Why are Space Elevators not a horrible idea, as bad as gunpowder cannons to space?

[sgt_flyer]

1 hour ago, SomeGuy123 said:

I'd say the technical challenge is the magnetics (a maglev railway able to receive something at over a kilometer a second?  Wow. )  and getting enough construction machinery to the Moon and operating it for years to build something this major.

You'd basically need self replicating machinery and a massive industrial base on the Moon itself.

well, if we build either an elevator or a maglev track on the moon, it will be in order to support an already ongoing exploitation of the moon anyway  - and you'll already need some form of industrial processing before shipping those materials. (sending refined materials would be more useful than sending raw ones - especially if the materials are meant for some kind of orbital factory - at least, you could bury radiators in the moon's soil to get rid of industrial process waste heat more easily than you could 'in space) -so you'd have some form of light industry already in place for that.

as for fully self-replicating machines, i'd guess that we would at first keep on making most of the electronics here on earth, while the machines on the moon would focus on making most of the mechanical parts (having to only send the electronics would drastically reduce the payloads we'd have to send to the moon, after sending the first machines able to recreates their own mechanical parts, most likely some sort of 3d printer. once we get enough of those, we'd start making specialised machinery)

still, with the known moon's elemental composition, i'd guess parking asteroid in orbit or at L1 (doubles as a potential elevator counterweight) with an elemental composition to make up for what the moon is lacking (ex, copper / carbon) would be useful.

Edited February 14, 2016 by sgt_flyer

[SomeGuy123]

1 hour ago, sgt_flyer said:

as for fully self-replicating machines, i'd guess that we would at first keep on making most of the electronics here on earth, while the machines on the moon would focus on making most of the mechanical parts (having to only send the electronics would drastically reduce the payloads we'd have to send to the moon, after sending the first machines able to recreates their own mechanical parts, most likely some sort of 3d printer. once we get enough of those, we'd start making specialised machinery)

still, with the known moon's elemental composition, i'd guess parking asteroid in orbit or at L1 (doubles as a potential elevator counterweight) with an elemental composition to make up for what the moon is lacking (ex, copper / carbon) would be useful.

 

Yes, you could make self replicating factories with a far lower tech-base needed if the factories "only" self replicated 90% of themselves and needed 10% of their total bill of materials imported from much larger and advanced factories on Earth.

What is the Moon missing?  If it's a chunk of the earth, originally, it should have a true element mix close to the earth. (but missing the liquids and gasses that are in the atmosphere and oceans since that all sublimated long ago) Nobody has actually dug deep rock core wells at sample points over the entire lunar surface, so the "known" composition is just guesswork.  

Edited February 14, 2016 by SomeGuy123

[peadar1987]

A lot of the earth's mineral deposits are due to volcanic, atmospheric, or fluvial processes, things which are absent or less significant on the moon. You also would have to do some big surveys to find out where all the resources are located. Self replicating machines on the macroscale are very possible, even with today's technology, but they would still require a lot of groundwork and infrastructure.

[SomeGuy123]

36 minutes ago, peadar1987 said:

A lot of the earth's mineral deposits are due to volcanic, atmospheric, or fluvial processes, things which are absent or less significant on the moon. You also would have to do some big surveys to find out where all the resources are located. Self replicating machines on the macroscale are very possible, even with today's technology, but they would still require a lot of groundwork and infrastructure.

Ah.  Fair enough.  I just didn't see how if the Moon was a big molten globule of "earth stuff" once, how it wouldn't end up roughly having the same amount of copper, distributed somewhere, that the earth does, as a proportion of the Moon's mass.  Ditto everything else but light elements that would leak to space.

[peadar1987]

31 minutes ago, SomeGuy123 said:

Ah.  Fair enough.  I just didn't see how if the Moon was a big molten globule of "earth stuff" once, how it wouldn't end up roughly having the same amount of copper, distributed somewhere, that the earth does, as a proportion of the Moon's mass.  Ditto everything else but light elements that would leak to space.

Yeah, it will have roughly the same composition, but as I understand it, many things like copper deposits are caused by water leaching small concentrations out of the rock, and depositing it somewhere where it collects. Someone with a background in geology or mining please feel free to correct me on this though.

