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Comment by worldsayshi | Hacker News Reader

To me it seems that the greatest obstacle to space colonization would be maintenance and production of materials and technology needed to sustain and expand the colony. Seems like the last step for truly becoming self sustaining.

You'd need extremely small scale factories that can build everything needed for a modern civilization.

I wonder what that would take. What the smallest amount of shipments and time would be. Would guess that electronics would be one of the last things you'd learn to make yourself.

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But why should you have a 100% complete industry, a colony can trade with Earth like countries trade with each other, a colony could trade some rare resources and buy high tech stuff.

The main obstacle a colony will have is the initial buildings/bunker with all the life support and safety tech, plus extra redundancy and a backup plan if something bad happens there or on Earth .

If the colony would manage to generate enough oxygen,food, water and energy for itself that is the important first step. Next step would probably be producing the heavy parts they need for expansions like metal or similar solid materials for walls and machinery, the lighter parts could be sent from Earth.

Sure, becoming 100% self sufficient wouldn't be a reasonable short term goal but I can't imagine there being any product worth trading in the long term over such distance and given such cost for logistics?

Tourism will probably be the first private industry.

Maybe nothing worth shipping back to earth, but perhaps resources for shipping to orbit. Fuel, space ship components, or entire ships or satellites.

If nothing else, there is real estate. Might not be worth much, but there is a lot of it.

> Maybe nothing worth shipping back to earth

Helium 3 is certainly worth shipping even at a premium.

Moon-mined Helium 3 is currently a non-solution in search of a problem.

Unless there are widespread helium-3 fusion reactors, the demand for it is about $2000/liter for mostly scientific and imaging purposes. Even then it’s a sort of a niche driven price since when the US was willing to bother decaying tritium for it it was like $100 a liter.

Making a helium-3 fusion reactor is a tougher problem than mining on the moon. And even then making helium-3 on earth is cheaper than going to the moon to mine it.

Mining the moon for Helium-3 would be something someone would do once a colony is established, not a reason to establish one.

Probably the most lucrative thing to mine on the moon is water.

I imagine people used to think that when it was France trading with China beyond things exclusively in China like silk. Prices go down over time.

Also it might be worth it for gold.

Water possibly could be of great value in the future? Moon has plenty of drinking water. Maybe gold, not sure if there’s gold on the Moon?

What happened here on earth in your imagined scenario where it's worth importing water from the moon? (and how did we survive that long enough for a market to develop?)

To be fair, I hesitate to spend €1 on a liter of spring water today. However for a single drop of moon water I might trade my car, sex, or significant work.

Refined aluminum was once scarcer than gold, and aluminum jewelry was extraordinarily expensive.

Desalination is expensive but i think it might be cheaper than moon water.

I was about to upvote you, then realized desalinization is not even expensive anymore. Shipping water from the moon to earth is just a really really bad idea. Ha, even burning the fuels to send the rockets into space would create more water here on earth than we could bring back. Fuel + Oxygen --> carbon dioxide + water

Ah yes, the entirely viable project of moving water from a bone dry vacuum rock to a planet 2/3 covered by water.

I'm not sure it would be viable to return gold from the moon even if the moon was made of solid gold.

Yeah that's a good point. At least it could be used locally by the colony then.

just push the whole thing into the pacific... probs be alright, right?

Ah yes, the entirely viable project of moving water from a bone dry vacuum rock to a planet 2/3 covered by water.

Water as a space resource is primarily talked about for use in space.

I'm not sure it would be viable to return gold from the moon even if the moon was made of solid gold.

It turns out it's a lot cheaper to return stuff from the moon, than it costs to send it to the moon. This is especially true if the stuff is dead, and you don't mind subjecting it to 10's of thousands of g's and you can use electromagnetic accelerators running in free vacuum on the surface, instead of rockets.

Pure drinking water literally falls from the sky on this planet.

*for now

When/How do you anticipate that stopping? Unless the entire planet freezes over, then you'll have even more fresh water in the form of ice. As long as it's above freezing, and 2/3 of our planet is covered in water, it will be raining somewhere.

