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The Economic Viability of Mars Colonization (1998) (aleph.se)
64 points by beerlord 3 days ago | hide | past | web | favorite | 36 comments





What an incredible detailed read covering many aspects of what potentialy will be mankinds greatest endeavour. And if, it can potentialy be happening in the mid-near future! Reading this really gets your sci-fi mind going. Thanks for sharing!

This paper calls Mars uniquely suitable, but only briefly references O'Neill on free-space habitats built out of lunar or asteroid material. His main argument against seems to be the need to protect from radiation, but it's not like O'Neill and successors did not know -- they had designs for that. Yes, a habitat with gravity and shielding and agriculture would be expensive. So would colonizing Mars.

> Assuming complete coverage of the planet with photosynthetic plants, it would take about a millennia to put the 120 mbar of oxygen in Mars' atmosphere needed to support human respiration in the open...Assuming the whole planet is covered with machines converting sunlight to electricity at 30% efficiency, and all this energy is applied to releasing oxygen from metallic oxides...atmosphere could be created in about 30 years.

Are plants really that inefficient? They're basically solar-powered nanomachines that release oxygen from carbon. Wikipedia reports "an overall photosynthetic efficiency of 3 to 6% of total solar radiation".


It's kind of an unsatisfying argument, but what I've heard (back in high school biology) is that the reason you see the relatively low efficiency is because that's all the plants need. In the course of evolution there was either not a great enough reward for more efficient photosynthesis, or no mechanism developed that was able to utilize something like 30% of incoming sunlight.

It's also important to remember that plants evolved to reproduce and spread as effectively as possible, not to be as photosynthetically efficient as possible. Engineered machines, however, can be designed with energy efficiency as the main goal.


Note that converting sunlight to electricity (what the 30% figure is about) is also quite different from using sunlight to convert CO2 to glucose (what the 6% figure is about).

Apparently the first stage of photosynthesis effectively does convert sunlight to electricity and does that with 90% efficiency, which is far beyond what our technology can achieve.

Source: https://www.economist.com/the-economist-explains/2014/12/03/...


It's also important to consider that photosynthesis only captures photons in a very narrow spectrum relative to the total spectral output of the sun.

But not all of the plant's absorbed energy goes into releasing oxygen.

In the end it depends on the economic incentives, or lack of them.

The potential economic value for space exploration comes from satellites orbiting earth (communication, sensors), mining near earth asteroids for rare and expensive minerals and possibly even energy generations. Moon is possible destination because it could serve Earth.

From the point of financing the effort Mars is just a sink. First spend hundreds of billions to start it, then billions per year to maintain it.

People don't spend their wealth to permanently reduce their living standards and the change for survival of their children. Permanently breathing bottled air inside a housing in a desert planet, having reduced lifespan etc. is not fun. All the space exploration romantics goes away in few years and people lose the interest.

If you want to colonize Mars permanently, first create (de facto) post scarcity economy on the Earth. Before that' there is no change for permanent colonization. Research settlement in Mars is possible.


> The potential economic value for space exploration comes from ... mining near earth asteroids for rare and expensive minerals

As the article describes, mining asteroids for rare and expensive minerals is more viable from Mars.

Earth is in an incredibly deep gravity well: it's remarkable that we made it out with just chemical rockets, an Earth just 1.5x larger in diameter would need a stack of something like 20 Saturn Vs to get one ton to LEO, instead of the 120 tons that a single rocket could do on Earth.

Mars is half the diameter of Earth. To lift fuel to an asteroid from Mars takes a rocket 1.7% the size of an equivalent rocket from Earth.

Asteroid miners will need fuel, water, food, metals, and other supplies that could be manufactured on Mars. It is many, many times cheaper to launch these from the surface of Mars than to do so from the surface of Earth.

You end up with a three-way triangle of trade between high-tech components like microchips and turbopumps from Earth, supplies from Mars, and precious metals aerobraking down into Earth's gravity well.

> Moon is possible destination because it could serve Earth.

I don't want to mirror previous stupid decisions on Earth of undervaluing potential colonies, but the Moon has very little it can offer Earth...the geology can't support the production of fuel, water, food, and metals like Mars is capable of.


