aren’t generally true.

I'm afraid the "economic paradigm" here exists only in Metzger's head.  His point about the time value of money is valid.  Building a city faster means you can profit sooner,  but sadly,  the transportation problem and the infrastructure problem have not made it to cis-lunar space yet.   Remember, SLS only ran a circle around the Moon just the other day.

Edit 02-16-23:  The paper Metzger links to does not seem to exsit?

https://twitter.com/ThatAkhilRao/status/1608563529438875649

[Twark_Main]

he argued that the economics of shipping goods between planets dictates that neither the minimum energy trajectory (Hohman transfer) nor the minimum time trajectory is optimum, but something in-between.

Isn't this intuitively obvious?

Some costs are per-unit-time (eg radiation and consumables), and some costs are per-unit-propellant. So obviously the cost-optimal route is somewhere in the middle.


Same for shipping. We can observe that it isn't run at the fuel-optimal speed (very slow, generally) or the time-optimal speed (eg full throttle across the entire Pacific). It's a compromised trade-off between the two.


You can of course sometimes find situations where the optimum is "pegged" at either end of the dial (eg terrestrial trucking always riding the speed limit), but that only means that technology limitations are preventing you from reaching the true optimum.

[Slarty1080]

he argued that the economics of shipping goods between planets dictates that neither the minimum energy trajectory (Hohman transfer) nor the minimum time trajectory is optimum, but something in-between.

Isn't this intuitively obvious?

Some costs are per-unit-time (eg radiation and consumables), and some costs are per-unit-propellant. So obviously the cost-optimal route is somewhere in the middle.

Same for shipping. We can observe that it isn't run at the fuel-optimal speed (very slow, generally) or the time-optimal speed (eg full throttle across the entire Pacific). It's a compromised trade-off between the two.


You can of course sometimes find situations where the optimum is "pegged" at either end of the dial (eg terrestrial trucking always riding the speed limit), but that only means that technology limitations are preventing you from reaching the true optimum.

Yes it entirely depends on what the goods being shipped are

[Alexsander]

My guess: cities will appear naturally on Mars.

Considering Starship and 100 T to Mars surface, we'll have:

- First, robotic missions will build a few small bases with adapted containers ("trailer park" research stations), at "rover distance" from each other. Some stations will be state-owned, others will be private.
- Each 20 ft container would be a self contained pressurized habitat; several types, like dorms, labs, kitchens, greenhouses, etc. They would have a standard hatch/airlock allowing the robots to connect them in a large pressurized area.
- Robotic ISRU will make air and water; FSD trucks could travel back and forth between the "trailer park" and the "mines", storing the resulting liquid and gasses in tanks near the containers.
- Crewed missions will occupy the research stations, Antarctica style. Humans will bring seeds for farming, livestock and lots of packaged food. They will connect the ISRU tanks, etc. The first crews will be mostly scientists.
- After the first bases are up and running, the tourists will follow.

[Twark_Main]

20 ft container would be .. pressurized

There's a reason why most pressure vessels don't have flat sides.

A standard shipping container can't even be buried underground (the walls will collapse), and that's less than 1 atmosphere of differential pressure.

Early habs will almost certainly be cylindrical, not prismatic.

[Alexsander]

20 ft container would be .. pressurized

There's a reason why most pressure vessels don't have flat sides.

A standard shipping container can't even be buried underground (the walls will collapse), and that's less than 1 atmosphere of differential pressure.

Early habs will almost certainly be cylindrical, not prismatic.

You mean like this? I think the "container" format has some advantages: easier manufacture and transport on Earth (more competing suppliers = lower price), easier to stack inside a Starship, easier to unload with a "pez dispenser crane", etc. The cubesat standard shows that a standard format helps.

[Twark_Main]

You mean like this?

Yes, that's exactly what I was picturing actually!

Obviously the size (and stackability) won't be suitable or needed for all purposes. Ultimately I expect stick-built buildings similar to skyscrapers, except the 3D grid of structural beams is mostly holding back internal pressure tension.

[Proponent]

In the model services are broken out specifically as things not requiring transport of material. Tourism not a part of it.

Selling pet rocks on Earth has been proposed before. To make that work you need a cult like NFTs, MLM, Trump merch etc.

A lot of other stuff is probably killed by the 10-40 min latency in communications, especially as Earth stuff is increasingly habituated to more automation.

So, as I said, I don't understand how it could work. If the author understands, that is not clear to me.

I struggle to understand this too.  To re-frame the problem, why not build a similar economic model for a city, in descending order of "cool factor":

    * On the moon;
    * On the ocean floor; or
    * In Antarctica.

I suspect that, for little reason aside from the lesser cool factor, people will tend to view a city in one of these locations with much more economic and technological skepticism.