He3 would be a very profitable export for the moon if we ever develop commercial fusion power on Earth

We put helium in children’s balloons and it’s down here with us at the bottom of the gravity well. It’s cheaper to refine the Earth’s helium than import it from the moon. And we have no use for Helium 3 now nor for the next 30 years.

http://www.antipope.org/charlie/blog-static/2010/08/moonshin...

> Firstly, nobody's built a commercially successful fusion reactor yet. ITER plan to build a working test-bed; it's logical successor would be a working prototype first generation power reactor. There are huge obstacles to overcome, not least in developing neutron capture techniques and breeding D/T fuel. These are engineering problems (sorry, annoying paywall) and theoretically amenable to solution — but at a price of billions of euros and decades of work, and even then, it may turn out to be too costly to be a viable competitor for well-understood fourth generation fission technology and a mature waste disposal/fuel recycling chain. And that's before we look to a speculative second generation reactor, running on a different type of fuel, that — because of the higher Coulomb barrier between He nuclei — requires a far higher temperature (on the order of 500M to 1Bn degrees celsius, rather than the relatively chilly 100M degrees C required for D/T fusion).

> Given the average generation time for a new reactor technology of 20-30 years, and development costs on the order of $50Bn-100Bn per generation, we won't be even thinking about prototyping an He3 reactor until 2060 at the earliest.

Looks like we both touched a nerve there but I’ve no idea why!

I imagine that in the beginning you will have mostly scientific facilities , like telescopes on the dark side of the moon(you will need scientist, technicians and other stuff around this big telescopes).

There could also be facilities for experiments that can't be done on Earth, like things that can grow better on low gravity, there may be materials/gases that are rare on Earth and we could grab from asteroids so having space stations and bases around the solar system would be helpful.

> the dark side of the moon

BTW, this isn't a real thing

> BTW, this isn't a real thing

Yes, the dark side of the Moon is a real thing. It's the side that doesn't get Earth-lit nights.

That's an odd convoluted definition that I've never heard of before.

I think the point the other poster was making is that "far side of the moon" is far more specific, accurate and useful term.

> That's an odd convoluted definition that I've never heard of before

It's a “definition” in the sense that it is a description semantically equivalent to what the phrase “dark side of the moon” has always referred to; it is not, however, a description of the etymology of the term, which derives instead from the long established use of “dark” to mean mysterious, hidden from knowledge, obscure, occult, etc.

In this case, silent side of the moon is more useful, since that's why it's so attractive to scientists.

What I meant by dark side is "The hidden side" since that side is always hidden from Earth (similar when I say your dark side i do not mean you have a side that is not in the light), I am aware some people may misunderstand this expresion, but "far side" is not as expressive since it is missing the part of "always hidden"

That's the same dilemma some one making a new car like Tesla has to face.

So you first make something the rich people want. Like luxury residences in spaces, Elysium like. Like really really affluent neighborhoods for ultra rich. Tourism is another part. Make people go to space, stay for a few earth-days, have them see some spectacular astronomical phenomenon. Sky size theaters, Toy space shuttles like we have dashing cars, Disney land like attractions etc etc.

The other part of course is permanent science labs, where you do high quality research and development. Something like the Large Hadron Collider takes a lot of real estate and resources on earth to build. Eventually that kind of work can be done in space. That will make a lot of smart people want to work in space.

Of course since resources are plenty in space, and energy is just pointing you array of panels at sun. I'm guessing due to the economics of it, a lot of other people might want to stay and work there. Like electricity strapped countries, might want to manufacture in space.

The use cases are endless that way.

Eventually you extend it to everybody else.

> over such distance and given such cost

The moon is just a few days away.

The costs are not a given. With new better tech, then can come waay down.

Also note that the freight ships need not be manned.

The most obvious trading I can imagine would be selling in-orbit manufacturing of spacecraft and space facilities to planet-based interests, in exchange for hi-tech electronics and food.

digital entertainment

One of the reasons to establish off-world colonies is to allow persistence of the species in the event of a catastrophy making the Earth unlivable. Given the history of extinction events found in archaeology this isn't an entirely unreasonable thing to plan for.

