What is the lowest tech level that could sustain life on Mars or the Moon?

Question

Inspired by this question, which asks how we could achieve a "backup" of human life. Mars came up as an obvious idea, but with the caveat that it is nigh impossible to keep a Mars colony running independently from Earth, due to the enormously long and complex supply chains for, well, basically anything.

But is it completely impossible?

Let's assume that once we are established on Mars, we don't want to leave again - and we are ok with giving up a lot of our current technology level.

Our goal is simply to survive - in a way that is sustainable and independent long term, if possible indefinitely, if not, let us aim for at least 100-200 years.

We'd need (in about that order...):

• pressurised environment
• breathable air, i.e. a sustainable O2-C02 cycle
• temperature control, i.e. heating
• drinking water cycle
• food cycle
• shelter

What is the minimal technological level to achieve this?

I'm going out on a limb here in suspecting that you could probably do all that without modern computers. What else could we do without?

Note: getting to mars, and setting things up can use more advanced tech level. But once set up, it should be sustainable independently.

Answer 1

We're not quite there yet

If your goal was a 1-5 year mission, then sure we could probably pull it off with more or less current technology, but all the of the computers and polymers that make space colonisation feasible, all are have shelf lives of WAY less than 100-200 years. Microchips are so small that their internal components begin to slowly weld into a useless mass after a couple of decades; so, even if you pack extras, your replacement parts will be useless by the time time you need them. Most Polymers slowly degenerate when exposed to the radiation and temperature conditions seen on Mars or the Moon. So, to go 100+ years, its not enough to build the colony, you need it to be able to replace everything that might break down over time.

The big impetus in sustainable life on Mars is that too many of our manufacturing processes still require large specialized equipment. You can't make the Martian equivalent of a shack without a massive, expensive, and complex system of refining and manufacturing processes... and building the kind of infrastructure on Mars to make this happen will require a few break-through technologies.

Any which way you add it up, you will need a new power source. Mars does not have fossil fuels, enough wind to turn a turbine, active tectonics, or flowing water which rules out most of the power sources we have here on Earth, and solar just won't cut it for anything more demanding than keeping the lights on. So, you will probably need to establish an abundant nuclear fuel source on Mars/the Moon if you want to start working in the power requirements needed to smelt your own glasses, alloys, and such. And the kind of nuclear reactor you use has to be some kind of future tech because Luna and Mars do not have the natural resources to make a traditional nuclear reactor. You'd either need to come up with a new way of enriching heavy metals, or you'd have to improve fusion to the point that you can turn an energy budget profit from something like hydrogen-1 or helium-3, and do it well enough to not need a massive infrastructure to support it. You'll also need a cooling and regulation system other than water and carbon rods do to resource scarcity. A salt based reactor might be fine though. Salt exists in abundant concentrations on both Mars and the Moon.

On top of this, you will need to address the issue of just how much it would cost to build all the needed factories on another planet. We are talking millions of tons of infrastructure. This means that you either need to have a new and better form of space travel making transportation in bulk to Mars orders of magnitude cheaper than it is right now. Even then it would probably take over a century of colonization to build up the settlement to any level of self sufficiency.

Alternately you could introduce advancements in "3d printing" to rule out the need for big factories. If you had something approaching the likes of Star Trek style replicators, then your colony would not need big factories for each of the thousands of things it needs to produce, you could just have a single habitation building full of replicators replace your otherwise complex production lines.

Answer 2

Frame challenge: It's not about technology, it's about energy

Mars has about 1/4 of solar energy income than Earth, and no converted forms like fossils, elevated water or accelerated gas that could be used with relative ease as we have here (hydro, wind, coal). It's unknown as of now whether Mars has fissile matter in enough quantities to warrant a nuclear plant with local power supply, but even if it does, it still has to be first mined, then refined, then packed into fuel cell units, before being put into a reactor, and also with the thin Martian atmosphere cooling that reactor would prove extremely hard as well. So, a colony on Mars is limited to solar power.

