Reality check on Mars colonies

A bit of a perennial favorite for science forum members to discuss - the advisability, desirability, achievability of Mars colonisation.

I'll state from the outset that I am extremely doubtful of the feasibility of planned economies in extreme locations that have no biosphere to fall back on, nor possess the means to engage in commercially viable trade. Primarily my skepticism is for the economics but there are other causes to be pessimistic.

https://www.scientificamerican.com/article/why-well-never-live-in-space/

https://www.space.com/a-city-on-mars-author-interview

The desirability is, I think, dependent on exaggerated expectations (science fiction) and persistent underestimation of the difficulties and costs.

The long term survival and future of humanity motivations are hard to argue against but I am not convinced they are effective for making it happen - that more tangible, near term goals and benefits are needed. Because I think inhabiting space must be an emergent outcome from successful commercial exploitation of space and it's resources.

 

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I agree.

 

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Agree that the economics is dubious at this point, especially for habitations down a gravity well like Mars. Whatever is there, it would take some heavy lifting to get shipped back to Earth or elsewhere. But perhaps I'm overlooking options like retirement communities, where 0.4 Gee would be attractive. But that's really just Mars for wealthy retirees. And given Mars very weak global magnetic field, they would have to settle underground or under some expensive shielding. Really, almost every aspect of a human-friendly space there would seem monumentally expensive in upfront costs before even the first condo buyer showed up.

 

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Yes it would be incredibly expensive and I quite agree, nobody has come up with a way of making it pay its way, or at least bringing the costs down to something that humanity will be able to afford. The idea of mining other celestial bodies for minerals to use back on Earth never seems to me to stand up, given the enormous costs of the changes in momentum involved in interplanetary space travel. And I struggle to see what other economic opportunities there would be. Energy is an obvious one, I suppose, but all you need for that is satellites to capture sunlight.

 

For desirability - as somewhere attractive to live as well as ultimate defense against human extinction - I personally think spinning space habitats would beat Mars colonies. Mind, I doubt they are achievable either.

Asteroid/comet resources probably do include every known element but I would be very surprised if we will find all the ones a habitat needs as minerals we can extract easily; nickel-iron in great abundance, that can be a structural material with minimal processing but things like radioactive fissionable ones, for industry and medicine as well as energy seem unlikely except at trace concentrations. More likely to find concentrations of those on a planet that has a complex geologically active past, preferably involving water too, but we don't have evidence of uranium, thorium or other potential nuclear fuels as viable ore deposits on Mars either. I suspect a lot of critical elements will be at very low concentrations, well mixed. We will find out a lot more about what is actually there but we don't yet have a good inventory of mineral deposits - of what is present, where and in what forms. That alone tells me any commitment to colonising Mars is way premature.

From another angle I think the productivity of human labour in space or on Mars looks likely to be significantly lower than equivalent on Earth. A Mars economy needs to be a lot more productive per person than equivalent on Earth because services we count for free or very low cost - air, water, radiation protection, productive soils - are in addition.

Apart from simple lifting in low gravity I expect every kind of physical activity will be harder, not easier - and if digging a hole with hand tools requires a million dollars in PPE that seriously limits mobility and fine hand control a lot of simple jobs become slow and very expensive. Replacing the humans with machines adds layers of industrial complexity and seem likely to add to the costs and difficulties rather than reduce them.

For all that it is currently out of reach I do think Asteroid mining - nickel-iron is the best we are likely to get and by any ordinary standards a remarkable resource - and I think some of the problems of exploiting could be solvable.

"Changes in momentum" is a good way to put it - and good to talk to people who understand that even in-space transport is a high energy activity that will always involve far more fuel/reaction mass than payloads. Yes, push on something in space and there is no friction and it keeps on moving but it won't be going where you want; to get it to a specific destination takes significant energy and reaction mass - and complex technology.

Achieving ultra-reliable in-space rockets that, once launched, don't use anything consumable that isn't produced on site as part of the mining operation would be crucial. Solar electric Arcjet or similar, using water as the reaction mass maybe. I would look for carbonaceous chondrites rather than M type metallic - they can contain significant quantities of nickel-iron as grains and nodules within a softer carbonaceous matrix, which in turn contains significant amounts of water. Which by quantity would be the principle thing being mined and refined.