[su27k]

I struggle to understand this too.  To re-frame the problem, why not build a similar economic model for a city, in descending order of "cool factor":

    * On the moon;
    * On the ocean floor; or
    * In Antarctica.

I suspect that, for little reason aside from the lesser cool factor, people will tend to view a city in one of these locations with much more economic and technological skepticism.

Because someone who is worth more than $100B have committed to fund a City on Mars? Nobody has made similar commitment to fund City on the Moon etc, if someone comes out and make such a commitment I'm sure somebody will build the corresponding model.

BTW as Robotbeat puts it, Dr. Metzger is mainly a Moon guy, his main interest in economic modeling is industrialization of the Moon, Mars is just his hobby.

[Twark_Main]

Services? YouTubers on Mars, of course. 



I think it's fundamentally hard to take a top down approach, where your reasoning stems from "it's just like the Earth economy, but tweak X."

I think the bottom-up approach is the only feasible option. You have to individually cost the solutions for different physical needs, then economically balance them. IOW, you have to actually solve the problems. Imagine that...   

[Paul451]

I think it's fundamentally hard to take a top down approach, where your reasoning stems from "it's just like the Earth economy, but tweak X."
I think the bottom-up approach is the only feasible option. You have to individually cost the solutions for different physical needs, then economically balance them. IOW, you have to actually solve the problems.

At the very least, cost enough individual components under Mars assumptions that you can then compare them with Earth costs to develop a "conversion factor" when grabbing whole-of-economy numbers that Metzger used.

[You can also then test your assumptions by comparing with commodity-cost vs transport-cost of isolated communities on Earth and seeing if the US is a suitable starting point for this exercise.]

[Twark_Main]

I think it's fundamentally hard to take a top down approach, where your reasoning stems from "it's just like the Earth economy, but tweak X."
I think the bottom-up approach is the only feasible option. You have to individually cost the solutions for different physical needs, then economically balance them. IOW, you have to actually solve the problems.

At the very least, cost enough individual components under Mars assumptions that you can then compare them with Earth costs to develop a "conversion factor" when grabbing whole-of-economy numbers that Metzger used.

Even then I'm not sure.

If you break it down as a constant cost multiplier for all goods and services, it's probably hopeless.

I think you'll have to separate out labor cost vs real-estate cost (pressurized and unpressurized) vs material cost (per material) vs energy cost. Each of these will have a very different cost multiplier, with human labor probably being the worst.

[high road]

To add to the difficulty: the cost multiplier for a single activity becomes much larger as you scale up, but it eventually becomes smaller again when local industries start to support each other.

The largest part of the human labor cost would be that they need to be able to pay for the other three to survive and be happy. Compared to that, any retirement-on-Earth-savings-plan would be infinitessimal.

So IMO you can safely express 'labor cost' in 'import costs for one FTE'. While real estate cost, energy cost and material cost would be a combination of labor cost and imported mass cost. It's a continuing excercise where you assume some numbers to refine others, then do the reverse to adjust the numbers you assumed.

[JulesVerneATV]

the Moon as a stepping stone to Mars

NASA STI program

https://web.archive.org/web/20241118084338/https://www.nasa.gov/wp-content/uploads/2024/01/rev-a-acr23-esdmd-001-m2madd.pdf

[Slarty1080]

The Moon may help as a stepping stone to Mars with advancement of a number of technologies, but in the grand scheme of things this will be more useful than decisive. The economics of starting a city on Mars are something else entirely.

As I see it, the cost of getting things to Mars needs to be reduced by 1-2 orders of magnitude or more otherwise the whole thing is impractical. Hopefully Starship will eventually achieve that (it remains to be seen but I'm hopeful). However even with Starship a vast amount of money will still be required for all manner of development work and in situ testing.

There are a number of financial funding possibilities such as Congress for national prestige, jobs, science etc. Then potentially philanthropic billionaires like Elon Musk and others might fund some aspects. Then there is tourism, science, spin-offs, advertising and tv rights etc.

But not all of these are entirely reliable, Congressional priorities change, billionaires eventually die and the likes of tv and advertising are fickle. So it will be absolutely vital to ratchet up self sufficiency as quickly as possible to ensure costs are kept down. Whether costs can be reduced enough quickly enough to allow a truly permeant human presence on Mars is IMO an open question.   

[BN]

many people are willing and ready to move to mars to help build the next stage of human civilization. this includes fairly wealthy people who will fund their own presence there and make investments there.

most are underestimating the sheer life force and resources waiting to be thrown at mars for reasons beyond short term monetary gain.


dying on earth is old hat.

[Phil Stooke]

I will be encouraging all the billionaires of my acquaintance to make the trip.