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points by Yizahi 3 days ago | 0 comments
Given the current state of the lift industry and price per kilo, it is economically unfeasible to manufacture or mine anything in space if it needs to be transported down or up the gravity well of any planet. Not even chips.
[–] solyin 3 days ago
What if zero g is the best or only place to manufacture something? Varda grows crystals in space to make medicine that works better than when grown in a gravity well.
[–] Yizahi 2 days ago
That is a valid argument but so far I'm not aware of anyone doing the complete calculation of what that could entail and which exact medicine could be cost efficient to manufacture like that.

But if that would be a real market case, then Elon's solution is actually the optimal one, and very similar to the possible approach which more knowledgeable space analysts said for years. Basically it is super pointless for humans now to have big manned space stations for any economical purposes. We should build them of course, but they will be a net loss for centuries. If any space research or space manufacturing would be required by the market, then one-off space missions are the only rational way to do it cheaply. Something like the platform showcased here, or something bigger, like a converted Dragon/Cygnus/etc. ship into a mini lab. Commercial Space Stations is a bunk program, specifically in the word "Commercial".

[–] etiennebausson 2 days ago
I disagree.

Commercial manufacturing in space can be economically viable, as long as most of the components do not come from Earth.

If you build titanium stations in space, but all your titanium come from the moon, the price structure is wildly different. The price of shipping material is the price of building a railgun on the moon.

Absolutely not cheap,but the operating cost afterward is very low. And since the moon is geolocked, you can target any lagrange point with very good precision.

There will still be a need for components coming from earth, but the moon should be able to send all the material for structural parts (titanium), and also solar panels.

[–] rbanffy 2 days ago
> The price of shipping material is the price of building a railgun on the moon.

This would be very unfortunate. Luckily, we only need to build the rail gun (and the mining/refining facilities) once. After that, the cost is marginal.

[–] Yizahi 1 day ago
I wouldn't call a maintenance and ops for a large energy intensive Lunar structure "marginal". The dust is going to be a major pain permanently. Powering the system will be a pain, cooling both railgun and power generation for it will be an incredible feat of engineering. And that's just the initial hurdles of what I suspect would be a thick book list just the problems.

PS: I would also leave it to everyone to evaluate how many seconds would this railgun keep existing until the other superpower will blow it up to pieces, "just in case". Question works the same for any owner and any opponent pairing.

[–] rbanffy 1 day ago
The blowing up part is very valid - humanity will need to grow up before we can make such a thing, but the rest stays - once it’s built, we only need to maintain it, and we can design for low maintenance.
[–] kamaal 2 days ago
>>it is economically unfeasible to manufacture or mine anything in space if it needs to be transported down or up the gravity well of any planet

Hydrolysis can be used to make Hydrogen, so as long you have enough ice. You fill it up with fuel needed to go up again, and send in down with the gravity well with the payload.

[–] jareklupinski 3 days ago
> it is economically unfeasible to manufacture or mine anything in space if it needs to be transported down or up

leave it in space then; massive star ships shouldnt need to come down to planets anyway

[–] IAmBroom 2 days ago
> massive star ships

LOL.

[–] metalman 3 days ago
economicaly unfeasable for you perhaps, but what Elon is offering is a chance to be in the first wave of routine commercial access to microgravity, 1000kg mass and durration of your choice, and if you can achive the materials science objective to make something, that wasn't, possible, and have a market, then it's just manufacturing, and for many business concerns, negative data is worth the same as positive, because it refines where to put there research efforts, which there competition will have to guess at.again 1000kg's , crazy!, makes building the module SO EASY, mass to BURN baby, go! go! go!
[–] oliculipolicula 2 days ago
More of that generous absurdity from you, please. That's your comparative advantage

The following isn't more absurd, in fact opposite, alas. A much better payoff than microgravitated materials research, and further, it makes sense to start NOW

  Evolve bony vertebrates to thrive in microgravity. Use that learning to genetically enhance humans
[–] adrian_b 2 days ago
The time when we will be able to modify vertebrates to thrive in microgravity is much farther in the future than the time when we will be able to build interplanetary ships with artificial gravity generated by rotation.

The former requires some scientific breakthroughs for which it is unpredictable when they will happen.

The latter is an engineering problem with very little unknowns, which is guaranteed to be solvable today if enough money are provided for it.

Until now, the additional costs for rotating ships could be avoided, as long as humans did not go farther away than the Moon.

For an expedition to Mars or even to some more distant celestial body, currently there is no known way that would avoid severe health damage for the humans, without using artificial gravity.

The experiments on the ISS have shown that for mice a gravity of at least 2/3 of that of Earth is required to completely avoid all health problems, while a gravity of at least 1/3 of that of Earth is necessary to avoid the most dangerous health problems.

It is unlikely that humans will prove to be much more resilient than mice.

[–] oliculipolicula 2 days ago
Should start rightaway exactly because it's so faraway. I'm also comparing to all the materials research that are being suggested here, for which specifically microgravity enabled breakthroughs seem ... quite impossible? Including efficiency breakthroughs of the economic variety, btw.

(Yes I agree rotating spaceships are cool/feasible, but what if you are dead set on finding "benefits" of microgravity?)

And out there, you have free radiation for that accelerated evolution..