Of course any asteroid mining operation would need to be ruthless in eliminating any need for astronauts - nothing adds to the complexities and costs of doing things in space than having astronauts. It would mean asteroid mining would not, in and of itself, advance goals of human habitation of space.

Discussing asteroid mining here might be a change of topic - not sure yet how tolerant moderators and participants here are.

 

Besides energy and life support/ cost issues already mentioned, there is radiation to consider. From the sun but also high energy cosmic rays.

 

Oxygen would be a start though...https://phys.org/news/2023-11-ai-chemist-catalyst-oxygen-production.html

 

Yes, it is a significant problem for getting there as well as after arrival; any mission planners will be desperate to reduce mass requirements for rockets and radiation shielding takes significant mass. Not sure there is a solution to exposure during transport. Putting people at the core of the ship and wrapping everything else around will help but there is a limit to how much else will be carried.

Having underground habitats once there seems to add to the difficulties - and I am unconvinced lava tubes will give much of a head start. Any serious construction even to utilizing lava tubes or other natural caves looks problematic.

Accepting the risks of radiation exposure for the journey is all very well but even a few people getting cancers will strain scarce medical resources as well as divert economic resources. Human health in long term lower gravity is still an unknown too. I don't think it can be like a military action in a war zone where we can expect people to throw themselves on grenades (or engage in voluntary euthanasia if they get seriously sick) to save the others - even though any colony will be a lot like a military operation in a war zone - with Mars out to kill them.

It seems to me that whatever angle I come at it the problems with establishing a colony on Mars seem overwhelming - and I did start out with high expectations, if not specifically for Mars, for opportunities like asteroid minerals and high value manufacturing of materials that can't be produced in gravity. That is, things that have a commercial basis leading to jobs in space, leading to permanent habitation as an emergent outcome. Except maybe we should not underestimate what can be done in gravity to produce novel materials - I think there may be some better optic fibres that have been made in zero gravity (?) but any advantage over Earth made could be shortlived. Nothing seems to stand out as a commercial opportunity that isn't entirely Earth resourced other than asteroid metals - and those present serious difficulties too.

I really need to keep better track of what I read where - I usually try to have references and links where appropriate - but I do recall a survey (that I can't find again), I think US based, that rated what the public thinks should be space agency priorities. It had Meteor Defense at the top of the list and colonies lower down the list. I would put it at the top too - well above any attempts at assuring species survival (some people) by building colonies off Earth. Long term and international/cooperative in nature, still requiring lots of ongoing space tech R&D that can function as research Hothouses . Just one moderately large meteorite any time soon would probably greatly intensify commitment. I'm more inclined to support efforts to defend everyone from that known danger - more like the Swiss approach to Bunkers to survive nuclear war, which planned for the whole population, not a select few. Of course Switzerland had lots of tunnels.

 

A cycler. One ship with a lot of radiation shielding is launched and then used for every mission. Water is great shielding, and can be used as reaction mass in an emergency.

So don't have them underground. Use tents then cover them with dirt.

There are solutions to all those problems. The question becomes - do we want to pay for them?

 

Economics isn't just - or even particularly - about money; it is about how a society provides for itself and the fundamental unit of value from which all other value is derived is human work, not money. Leaving aside the Earth to Mars problems a key part of my question is can colonists do enough of everything they have to do once they are there? And when I say colonists, I mean people who intend to provide as much as possible of the necessities of life from Mars resources. Who intend to build an industrial economy on Mars.

It isn't that there that we can't imagine a solution to each problem - Mars colonies as thought experiments are interesting and fun - but I foresee there being too many problems, including big and complex ones like absolute reliability of energy, air, water, food as well as radiation proof housing.

But on Mars water takes mining, refining, transporting, storing, heating, insulating. Air has to be made and stored and transported and heated. Fun to imagine how so many tedious things might be done with hypothetical future technologies that border on magic, just use robots, yay but I tend to get stuck on what it is going take to make an abundance and variety of very mundane things like fibres and fabrics, sealants and adhesives, tanks and pipes and pipe fittings and pumps, somehow from local resources. Except they are not mundane, they are absolutely crucial to survival and the list of essential things is very, very long.

