[pookha]

The moon has trillions of dollars in water, helium, and metals (rare earth, titanium, etc). It's an f'ing goldmine and controlling said resource will be something hostile authoritarian regimes (China) would seek out. There's simply no excuse that the US should be this bad at making a system to reach the moon. The Chinese have committed insane sins and dropped massive amounts of space hardware on the earth (luckily it landed in the ocean). We should be dunking on them but instead we've got this buffoonery?

[NikolaNovak]

I have never found any math that made trip to the moon for materials even remotely wortwhile, by like orders of magnitude, not just today with today's technology, but for any foreseeable future we can meaningfully discuss. Water in particular is an unfortunate one to start with, given its abundance and ease of extraction on earth, vs absolutely positively ridiculous efforts to obtain them from the moon. But everything else from metals to obscurely valuable versions of Helium, seems to fall apart as soon as we go from "Look! Up there in the sky! Minerals!!!1", to "let's do a back-of-the-napkin math along any of the materials, science, energy, or money axis"

I enjoy using traditional cold-war bogey-men to scare ignorant politicians into accidentally sponsoring real science as much as any other person, I do, but... as long as we're not actually buying into that sillyness, right?.... right?

[SCM-Enthusiast]

you should read the book delta v. The only time lunar mining makes sense is when there is a cislunar orbit economy. The delta v required to put things in orbit from the moon is a fraction of that of earth. So, if you have a vibrant manufacturing enviroment in space (Semi conductors, and other deposition methods) which space is more suited for, then the moon becomes a better place to source your materials from.

[usrbinbash]

> So, if you have a vibrant manufacturing enviroment in space

And how does this "vibrant manufacturing environment" get into space? How is it supplied with personnel, food, water, spare parts, etc.?

Let's just focus on one component, shall we? The Moon only has 1/6th of Earths gravity, but to get stuff away from the Moon still requires a launch. That launch requires fuel. There is no fuel source on the Moon, so even if we had production facilities there, there are no high energy raw materials for them to process.

So where does the fuel come from? How about the only place in the solar system we know where we can make rocket fuel: EARTH!

So every liter of rocket fuel used to power launches to supply raw materials to a "cislunar orbit economy", first has to be transported to the moon by launching it from Earths gravity well.

So, where is the gain in efficiency exactly?

Also, where would this "cislunar orbit economy" find a market? The vast majority of people are here, on Earth. So even if there was a way to supply such an economy with raw materials (and energy, and personnel, and so on), the products would still need to be transported to Earth, adding a huge additional cost to everything manufactured. How is this supposed to compete with products made on earth exactly?

[SCM-Enthusiast]

>fuel

Hydrogen and oxygen can be made from water, and methane can be made from regolith and water.

>where would this "cislunar orbit economy" find a market?

The uniform distribution of microgravity lends itself to advanced manufacturing methods that cost hundreds if not billions of dollars to replicate here on earth. soooo many of earths manufacturing methods use very expensive means of creating the vacuum that is required, that is provided free in space.

Semiconductors. Turns out here on earth the machines costs hundreds of millions of dollars to etch a wafer because of the use of various technologies to create vacums, control for foreign material, and ensure the micro etches "Stay" and the material "goes". There is a wide discussion, and multiple tests conducted on the ISS that has confirmed this. So, space may be the only way to build next-gen semi conductor tech to get us below 2nm, and a much higher yield, with much cheaper equipment. With the cost of a launch at ~100m on a falcon, the launch would be cheaper than the equipment they are sending up.

ZBLAN fiber optics, growing protein crystals, Electron Beam Physical Vapor Deposition, Regolith refining,

are all done better in space. And they will be cheaper in space, and on the moon and mars. They will be more expensive on earth due to the large gravity well.

[usrbinbash]

> Hydrogen and oxygen can be made from water

Judging by [this][1], good luck trying to find adequate supplies of water on the Moon.

> methane can be made from regolith and water.

Again, good luck with that, because as shown [here][2], the amount of carbon in the lunar soil is, shall we say, not great. And since we are already talking about an immensely energy intensive process here, breaking down rocks in a smelter to get at tiny amounts of Carbon, may not be a very good solution.