Second step: everything we have to do for our life support also consumes energy, thus we would need at least 4x the area dedicated for solar converters than here, on top of requiring the same source to mine materials for supporting any industry we'd need to maintain the colony. This means the colony would be extremely dependent on solar batteries, and also would have to spend no less than four times the energy to produce those solar panels first. This means that maintaining constant human presence on Mars is currently not possible, but not by technological, but energetical reasons. Building an automated solar farm might be possible with current tech, assuming enough batteries would be installed to supply a single mining robot with some rudimentary processing structures that would in turn use that energy to make more solar power units. I think though that this technological edge is not reached by the humanity yet, as even a "fully robotic" industry here still requires human maintenance, and there would be none on Mars in this scenario.

Third step: maintenance. It's not just that the chips get welded, it's also that the fine Martian dust would be a huge obstacle by blocking sunlight from hitting those panels, interfering with open contacts (the dust is said to be conductive), accumulating in the insides of a robot that would mount new solar panels, maybe by some other means as well, and all these should be somehow controlled by the fully automated facility. On top of that, the facility has to store enough energy to relaunch itself from at least a two-day blackout similar to the one that hit Opportunity: Or maybe wait in hibernation until it would clear again. Still, with humans such a facility must not stop, or else the base would die off.

Fourth step: thermal balance. Even automated devices require both cooling and heating on Mars, to not get out of working temperature range; with humans around the balance would also have to account for pressurized areas and any other biomass that would be present there, with its own range of temperature to retain functionality (plants, fungi, actual water, whatever else). All this would require excess energy to maintain, and we are already on a very strict budget.

So in total: we are only a tad away from the goal technology wise, but we are very far away energy wise.

EDIT: this was covering only Mars, for the Moon we probably have a harder time as energy downtime on Moon is a lot longer (14 days), but there's less dust and more energy to boot, making the actual problem with Moon be energy storage, not gathering. And our energy storage devices leak faster than fourteen days, especially if loaded. We still can solve the problem by employing a complete power grid across Moon, but this is out of our reach material wise.

Answer 3

1950s-ish Technology

Now - there's gonna be a bit of handwavium going on here - but it's predicated that there was an absolute push to get to Mars.

We are also assuming that we have the technology to get to Mars - as manned space flight wasn't a thing until 1961 and we still haven't gotten to Mars as of 2023.

Why the 1950s?

Okay - let's go through the technologies required:

1: A Pressurized environment capable of supporting human life - doesn't need to be 1 Bar, could be like an airliner - pressurized to 8,000 ft - This sort of tech was 1930s

2: Oxygen/CO2 - so this is a two-parter. Either you need to use the exhaled CO2 for growing food (which is preferred) generating the Oxygen or you need to scrub the CO2 using CO2 Scrubbers and generate O2 - Plants are obviously 1950s tech, CO2 scrubbers are 1948 and at a pinch. Electrolysis of Water could be used to produce Oxygen (there's Ice on Mars - so that could be used). Venting CO2 to the atmosphere is a possibility too, but that might be a bit too much faff without computer control.

3: Electricity - The Big One. All your main systems, heating, electrolysis if you use it, light etc. need POWER. Burning anything is going to use up precious O2, so you'll want Nuclear Power. This is where the 1950s come in. The first nuclear submarine SSN571 was launched in 1955, and a Nuclear Submarine is a great proxy IMO for a Martian colony.

4: Drinking water - You could use the heat exchangers for the nuclear reactor to create condensed, potable water for drinking from Martian ice.

5: Food - Hydroponics with artificial lights was done successfully in the 1930s and high pressure sodium lamps were invented in 1959.

That's the bare minimum.

And I don't believe you need computer controlled anything. Computer control in general does 3 things:

• Measures input and output metrics more accurately
• responds to small changes quickly
• this leads to increase in efficiency and precision

So long as we can spam nuclear reactors we can accept that we are going to run everything analogue and that there is going to be a decrease in efficiency, which we are going to make up for with an excess of power.

We had heavy industry before computers. Computers merely help us be better at it.

In terms of Industry, the main things we would need is, IMO, the ability to mine and refine iron ore and the basics of machining (welding equipment, a milling machine, a lathe, a set of micrometers and a set of reference blocks). With that and suitably skilled machinists, you should be able to do most things that would be required such as make tools, repairs, other machines etc.

The only thing that will be an issue would be a replacement for all the organic chemical products that come from fossil fuels. But as I said, a bit of handwaivium is required.

