Off-planet manufacturing (split from SpaceX)

[Elthy]

48 minutes ago, kerbiloid said:

They should use the additive technologies more actively.

They anyway need this for Mars. No rolled steel can be bought there.

1. We dont know how if they arent allready using addidive manufactoring for parts of the engine

2. Additive manufacturing makes only sense in very specific cases: Very complex geometry, very small lot numbers. While a rocket engine usualy has both im not sure about the raptor, as its supposed to be mass-produced.

3. Additive manufacturing is extremly complicated, requiring not only high precision hardware but also metal powder with tightly controlled specs, thats quite hard to manufacture even on earth. It will be way, way easier to make rolled steel on mars.

Why do people often see additive manufacturing as a magic bullet to make stuff faster/cheaper when its exactly the opposite in almost all cases?

[kerbiloid]

12 minutes ago, Elthy said:

Why do people often see additive manufacturing as a magic bullet to make stuff faster/cheaper when its exactly the opposite in almost all cases?

Because it doesn't need people. It depends only on amount of machinery and power.

[Elthy]

You have never worked with additive manufacturing, do you? Its way more labor intensive than milling or molding. Automating would be  possible (although extremly hard), but only if you produce so much that its way easier to use more traditional methods, so never worth it.

[kerbiloid]

21 minutes ago, Elthy said:

Its way more labor intensive than milling or molding.

It can be automated better than any other kind of metal processing.

Also, it's the only sustainable metal parts manufacturing technology on other planets.

Because you can't have a full-chain industry there. Lack of resources, lack of scale.

When your metal is a powder from the evaporated local minerals, it's a ready-to-use material for 3d printing.
And you don't have sheet and wire to buy.

So, by having the 3d-printed Falcons and Starship here, you already have them being built right there.
So, you can colonize Mars many times faster.

Edited May 30, 2021 by kerbiloid

[Elthy]

28 minutes ago, kerbiloid said:

It can be automated better than any other kind of metal processing.

Also, it's the only sustainable metal parts manufacturing technology on other planets.

Because you can't have a full-chain industry there. Lack of resources, lack of scale.

When your metal is a powder from the evaporated local minerals, it's a ready-to-use material for 3d printing.
And you don't have sheet and wire to buy.

So, by having the 3d-printed Falcons and Starship here, you already have them being built right there.
So, you can colonize Mars many times faster.

Where do you get that kind of information? If you know how to make the required powders without full-chain industries you could make a lot of money with that on earth, similary with automatition.

[YNM]

54 minutes ago, kerbiloid said:

It can be automated better than any other kind of metal processing.

Correction : It's only possible through automation. You'll never 3D print anything by moving the nozzle with your own hand manually.

And that shows it's pretty complicated as dumb humans can't do it.

Edited May 30, 2021 by YNM

[Elthy]

1 minute ago, YNM said:

You'll never 3D print anything by moving the nozzle with your own hand manually.

https://the3doodler.com/

But the difficulty in automatition doest come form the process itself, but from the handling of the powder and quality assurance. Those metall-printers are a poodle to clean and high maintenance, the "finished" parts need lots of post processing including removing all the stuck dust and it would take a good KI to automate that as its almost comparable to digging out a valuable artifact as an archeologist. Even tiny variations in the process can screw up the result as you are heat-treating while manufacturing, making quality assurance quite difficult.

[kerbiloid]

10 minutes ago, Elthy said:

Where do you get that kind of information? If you know how to make the required powders without full-chain industries

Do you want me to list all phases of the metals processing from the ores to rolled sheets?
I'm afraid, the description will take several pages,

And you can't have 90% of that on Mars. No coal, first of all. No customers to have the specialized factories producing hundreds of thousands types of details.

All you have is the ore and a limited need in details of various types.

[YNM]

12 minutes ago, Elthy said:

But the difficulty in automation doesn't come form the process itself, but from the handling of the powder and quality assurance.

I'm actually kind of wondering if space environment would be an advantage in this regard. No organic contamination, to start with. Regolith is just metal oxide, some aren't even fully oxidized that the smell they have when returning from lunar EVA was from the dust oxidizing further.

Although to be fair the metals are mixed up, and I'm not sure how would one separate them into separate elements (silicon, aluminum, iron etc) without chemical process. Not really well-versed in metallurgy.

Edited May 30, 2021 by YNM

[kerbiloid]

You can't extract the metals chemically there, only physically.
So, any piece of metal comes from the cooled dust.

This means that any steel sheet on Mars should come from the metal dust, No rolled slabs,like on the Earth.

Of course, you can 3d-print the slabs and roll them, lol!

***

And next you need various cutting and rolling machines to make the rolled metal self-sustained.

But you don;t have 1000 customers to buy all sort of your goods by containers.

So, you will either have a whole machine for every 100 screws and nuts of different kinds, or you should skip the slabbing and rolling, and 3d print them by the same additive machine.

On the Earth, where you just cast the chemically reduced metals, the 3d is expensive.

On Mars its alternatives are even more expensive.

Edited May 30, 2021 by kerbiloid

[wumpus]

5 hours ago, kerbiloid said:

You can't extract the metals chemically there, only physically.
So, any piece of metal comes from the cooled dust.

This means that any steel sheet on Mars should come from the metal dust, No rolled slabs,like on the Earth.

Of course, you can 3d-print the slabs and roll them, lol!

***

And next you need various cutting and rolling machines to make the rolled metal self-sustained.

But you don;t have 1000 customers to buy all sort of your goods by containers.

So, you will either have a whole machine for every 100 screws and nuts of different kinds, or you should skip the slabbing and rolling, and 3d print them by the same additive machine.

On the Earth, where you just cast the chemically reduced metals, the 3d is expensive.