When everyone is working to their fullest abilities and it isn't enough?

 

Of course. And the amount of labor required depends directly upon the technology they have available. If they have to dig all their own homes they will never be able to get all that work done. If they have a few bulldozers and backhoes then they will be able to.

We've solved larger problems, though. I don't buy the claim "we can't solve this one." The argument "we shouldn't try" however is far more interesting, and there are good arguments on both sides.

Then you ship that particular solution from Earth at great expense and risk.

 

My point is a fully funded flag flying research base can construct buildings using equipment they brought along, the labour component of that being mostly on Earth. A colony on Mars can and must start like that but needs to establish the ability to make earthmoving machinery - excavators, bulldozers, crushers, graders - not just operate and maintain them. If they intend being self reliant and ultimately achieve self sufficiency that is the kind of economy they have to be building, from the start. Because trade is effectively impossible their longer term survival depends on that self reliance. I can imagine ongoing supply gifted to Mars from a wealthy, generous Earth persisting for a time, but not a long time.

There is not a lack of potential solutions for each problem but there is an overwhelming abundance of problems. I suspect they will be too overwhelmed already.

 

Absolutely. And that step could take a few years or it could take 50.

 

If it is to be a colony then building an industrial base has to be planned and prepared for from before anything ever gets landed there. Likely in much greater detail than anything we might do on Earth. As far as possible every conceivable problem must have the solutions already worked out, because there is no calling on the equipment manufacturer to send specialist engineers to the site to sort out unexpected problems.

Relying on going there first and working the details out later is suicidal. I think, literally.

We don't even have an inventory of the mineral resources that exist on Mars. I haven't seen a list of the minerals that would be deemed essential, let alone a list of the equipment and skills successfully exploiting them will require. A comprehensively capable industrialised economy is like a bare minimum requirement so any Mars colony plans better include building it.

 

Of course.

Well, no. None of our space programs have worked out "every conceivable problem." Apollo 13 was a great example; they were madly trying fixes on earth using duct tape and plastic bags to solve a problem no one had considered. They made it.

Right. Our sample-return missions are the first step there.

Yes. Fortunately we now have technology that makes that a lot easier. 3D printers are becoming more and more capable, and ISRP experiments have come a long way.

 

Interesting use of the terms "fortunately", "a lot easier" and "a long way".

Well, I did say "as far as possible" - and for all that it is held up as a great victory of human ingenuity and improvisation the Apollo 13 crew very nearly died and it just reaffirms to me how important planning and preparation is in circumstances where even small problems and mistakes are deadly. It takes a lot of resources, security and room for making mistakes and ability for enduring some losses to be able to jump in first then figure it out. Along with a secure means of retreat.

And yet planned economies don't have a great track record. To say I am pessimistic may be understatement.

 

No argument there. Like I said, it would be incredibly expensive, so whether we should do it is a good question. However, as to whether we _can_ - not much question about that,

 

I think a lot of problems would scale down some if Mars could be terraformed, which has been debated a lot. I recall there was a guy at NASA, Jim Green, head of the Planetary Science Division, who thought it could be done by means of a giant magnetic shield that would stop the solar wind from stripping off Mars' atmosphere. And eventually, make it possible to live on the surface without personal shielding and pressure suit. Pretty speculative and optimistic.

https://futurism.com/nasa-chief-terraform-mars

(brief summary of Green's idea)

Getting enough atmosphere seems problematic, unless we found a way to drop a lot of comets in there, or somehow find larger reserves on the planet than are presently apparent.

 

Well sure, Mars would be a lot easier to colonise if it were inhabitable...

 

Hard to see the longterm appeal of any habitat that doesn't somewhat recreate a terrestrial environment. If you want a colony that's a cross section of humanity, from all walks of life, it would probably include a fair number who aren't interested in living underground all the time. The problem with Green's terraform scheme is not just gases, but the solar wind deflector. Another ex-NASA guy, David Hammen, estimated you would need a terawatt to maintain the magnetic shield at around Earth equivalent of 0.5 Gauss. Something like 50 Three Gorges Dams.