In that frame, a colony that can't survive (or has a reduced chance of survival) is of lower utility than one that can be effectively independent.

As far as I know, Humans need lots of gravity to develop, so any settlement could not reproduce, at least until means to counteract the effects of microgravity are discovered.

You spin your O'Neill cylinders, that's how you get gravity.

O'Neill cylinders don't work on the moon.

"Aw, Mom, why can't we go live on the moon with Dad?"

"Now, Billy, you know your bones and brain need at least .85G to develop properly. You can go live with Dad when you turn 16."

Would be more worried about this eventually happening the other way around.

"Aw, Mom, why can't we go live on Earth with Dad?"

"Now, Billy, you know your bones and muscles are used to lunar 0.16G, and won't support your body in full 1G. Your heart isn't strong enough for those conditions either."

See also: Belters from The Expanse.

Yup, also Andy Weir's Artemis, and to a lesser degree Larry Niven's everyone-except-Jinxians.

Also the anime Planetes had touched this topic, AFAIR.

At this point in time, any mass settlement in space won't involve going down another gravity well.

Pulling stuff out of a gravity well is enough work as it is. Mostly you will have people living and working in neighborhoods, in space, just like you have cities and lot of empty unused land between them on earth.

Like space cities. Then cluster of space cities, then may be a region full of such clusters etc.

Lunar G isn't microgravity. We genuinely don't have the data, which is why this, Eucropis, and subsequent work is a big deal.

You can still build something that spins at 1G though. It just isn't a cylinder anymore, but something more like a continuous racetrack.

Easier said than done

https://m.youtube.com/watch?v=EHKQIC5p8MU

Pretty much any project that involves humans settling in space in itself is a long shot goal by todays terms.

Even if you start mining the asteroids any time in the coming decades, it won't be any thing less than a century after that, until you put humans into permanent colonies.

>Humans need lots of gravity to develop

I don't think reproduction of vertebrates has ever been tried in space. Definitely not humans. It simply isn't known how growing up in moon gravity or no gravity at all affects people. They most likely would never be able to visit the Earth, but maybe they can live healthy lives regardless. Or maybe it's impossible and the fetus dies in the womb. It simply isn't known.

Humans certainly need some gravity but whether lunar 1/8 g or martian 2/5 g is enough is something we have no experimental data on.

Very minor correction that does not affect your point: lunar surface gravity (1.6 m/s^2) is only about 6 times weaker than that of earth (9.8 m/s^2), not 8 times.

>>But why should you have a 100% complete industry, a colony can trade with Earth like countries trade with each other, a colony could trade some rare resources and buy high tech stuff.

Queen Elizabeth the Second, by the Grace of God Queen of this Realm and of Her other Realms and Territories, Head of the Commonwealth, Defender of the Faith &c. To ALL to whom these Presents shall come, greeting:.....The Moon Trading Company : )

They need a way to get pure vitamins, fat etc and then mix them on the Moon. Live on shakes or something at least until all is solved.

Robert Heinlein's novel The Moon Is a Harsh Mistress has a lot to say about a space colony (in this case, on the moon) depending on resources from Earth.

https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress

You can ship a 40ft container with about 25t capacity for about $2000-$5000 between any major ports on Earth, and probably for even less for bigger volumes.

SpaceX BFR has about 100t capacity to Mars. While the total cost of a Mars mission has not been publicized, I suspect it would be fair bit more than $20k.

Biggest container ships these days carry about 20k TEU, or about 500000 tons of cargo. You can try putting that number to the rocket equation just for fun.

>SpaceX BFR has about 100t capacity to Mars. While the total cost of a Mars mission has not been publicized, I suspect it would be fair bit more than $20k.

While we don't have SpaceX numbers, Zubrin said in 2012 that if given to NASA Mars Direct (A Mars proposal from 1990-1991, updated in 1996 in Zubrin's book The Case for Mars) would cost 30-50 billion but a private company could do it for around 5bn. That still put you at several million dollars per metric ton delivered to the Martian surface BUT that included all design and administrative costs.