Answer 4

As a frame challenge: the hard part of establishing a self-sufficient settlement on Mars is not technological advancement, as it's usually defined. As long as you can maintain a heated, pressurized environment and have a non-oxygen-using power source (solar or nuclear will do fine) you have "enough" technology for the task.

No, the hard part of a self-sufficient Mars colony is the preposterously large supply chain needed for modern technology. Make no mistake, there's no technology that will reliably last the centuries required without replacement parts, or maintain the colony's biosphere with such precision that it doesn't need replenishment from outside. The colony will need to produce raw materials and refine them every step of the way and that means millions of people: farmers, miners, technicians. Countless factories turning out everything from computer chips to colony domes. Chemical plants for processing Martian regolith into the gases and fertilizers the colony needs. Titanic greenhouse farms to produce food and oxygen. These things aren't difficult because they're on Mars or because they're extremely sophisticated - they're not markedly different from what people have been doing for centuries on Earth, except for being indoors. They're difficult because they're big.

If you could ignore the difficulties posed getting things there and bootstrapping the early settlement, a Martian colony could be established today, or fifty years ago. It would take a tremendous amount of effort and many people to make it happen, but it could happen. Unfortunately you can't ignore those difficulties and it's not practical to move that many people or that much equipment, nor do we know exactly how to handle them when they arrive. What takes highly advanced technology is not self-sufficiency, it's bridging the gap between landing the first crew and becoming self-sufficient.

Answer 5

I'd say its probably not possible to make living on Mars sustainable long-term with a relatively low level of technology. We can't even create a sustainable human scale enclosed environment on Earth yet (Biosphere 2 being an example of a failed attempt). Whatever tech is required to pull it off, we don't have it at the moment. Its highly likely sustainability would require some highly advanced tech.

Answer 6

Current or far future, depending on the long-term effects of Mars' reduced gravity on the human body. 0.38g may or may not be unhealthy enough to make things work, we don't know. But it is low enough that it is likely that we would need some kind of solution to deal with it if we want a permanent colony to survive.

Air, water, food and energy are all problems that in theory we could solve with today's technology. The problem isn't that, but the practical solutions and the resilience. A single base has a zero margin of error on any of those. Multiple bases could help each other out (or take in refugees from the failed bases).

Water is potentially the crucial factor. If we can't find a source of water on Mars, than everything that's lost to the environment is lost forever, and that means sooner or later there'll be not enough of it. But with enough care and redundancy, we could make a colony work for long enough that they can figure something out (say one or two centuries).

But gravity is something that we do not have a solution for with our current level of technology. If this turns out to be a serious problem, there's nothing we can build that can fix it.

Answer 7

Ask "Elon". He and his organisations must have about as good an idea of the (out of this) real world factors involved.

While they will have available ongoing high technology input, their aim is to be self sustaining on Mars.

I've seen it claimed that after a civilisation-destroying planet wide catastrophe (maybe nuclear war, or not too too too large asteroid, ... ) that it would take about 30 years (!!!) to re attain current technology levels. Even if it was two or three times that you MAY expect the cavalry in about your time frame. However, their focus may be diverted by 'other matters' for a century or so.

Mars & Luna are quite different propositions.

• Mars is VERY hard to get to and harder to get back from.
  It has a minimal atmosphere by Terra standards, but what there is of it is suitable for making into rocket fuel, provided an energy source is available. Solar power is far lower than Terra. Nuclear power is the obvious choice. Water is available, certainly at the poles, and quite possibly elsewhere in abundance. One could conceive of creating self supporting eco-systems with a good energy supply - probably nuclear. Elon does.

• Luna is far closer and easier to access - not just in overall energy budget but in trip times. There appears to be water at the 'South' pole - not obviously anywhere else. Solar energy is more available than on Mars but the requirements to either import or manufacture the requisite systems is daunting. Again, nuclear power is the obvious energy source, but utilising it to create a viable ecosystem seems far more demanding.

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The Mars Colonization Delusion: A Critical Analysis of Elon Musk’s Starship and Space Projects [here] or here (different format).- about 40 pages!

SpaceX ambition of colonizing Mars - Wikipedia

When SpaceX's Starship is ready to settle Mars, will we be? (op-ed)

Google search spacex mars survival analysis