> You end up with a three-way triangle of trade between high-tech components like microchips and turbopumps from Earth, supplies from Mars, and precious metals aerobraking down into Earth's gravity well.

AFAIK it makes even more sense to try and lift manufacturing out to LEO and beyond, rather than sending raw resources downwell. Earth has plenty of natural resources that aren't extracted because there's no need, but which would be still cheaper to tap into than having them sourced from space.

This is why it's fashionable now to talk about "cislunar economy". Instead of sending raw material planetside, you'd "reinvest" extracted metals and volatiles into supporting and expanding space-based capability, ultimately leading to a small and somewhat self-sustaining economy, which could then maybe trade with Earth, offering products that benefit from being manufactured in microgravity (optical fiber is one example of such product today). I imagine such space-based economy would end up being the primary trade partner for Mars, just by virtue of being upwell.

> I don't want to mirror previous stupid decisions on Earth of undervaluing potential colonies, but the Moon has very little it can offer Earth...the geology can't support the production of fuel, water, food, and metals like Mars is capable of.

Not like, but enough to matter, at least in term of fuel and raw resources. Food, well... we have to figure out how to grow it in space anyway, so this doesn't make Moon farm any less likely than an orbital farm. Point being, Moon is a pretty useful destination. It's close and has resources, which puts it in a position of being key element in expanding space-based manufacturing and operations.


The article is written assuming colonization is happening (colonization would generate demand) For colonization to happen, there is need for incentive. The article is not giving it.

Asteroids near earth provide wast quantities of water and there is cheap energy available (the Sun). Asteroids also have hydrocarbons. Asteroid mining would serve earth. Mining mars would not be competitive source of minerals for Earth.

Asteroid mining is easier to automatize. Move them even closer to earth and use partial automation and remote control.

The metals in asteroids are easier to mine because usually they have not been oxidized like they are on the Earth or in the Mars, nor are they buried deep in the ground. It's possible that there are just nodules to pick up.

Mars has low gravity, but the delta-v that determines the cost is still huge compared to asteroids. Delta-V to nearest asteroids from LEO is ~3.3. Delta-v from LEO to Mars is 9.3.

Access to Mars is also technically more challenging (Mars landers fail often. The few asteroid that have been done have been a success).


> Move them even closer to earth and use partial automation and remote control.

Move them with what fuel?

Also, the Martian missions have been far more ambitious than the asteroid missions.


> Permanently breathing bottled air inside a housing in a desert planet, having reduced lifespan etc. is not fun

Before people go they should live on a submarine for a couple years to see how they like it.


The excellent Casey Handmer covers some of the new facts that have come to light since this paper was written.

> Last week, a Nature paper (https://www.nature.com/articles/s41550-018-0529-6) was published by Jakosky and Edwards arguing that, based on data from more recent orbiters, the total near-surface reserves of CO2 are much too low to built up the atmosphere enough for terraforming. What a bummer!

http://caseyexaustralia.blogspot.com/2018/08/atmospheres-and...

He describes some of the back-and-forth dispute, but ultimately comes down pretty pessamistic on Mars terraforming.


The cost would be enormous. Much of what's consumed on the Mars settlement would have to be imported from another planet (Earth). During the early expansion phase the need for imported construction material would be exorbitant. We're talking a constant flow of goods being launched from Earth to sustain construction.

And expansion and sustainance would be very capital intensive, due to a lack of a breathable atmosphere requiring heavy duty habitats and lack of vegetation/fauna that can be harvested.


10% of the us military budget could cover it (60 billion). There's the potential to use the volatiles there to make local enclosed atmosphere, we'd eventually have the ability to grow some food locally, but yes, it's probably going to cost 100 billion. There are plans to build in things like lava tubes to protect against gamma rays.

One trick is to dig in. A large cave would provide both structural support and radiation shielding for an initial settlement. But it's true that a Mars colony would initially require a huge flow of goods from Earth - even if they get a proper farm going, they'd still need replacement parts for all high-tech equipment that's being used. That is what I think will be the primary import - high-tech components.

As for costs, dropping them is precisely the goal SpaceX is based around. The BFR isn't just meant to enable transport of people - it also aims at being able to move a lot of mass to Mars for cheap.


I'd like to see a breakdown of the kind of equipment and labor resources needed to dig out underground habitats.