So to have a chance at an adequate supply of CO_2 for the Sabbatier Process, you'd have to mine cold-trapped carbon dioxide. Which [may exist][3], or it might not. If it exists, it exists in the coldest regions of the moon, aka. places where you have no access to the only available energy source (Solar). Good luck hauling dry ice across the Moon to the base, especially since it will cease to be a solid the closer the transport comes to the processing plant.

And this process btw. requires HUGE amounts of energy, equipment, machinery and storage infrastructure. [This video][4] gives you a good idea of how difficult making CH_4/LOX fuel with ISRU using the Sabbatier process is ... on Mars, where you can actually pull CO_2 from the thin atmosphere, and likely have more water available.

So in summary:

1. No, we cannot just make the fuel on the Moon

2. Even if we could, it would likely end up being comparatively easier to just ship it there from Earth

3. Even ignoring all that, good luck making the amounts required to keep industrial-scale launches of materials happen

> control for foreign material

If you want to have a real challenge regarding keeping foreign material out, then try manufacturing things in an environment that is filled with hyperstatic, completely dry, microabrasive, pulverized regolith, and having to build clean rooms in an environment with the kind of temperature differentials experienced between the lunar day/night cycle, or worse, in space.

Also, if a clean room fails here on Earth, it's a huge headache for everyone to recover it. If an airlock fails on the Moon, people die, and the production facility gets destroyed by explosive decompression.

> And they will be cheaper in space, and on the moon and mars.

No, they won't, because again: These materials, even if they actually benefited from being produced off-world (and that's a big IF) will only be of any use here on Earth. There won't be any self-sustaining colonies in outer space, or on the Moon, or on Mars. There won't be sprawling industrial sites. We'll be lucky if we can keep a small crew of Astronauts alive on another Planet or the Moon for a few Months until they can get back and start the recovery process after having their bodies wrecked by Microgravity for a prolonged period of time.

So the only market for ANYTHING produced "up there", is "down here", and this, again, is where the prohibitive transportation costs come in and make the whole discussion moot.

[1]: https://en.wikipedia.org/wiki/Lunar_water

[2]: https://en.wikipedia.org/wiki/Lunar_soil#/media/File:Composi...

[3]: https://www.sciencedaily.com/releases/2021/11/211115151010.h...

[4]: https://www.youtube.com/watch?v=Wum8_8sWdeU

[SCM-Enthusiast]

I get the direction that the video was going on... but all it did in my mind was prove that it was completely possible. 5k solarpanels, two full football fields or 17 small nuclear reactors is all that is required for the process? I would have thought it'd be more.

I get what you're saying... it will be hard... for sure... Is it possible in the timeframes being discussed? probably not. Is it an endevor for our generation to embark on? yes. It's the greatest adventure ever written, and yeah... it's gunna suck for all people involved. It's a hostile wasteland.

With that out of the way... I think the video you linked tells the story dishonestly. The deltav required to get from mars, nor to the moon back to the ISS, is no where near refilling a full tank. Without a retro burn, it would require around 1/8th of the deltaV.

Secondly, you can send 10, 20 starships before, or each cycle and spin up. No one is saying that the very first time you send people they will use Insitu 100%. Maybe they bring the hydrogen, or the carbon dioxide and try and get a plant going. Or they can send all the fuel required beforehand. Once they have some kind of more permanant presence, they can slowly ramp up and take a more and more of the process on.

Not all these projects need to be solved at once. With 100T carrying capacity of each starship, all the youtube video convinced me of that it will take around 30-40 starships... which isn't that wild.

I would be more interested in what you think about the more advanced manufacturing, despite all the problems and infrastructure required?

[jandrese]

The only way mining and refining on the moon makes any sense is if you're building stuff to be used on the moon in your lunar colonies, and that's a long way off.

[jandrese]

This sounds completely insane to me. Are people worried that China is going to mine out the moon before the US gets there? You're talking about trillions of tons of material, it won't be the limiting factor in your lifetime. And this assumes that lunar mining/refining is even practical.

[RobotToaster]

Same, but if that kind of paranoia gets us back into space I don't mind it ¯\_(ツ)_/¯

[bryanlarsen]

None of the material on the moon is worth more than the cost of shipping it back to Earth.