[Exploro]

13 hours ago, peadar1987 said:

You also would have to do some big surveys to find out where all the resources are located.

I think the Clementine and LRO missions did just that.

[fredinno]

On 2/14/2016 at 8:48 PM, SomeGuy123 said:

 

Yes, you could make self replicating factories with a far lower tech-base needed if the factories "only" self replicated 90% of themselves and needed 10% of their total bill of materials imported from much larger and advanced factories on Earth.

What is the Moon missing?  If it's a chunk of the earth, originally, it should have a true element mix close to the earth. (but missing the liquids and gasses that are in the atmosphere and oceans since that all sublimated long ago) Nobody has actually dug deep rock core wells at sample points over the entire lunar surface, so the "known" composition is just guesswork.  

The Moon is missing a lot of the Earth's core, and is mainly composed of the mantle and crust sucked out. Thus, it is lacking in metals (though not really a huge problem due to asteroid impacts) and volatiles (a problem)

7 hours ago, Exploro said:

I think the Clementine and LRO missions did just that.

Those were VERY basic compared to the stuff needed for mining.

[sgt_flyer]

guess that could be a good interrogation before anyone thinks of exploiting the moon  - based on what's remaining of 'easily' extractable resources on earth, and known moon resources - outside of He-3, is there some resources that could soon become interesting enough on the moon that it would become cheaper to go mine it there rather than extracting it on earth ? (after all, once easily avaible resources become depleted, trying to get those from less accessible deposits is going to drive extraction costs up)

 

once the overall costs tips in favor of the moon for any resource, guess we would see things hapenning

[magnemoe]

25 minutes ago, sgt_flyer said:

guess that could be a good interrogation before anyone thinks of exploiting the moon  - based on what's remaining of 'easily' extractable resources on earth, and known moon resources - outside of He-3, is there some resources that could soon become interesting enough on the moon that it would become cheaper to go mine it there rather than extracting it on earth ? (after all, once easily avaible resources become depleted, trying to get those from less accessible deposits is going to drive extraction costs up)

 

once the overall costs tips in favor of the moon for any resource, guess we would see things hapenning

Main focus on materials from Moon is for use in space. Asteroids are probably better for the valuable stuff. Vater is an primary, also aluminum and silisium is interesting

[sgt_flyer]

@magnemoe

mmh. wouldn't 'industrial' space factories (and any logistic infrastructure like space elevators) 'for' space be made in order to support lower cost expansion of activities placed before ? there are currently not really customers in space to buy most of the stuff we could make in orbit - (current satellites, outside of propellants / batteries, are mostly made of electronics - which need high tech factories.) - it would be a huge leap of faith for any buisness to devellop such orbital factories, in the hopes there will be someone to buy your products. - while if it's done in support of existing mining operations, it makes more sense.

guess that's one damn vicious circle - moon / asteroid resource exploitation costs would be prohibitive without a supporting orbital industry and logistics - which in turn would be useless if built 'before' the resource exploitation that would need such services exists - we would basically need an entity with enough wealth and power to set up both systems at the same time to kickstart such thing (that, or we need some cheap acess to space - which would negate most of the usefulness of orbital factories in the first place - leaving only mostly resource exploitation)

[KerikBalm]

9 hours ago, fredinno said:

The Moon is missing a lot of the Earth's core, and is mainly composed of the mantle and crust sucked out. Thus, it is lacking in metals (though not really a huge problem due to asteroid impacts) and volatiles (a problem)

Those were VERY basic compared to the stuff needed for mining.

Well, since we don't mine our core, and we depend on the stuff that mantle plumes bring to the surface... and the moon would be formed from the same mantle, its bulk composition should be similar to earth's crust minus the volatiles.

The problem is in the processes that concentrate materials rendering it feasible to extract them.

You could in theory mine gold from sea water, or just about any element you want in there... but the concentration is so low... its not like sifting a river for gold nuggets (as one could do before the gold was mostly all mined out during the gold rush).