You can see some of the Mars Direct figures here http://www.astronautix.com/m/marsdirect.html

We also know what SpaceX quotes 90 million dollars for 16.8 metric tons to Mars with Falcon heavy which puts us at 5.35 million dollars per ton which is already quite a bit cheaper than the most optimistic Mars Direct figures. https://www.spacex.com/about/capabilities

BFR should be able to do way better than that if it ever becomes a viable system.

Does Mars make a particularly good outpost for asteroid mining with its much lower gravity well, and the fact that if you fuck up and de-orbit an asteroid you’re not potentially destroying a large swath of populated land below?

There may be refining steps which you would want to do on the surface vs in orbit, and getting the raw ore down and refined product back up would be substantially cheaper on Mars.

Probably it wouldn’t be worth building a colony in the first place for just this economic benefit, but once you have the colony, you can exploit this advantage?

We're not even self-sustaining on Earth.

Fair point. Perhaps forcing us to be on Mars can teach us something about sustainability here on earth. Here's hoping.

We already have sustainability on Earth; it's just that it's expensive. There's no new science or knowledge required, just a lot more investment.

But, profit margins.

Science and knowledge can help make it cheaper, make those profit margins look better, and have it happen more.

We also have significantly more people on Earth though. If anything, more planets makes us more self sustainable in the future.

Not likely; the population will grow, becoming interplanetary just means we'll have more places to grow. It won't move the problem, not unless there's more emigration than population growth, and you can already see how that works on earth.

Most experts say the Human population will peak at some point.

The project to put even a couple of people on the mars surface, let alone let a couple of hundred live there, is currently too demanding to even attempt. Only vague plans exist.

That's one of my arguments for space colonisation.

In the process of colonising other bodies and planets we'll learn how to be more sustainable here. In other words we would use the promise of new resources and exciting new worlds to learn how to avoid destructing our own.

I'm with you on this one. Along the way on the amazing expansion into space, we'll rediscover the critical importance of maximizing efficiency in meeting our basic needs. It would serve us well to get everyone associating that level of efficiency with our greatest feats of technological progress.

Also, what better way to get kids on board from a young age? "Susie, if you really want to be an astronaut, you must learn to manage your downstream recycling better!"

I don't understand human psychology well enough to be sure, but I could see it easily going the other way for some people. "We've got a self-sustaining colony on Mars! Finally, we can stop obsessing over such petty terrestrial details like CO2 and plastic waste that we once thought were so important to our species."

I can easily see it going both ways at the same time.

Space colonization will be a strong forcing function for developing high-efficiency technology. Hell, it'll force us to comprehend the energy budgets to much deeper levels. I could see this resulting in a lot of new products and new ways of doing things.

At the same time, if on the social/cultural level, people start to feel that Earth is just but one place available to people, I can imagine them naturally care less.

Solving just about any of our sustainability problems on earth will be easier and less work than establishing a self-sustaining colony any place else.

Learning to swim in a shallow pool is _easier_ than just getting thrown into the deep end, but it's not faster, and the learning isn't as likely to occur.

Why would colonizing the moon in a self-sufficient way be faster than doing the same thing on Antarctica or the bottom of the ocean? The only thing I can think that would make it faster is that people will romanticize space colonization so much that they will volunteer for a suicide mission.

In reality most people who are unable to swim and are thrown into the "deep end" would just drown, making it quite unlikely that any learning will occur ever again...

Unless one of the byproducts of space colonization is the retrieval of a super virus capable of wiping out large swaths of humans rather quickly, I don't feel the domestic paradigm will shift significantly enough.

Smallest scale fabs can fit the whole cycle in one building: wafer production, CMP, gases facility, front-end, back-end and etching/deposition/doping lines. Some 180nm level fabs are like that, and rely on equipment unification in between back-end/front-end/etch/deposition/doping lines.

Big questions:

1. How to make wafers in low/no gravity? Without convection, you can't purify silicon. May be you will rely on an entirely chemical process to grow a crystal?