To get to the point where a Mars colony is self-sufficient in producing things like heavy-duty construction equipment and solar panels could require obscene capital expenditures.

Not saying that it wouldn't be worth doing - imagine just all the technological spin-offs that would come from overcoming the challenges of creating a self-sustaining settlement on another planet, not to mention making an entire planet's worth of resources accessible to us - just that the scope of what it would require to pull off should be appreciated.

>>The BFR isn't just meant to enable transport of people - it also aims at being able to move a lot of mass to Mars for cheap.

I agree. The BFR will be a game-changer.


I suppose I shouldn't have written "dig in", where I meant less actual digging, and more of adapting existing caves and lava tunnels.

Also, solar panels I place in the list of high-tech components that would need to be imported. Curiously though, I recall reading that wind power could be used on Mars. A wind plant could be mostly fabricated from local material, with only electrical components sourced from Earth, and apparently wind power is competitive with solar on Mars - the atmosphere is less dense, but solar panels also provide less due to R^2 drop in power per unit of area with distance.

I agree it won't be easy - or cheap - but both the prospect of a colony and all the potential spin-offs make it worth it.


Interesting, thanks for the reply.

I would assume that a colony on Mars will have to rely on materials found on Mars for construction in order to be viable. Therefore after the few initial buildings built with materials shipped from Earth, there will need to be a great push to find new materials on Mars and perhaps new construction techniques to grow the colony.

> Therefore after the few initial buildings built with materials shipped from Earth, there will need to be a great push to find new materials on Mars and perhaps new construction techniques to grow the colony.

I suspect that the development will occur before the initial buildings. The political/social/economic risk environment just doesn't include the option of sending mavericks up to see if they can figure out something that works.

The rovers we have now and the rovers we are building/will build are pretty good at identifying what we have to work with, and it's comparatively easy to test a material process or construction technique on Earth before trying it while wearing a spacesuit.

At the very least, I expect we'll have a viable base of initial buildings and a fuel/oxidizer depot set up before the first astronauts arrive.


I would like to see more prototyping of techniques that could be used on Mars to create materials. It seems there is a lot of handwaving but not much real-world engineering. Before we haven't run a long-term trial for surviving in some desert on earth it would be irresponsible to fly to Mars.

There is some prototyping, but not nearly enough IMO, and it doesn't hit the news that much.

I agree about desert trials (or better yet, somewhere dry and cold near the pole). I'm not sure why this isn't done - whether it's just a money issue, or there's less benefit to be had from such test than we think?


" whether it's just a money issue, or there's less benefit to be had from such test than we think? "

I think NASA will do them but their dates for such a mission are decades away. Others who want to do this earlier are probably just not serious. With current tech this would be a suicide mission. Any little problem will kill the settlers.


On Earth, you can always airlift people at the earliest sign of trouble, so I don't think the risk is that big. And even semi-serious attempts could give wealth of data useful for actual mission.

Should have phrased this more precise: I meant on Mars every little problem will kill you. On Earth you can rescue people, no problem.

Right. Just that the part you quoted in the original reply was about Earth. Mars mission, that's almost a given. I wonder why we aren't already having larger-scale trials on deserts or near the poles.

"Current knowledge indicates that if Mars were smooth and all it's ice and permafrost melted into liquid water, the entire planet would be covered with an ocean over 100 meters deep."

This seems .. incredible. Do we have a different understanding nowadays? (The paper is 20 years old)


Significantly, this was written before the discovery of perchlorates in Martian soil, at levels that are toxic to humans. At a minimum, this means that human settlement will only be possible after a significant long-term terraforming process, not before.

This is super out of date. A lot has changed in our understanding of the livability of mars.

Where would you suggest looking for a more up-to-date overview of this sort and depth?

Such as?

Bitcoin ICOs, Mars colonization ... whatever happened to critical thinking?

Yes, exactly. Bitcoin and Mars don't belong in the same sentence.

Token sales happen on Ethereum, not Bitcoin. And ironically, it would potentially be a good way to fund space exploration:

https://www.youtube.com/watch?v=hCBki5sBw5E

If EOS can raise $4 billion over a year-long token sale, we could surely raise a few billion for a Mars colony that could change the destiny of the human species.




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