On Mars its alternatives are even more expensive.

If you want metals, why don't you grab them from the asteroid belt?  And why can't you simply smelt something on Mars?  If a solar furnace won't work, try a nuclear one (you'll probably want it for power anyway).  Smelting on the belt is much more iffy, although perhaps any low quality rock can be used as an open cycle coolant.

[JoeSchmuckatelli]

41 minutes ago, wumpus said:

If you want metals, why don't you grab them from the asteroid belt?  And why can't you simply smelt something on Mars?  If a solar furnace won't work, try a nuclear one (you'll probably want it for power anyway).  Smelting on the belt is much more iffy, although perhaps any low quality rock can be used as an open cycle coolant.

Apparently smelting requires quite a bit of O2 as well as heat.  Started looking into this (cursorily) after that post - and there's some pretty interesting features to all of this of which I was unaware: Caveman to Chemist Projects: Metals (cavemanchemistry.com)

Roasting was something else I learned about: Smelting and Roasting Ores to recover gold, silver and other metals (nevada-outback-gems.com)

(I used to think all you needed was heat and gravity / centrifuge to separate ores from slag)

Getting at the rarer materials really does require a lot of chemistry as @kerbiloid wrote - way more than one might think

Edited May 30, 2021 by JoeSchmuckatelli

[YNM]

11 minutes ago, JoeSchmuckatelli said:

Apparently smelting requires quite a bit of O2 as well as heat.

The initial O2 is mostly used to make sure anything else other than oxides are converted into one.

The real change is from the coal/charcoal. It basically transfers the oxides into the carbon from the metal element.

Finally if you want to reduce the carbon content you just blow it with more oxygen while very hot.

Edited May 30, 2021 by YNM

[tater]

The Moon is 43% Oxygen (from memory, but something like that).

[YNM]

2 minutes ago, tater said:

43% Oxygen

Yeah but in the oxides themselves... You basically need to remove it from there, using some reducing agent. That's what is normally hard to find.

Edited May 30, 2021 by YNM

[kerbiloid]

1 hour ago, wumpus said:

If you want metals, why don't you grab them from the asteroid belt? 

Because it's on Mars. It's far from the asteroid belt, and I've never heard SpX is going to go there.

1 hour ago, wumpus said:

  And why can't you simply smelt something on Mars? 

Because on the Earth all metallurgy is totally based on coal. Either to chemically reduce the metal (Fe), or as enormous amount of expendable graphite electrodes (Al).

As nothing but Earth ever had algae, so the coal is available only here. Other planets can use only plasma ovens, ionizing the minerals, blowing helium or nitrogen through it, and collectiung the particles.
So they create thin metal dust as primary form of the metal. Which is exactly what the 3d printers use.  

22 minutes ago, tater said:

The Moon is 43% Oxygen (from memory, but something like that).

It's weird to think that a stone contains twice more oxygen than air.

Edited May 30, 2021 by kerbiloid

[Beccab]

48 minutes ago, kerbiloid said:

Because it's on Mars. It's far from the asteroid belt, and I've never heard SpX is going to go there

Tbh i'm not sure i have ever heard spacex talk about building starship on mars either

[cubinator]

59 minutes ago, kerbiloid said:

on Mars. It's far from the asteroid belt, and I've never heard SpX is going to go there.

There are official renders of ITS/Starship standing on Europa, and around Saturn. Those are simply more photogenic destinations, but the Asteroid Belt is a likely target after Mars.

[Beccab]

Just now, cubinator said:

There are official renders of ITS/Starship standing on Europa, and around Saturn. Those are simply more photogenic destinations, but the Asteroid Belt is a likely target after Mars.

I'd take those with a grain of salt, imo they are the Starship equivalent of Boeing's pdf about all the exciting possibilities SLS has. If it will ever happen, it is still very far from now, and even long after a mars landing. Deep space starship is indeed possible but, being unrelated to mars development, also less of a priority (lunar starship is the exception as it is wanted by NASA and easier than mars)

[kerbiloid]

17 minutes ago, Beccab said:

Tbh i'm not sure i have ever heard spacex talk about building starship on mars either

SpaceX is going to colonize Mars.

This means a lot of construction.

5 minutes ago, cubinator said:

There are official renders of ITS/Starship standing on Europa, and around Saturn.

There is no even a single word how are they going to survive so long.
Starship is just a chemical rocket, while even asteroids require at least gaseous nuke.

[cubinator]

Just now, Beccab said:

I'd take those with a grain of salt, imo they are the Starship equivalent of Boeing's pdf about all the exciting possibilities SLS has. If it will ever happen, it is still very far from now, and even long after a mars landing. Deep space starship is indeed possible but, being unrelated to mars development, also less of a priority (lunar starship is the exception as it is wanted by NASA and easier than mars)

Indeed, I wouldn't want to spend years in a Starship going to the outer solar system. But exploring the asteroid belt in some capacity, at least just with probes, seems reasonable.

[kerbiloid]

Just now, cubinator said:

But exploring the asteroid belt in some capacity, at least just with probes, seems reasonable.

No. It takes years to get there. No artificial gravity, thin walls, etc.

Mars is the fartherst place one can get alive on chemical engines.

[cubinator]

Just now, kerbiloid said:

No. It takes years to get there. No artificial gravity, thin walls, etc.

Mars is the fartherst place one can get alive on chemical engines.

That's why I said probes.

[kerbiloid]

Just now, cubinator said:

That's why I said probes.

The probes do that for decades, and they need ion engines rather than Starship.

[Beccab]

7 minutes ago, kerbiloid said:

SpaceX is going to colonize Mars.

This means a lot of construction.

Sure, but again, why should they build starship there