Likewise... the elements are there on the moon, but they aren't easy to access... I also wonder if some of them sank into the interior, and since therewas less internal heating, there was little mixing when the moon solidified, leaving the crust even more depleted of heavier elements than the earth's crust?

Or maybe it was all well mixed in the impact, and then it rapidly solidified... but if you want an element... and its *everywhere* but at only a few parts per million, then its hard to extract... like getting gold from sea water.

[fredinno]

On February 15, 2016 at 5:27 AM, sgt_flyer said:

guess that could be a good interrogation before anyone thinks of exploiting the moon  - based on what's remaining of 'easily' extractable resources on earth, and known moon resources - outside of He-3, is there some resources that could soon become interesting enough on the moon that it would become cheaper to go mine it there rather than extracting it on earth ? (after all, once easily avaible resources become depleted, trying to get those from less accessible deposits is going to drive extraction costs up)

 

once the overall costs tips in favor of the moon for any resource, guess we would see things hapenning

 

On February 15, 2016 at 9:34 AM, KerikBalm said:

Well, since we don't mine our core, and we depend on the stuff that mantle plumes bring to the surface... and the moon would be formed from the same mantle, its bulk composition should be similar to earth's crust minus the volatiles.

The problem is in the processes that concentrate materials rendering it feasible to extract them.

You could in theory mine gold from sea water, or just about any element you want in there... but the concentration is so low... its not like sifting a river for gold nuggets (as one could do before the gold was mostly all mined out during the gold rush).

Likewise... the elements are there on the moon, but they aren't easy to access... I also wonder if some of them sank into the interior, and since therewas less internal heating, there was little mixing when the moon solidified, leaving the crust even more depleted of heavier elements than the earth's crust?

Or maybe it was all well mixed in the impact, and then it rapidly solidified... but if you want an element... and its *everywhere* but at only a few parts per million, then its hard to extract... like getting gold from sea water.

Asteroid impacts make Luna a good place for precious minerals- though I would only expect mining to be surface, with little underground mining.

[Rakaydos]

On 2/15/2016 at 8:29 AM, sgt_flyer said:

@magnemoe

guess that's one damn vicious circle - moon / asteroid resource exploitation costs would be prohibitive without a supporting orbital industry and logistics - which in turn would be useless if built 'before' the resource exploitation that would need such services exists - we would basically need an entity with enough wealth and power to set up both systems at the same time to kickstart such thing (that, or we need some cheap acess to space - which would negate most of the usefulness of orbital factories in the first place - leaving only mostly resource exploitation)

An interesting conundrum. But what happens if we assume Elon Musk makes a leap of faith, providing a basic and expanding base on mars. How can orbital infrastructure reduce his costs AFTER he gets started?

[sgt_flyer]

@Rakaydos hehe that's the heart of the problem - setting up automated orbital infrastructures (maybe using things like an evolved version of the robonaut2 to carry out maintenance of the automated systems - those would be piloted by groundstaff, so you don't need to send up workers)

  with these facilities, you'll only need to send up electronics, which would make those spacecrafts much cheaper (as you don't need to send up heavy stuff) - which would drastically reduce the amounts of rocket launches needed... in turn serverly increasing the launch costs per rocket (so basically, you'd have to set up cheap space access first, only to discard it afterwards - especially if you end up creating a space elevator thanks to those orbital facilities) - again, vicious circle. to overcome it, you would need an entity willing to do all those steps by itself to set up this specific endgoal. (i wonder how launch providers would respond if another company would hire them to put into orbit those facilities - at first increasing their workload, but putting them out of satellite launch business afterwards ?

 

Edited February 16, 2016 by sgt_flyer

[fredinno]

1 hour ago, llanthas said:

Still reading through 6 pages of this.. but regarding construction - Why is it always assumed that we would do it from the ground up, with a spooling rocket??   That would never work, ever. 

The simpler solution would be to launch the entire spool to its geo-stationary position, then fire a very tiny thruster out of the spool, attached to one end of it.  Just enough to get below geo-stationary orbit, and let the end fall to earth...

I think we already established this...

[MatttheCzar]

It'll only work well on the moon.  Kevlar-type materials could make it right now.