2. Expensive gases will have to be recycled, not neutralised and disposed.

3. How will you do wet etch in zero/low gravity? Will you go plasma only?

If you want gravity, you use centrifuges. Not really a problem.

And this gives you the benefit of applying exactly the force you want. I'm no materials scientist, but I imagine this could allow for some potential gains in efficiency/quality/whatever.

is this kind of simulated gravity sufficient for the convection processes described?

I think Einstein might have something to say about that one.

https://en.wikipedia.org/wiki/Equivalence_principle

Not sure how this supports or refutes GP claim ...

EDIT I mean - we’re talking about convection right? Which I understand to involve circulation of air currents ... does your link have anything on this topic? I guess with a large enough centrifuge there might be no difference but it was unclear whether what was being referred to was large habitable centrifuges or the type more commonly found in labs ...

Linear acceleration is equivalent to gravity. Spinning is not; it introduces the Coriolis psuedo-force or however you prefer to look at it, which allows it to be distinguished from gravity.

I concede the point, but counter with the fact that completely flat gravitational fields are implausible, so you could technically distinguish between linear acceleration (which has the same acceleration everywhere) and acceleration due to gravity (which doesn't, and hence generates a tide).

The effect on a stationary point sized object is equivalent in all three cases. When your object moves then the spinning artificial gravity can be distinguished. When your object is no longer point sized then both gravity and spinning fake gravity can be distinguished from linear acceleration fake gravity.

I concede you have out-pedantic'd me. :)

> Not really a problem.

Your gravity vector will have to be uniform, otherwise your crustal will turned curved.

Your centrifuge will have to be either very large, or you will have to find out how to do that without convetion

NASA have been looking at this almost since the Kennedy speech. e.g. (1989) https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/198900... "Lunar production of solar cells"

(Contains some handy tables of relative abundance of substances at the end. Oxygen is really plentiful, it's just attached to all that silicon and iron.)

To me it seems that the greatest obstacle to space colonization would be maintenance and production of materials and technology needed to sustain and expand the colony.

Zubrin's estimate of this in The Case For Mars is a half million people. That's an estimate for the minimum size of the population which can support the knowledge base required to make everything to sustain a modern industrialized civilization.

You'd need extremely small scale factories that can build everything needed for a modern civilization.

It's been demonstrated that a single person can build up the infrastructure of an 1800's colonial village all by himself, up to and including a blacksmith's shop. That guy from Turtle Island Preserve could do it, dropped into a forest with a single knife. There's a YouTuber who does all that sort of stuff without the knife to begin with.

It will be harder to do such bootstrapping on Mars, of course. I'm not sure that the half million estimate above included chip fabs. I somehow doubt it.

>I wonder what that would take. What the smallest amount of shipments and time would be. Would guess that electronics would be one of the last things you'd learn to make yourself.

If I recall correctly the number quoted from E. Musk on an early Mars colonization presentation was 2 cargo ships per full colonist ship. But that's only for being water/air/food/energy self-sustained. The assumption is that large shipments of high-tech products will continue for a while. Maybe something like solar panels/basic air turbines can be produced on the spot provided with either the raw material or mining equipment. The same probably goes at least for simple electronics( like e.g. various sensors for monitoring the colony), lots of appliances can be made in a crude way( think stoves, furnaces, maybe fridges?).

> You'd need extremely small scale factories that can build everything needed for a modern civilization.

It's not as much as you'd think, specially if you can survive on the first couple of decades with regular shipments from earth, mostly for very advanced materials and electronics.

A lot of manufacturing capacity in our society is redundant and focused on non-essential items. In addition, some manufacturing processes are complex because of the scale of our society but could be made simpler for a small colony, especially if you are not worried about details or finishing quality and approach it from a more utilitarian perspective.

I think you underestimate how complicated even simple machines are. Making lubricated ball bearings for example requires high quality steel, precision manufacturing and chemistry that is not trivial if you don't have access to oil.

Yes, that is how we do it now. But what if you only need 3000 ball bearings a month, would other process be more feasible, since the fact it is not economical at scale can be ignored?

You still need high quality source materials and low mechanical tolerances even if you make them by hand. You obviously don't want to recreate planet-spanning supply lines, but even getting good steel from ore is highly nontrivial.

I think the tech that I'm most interested in for the purpose of colonizing other worlds will be 3D printing. In its current form it's no where close to good enough, but if we stretch our time horizon to hundred plus years I do think we can build 3D printers powerful enough to make everything we need to mine and sustain life on other worlds.

Let me know when your 3D printer can make it's own electronics. Also, mining equipment... I mean, wow. I suppose sintered metals might be possible but there's still the refining of raw materials. I guess my point is that the supply chain needed to build a 3D printer is probably enough to sustain things without the 3D printer.

That's not to say they wouldn't be useful. I really like being able to sketch out whatever bracket, holder, candy dish, etc that I want and print it. That would be very useful on a world without a huge economy providing every little thing you might want or need.

Mars is a better space body for a colony. I suggest reading "A case for Mars" by Robert Zubrin.

Shielding off radiation is hard too, on Earth you gave an atmosphere and a magnetosphere. On the Moon or Mars its much harder to do the shield effectively

There are some caves on the moon that provide shielding and, probably, water since they have perpetual shadow inside them. They can be very attractive places to build future colonies.

And if you don't have caves you can just pile dirt on top of your habitats. Dirt is one potential export from a lunar settlement. Everywhere outside the Van Allen Belt needs radiation shielding and dirt doesn't mind being violently accelerated in a mass driver.

Dirt is abundant near every solid surface. Not sure it's a valuable commodity but regolith glass would be more interesting. I'm curious about the metallurgical processes we can do easily on the moon.

Making glass and aluminum should be relatively easy on the surface of the moon.

I think we’ll see robust shipping routes before completely self-sustaining colonies. To the point where missing 2-3 shipments isn’t a huge deal.

And that pesky radiation slowly killing you.

The unshielded radiation dose for a round trip Mars expedition with 18 months spent on the surface is roughly equivalent to the life time dose allowed for a worker in the nuclear industry. The risks are completely negligible compared to the 50% or so chances of not making it back to Earth.

https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays...

One of the first mass products of a colony is likely to be Methane and simple hydrocarbons like ethylene which can be further used to produce polyethylene, an excelent shielding material that can reduce the radiation to earth levels if applied in thick blankets.

Many concepts for permanent settlements on Mars or the moon envision tunneling under the surface to achieve radiation shielding.

Of course it would help to develop better treatments for radiation exposure.

Replicators. Feels like no one watches Star Trek anymore. Those writers had more time to think about this stuff than most science labs and engineering teams imho.

>Those writers had more time to think about this stuff than most science labs and engineering teams imho.

No, they didn't. They came up with transporters to save money not having effects shots of ships taking off and landing, and replicators are basically the same, a prop meant to save a bit of money while looking "futuristic". Replicators and transporters violate physics (thermodynamics, the uncertainty principle, E=MC^2) and cannot exist as depicted in Star Trek. They spent zero time working out the science because they're television writers, not scientists.

The best you could do in the real world is 3D printers and fabbers. But directly converting energy into complex physical structures in a way that isn't insanely less efficient than physical manufacturing or agriculture? No.

What would 3D printers look like in 100 years?

Polymimetic alloys

Oh Geez! I work in Industrial Automation. I have had a front row seat to the gains made over the last 20 years that nobody ever predicted. I give factory tours regularly and most people with decades of experience have their minds blown at the efficiency gains in industrial processes.

It has nothing to do with violating physics. Its just about being part of hyper-connected systems where incremental change, is happening in a thousand different places along the entire assembly line that add up to huge gains that nobody can imagine individually.

Are we going to see things materializing at button press in an instant? No. But we are going to get damn close.

Replicators are fictional technology that is either straight impossible to build or requires ludicrous amounts of energy.

I had to double check to make sure I wasn't on reddit after reading this. Good work.

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