Lunar Space Elevator

Dook · 2005-10-17 19:19:23

I was reading up on space elevator concept and found that a space elevator on the moon could be made with current materials.

It would have to be very long, twice as long as one on the earth but this would solve the problem of delivering PGM's mined from the lunar surface to space. We wouldn't need to make rocket fuel on the moon.

We would then have to capture the PGM pod (or whatever) in space and bring it down in the CEV, a capsule, or whatever.

The operation might even be completely automated.

http://en.wikipedia.org/wiki/Space_elevator

GCNRevenger · 2005-10-17 19:34:22

An issue or three needs to be sorted out first:

The station at the end of the cable will probobly be at Lagrange-1 point, which is only sort of stable. This probobly means that the station would need some ability to maneuver, which means a steady supply of ion drive fuel from Earth or a steady supply of LOX from the Moon.

Another issue is how to power the climbers. Given the much longer distance, beamed power might be a little more difficult. You would have the advantage of no atmosphere to interfere however.

But yeah, ultimatly if we really want to exploit the Moon, this would be the way to do it, but such a setup would still cost quite a bit.

noosfractal · 2005-10-17 20:33:37

Another issue is how to power the climbers.

Apparently, you can get 100 km/hr ascent just with solar. And 2000 kg can be on the cable at any one time. Here is an Oct 2004 paper ...

http://www.star-tech-inc.com/papers/lse … _Final.pdf

The diagram has two cables - one from the equator and one from the pole. I read somewhere that NASA gave these guys money for an in depth study.

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SpaceNut · 2005-10-20 09:46:32

Another problem to overcome is powering the climber. This article ends with the new Beam Power Challenge.

Space Geeks Seek Wireless Power

Space elevators need power beaming," said Brant Sponberg, manager of NASA's Centennial Challenges project. "They can't carry an extension cord all the way down to the ground."
As a result, NASA has created the 2005 "Beam Power Challenge" to award $50,000 to the team whose climbing bot can lift the most mass in three minutes by most efficiently converting beam power into electricity. Second and third place will receive $20,000 and $10,000, respectively.
At this year’s Oct. 21 competition, all teams will receive power from the same photonic source: a 10-kilowatt Xenon searchlight. But next year’s competition will allow each team to also build their own beam-power device, which could use photons, lasers or microwaves. Sponberg said the purse for the 2006 competition will be $150,000 ($100,000, $40,000 and $10,000 to the three best teams).
But Sponberg also pointed out that "NASA has no plans to build a space elevator in the near future," which means that such power-beaming innovations may not be applied for years, if ever.

noosfractal · 2005-10-20 15:24:59

Another problem to overcome is powering the climber.

The climbers for Earth's space elevator probably need laser beamed power (although there may be some other clever way to power them), but it seems that the lunar climbers can achieve 100 km/hr just with solar panels because of the reduced gravitational field.

I wonder if the Terran climbers can be powered just with solar after a certain point? Gravity drops to below 1% of the surface value at about the 14000 km mark.

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reddragon · 2005-10-20 19:06:40

Although a lunar elevator may be possible with today's technologies, it may actually be easier just to develop the nanotube technology we need to build an Earth-based elevator, and it would certainly be more beneficial to the world. Indeed, once we have an elevator from Earth it will be easier to get the supplies and people we need to build one on the moon up there.

I also wonder if it is really worthwhile to mine lunar PGMs when they can be had in much higher concentrations directly from the asteroids.

There are certainly reasons to go to the moon and in time to build a space elevator there, but I don't really think it should be a top priority.

Commodore · 2005-10-20 19:46:01

Depends on how hard it is to either mine the platinum on the asteroids, or to move the asteroid.

A mass driver might be more ecnomical anyway, but we will still need something to catch unguided material.

SpaceNut · 2006-02-09 11:53:11

Nasa is continuing with its efforts with Centennial Challenges

Some of the proposed contest to be run...

Fuel Depot Demonstration Challenge
Human Lunar All-Terrain Vehicle Challenge
Low-Cost Space Pressure Suit Challenge
Lunar Night Power Source Challenge
Micro Reentry Vehicle Challenge
Station-Keeping Solar Sail Challenge

Some of these are needed for the visions immediate use while others are for the far off future and for colonization.

GCNRevenger · 2006-02-09 13:44:04

Although a lunar elevator may be possible with today's technologies, it may actually be easier just to develop the nanotube technology we need to build an Earth-based elevator, and it would certainly be more beneficial to the world. Indeed, once we have an elevator from Earth it will be easier to get the supplies and people we need to build one on the moon up there.
I also wonder if it is really worthwhile to mine lunar PGMs when they can be had in much higher concentrations directly from the asteroids.
There are certainly reasons to go to the moon and in time to build a space elevator there, but I don't really think it should be a top priority.

Mining asteroids, due to the lack of gravity and that essentially all of them have fairly fast multi-axis spins, and it takes a really long time to get to and from them, basically makes them so hard to mine that going down to the Moon and back, where there is a fairly plentiful supply of oxygen, is really the best choice.

publiusr · 2006-02-09 14:51:50

Asteroid Hunt:
http://www.space.com/businesstechnology … tarrs.html
Asteroid mining
http://www.space.com/adastra/060209_adastra_mining.html
Running out of metal.
http://www.livescience.com/othernews/06 … etals.html

MikkelR · 2006-02-18 05:20:11

This might be worth a look

Space-elevator tether climbs a mile high
http://www.newscientistspace.com/article/dn8725.html

dicktice · 2006-02-18 14:39:00

Having been away from these forums for some time, I'm pleased to find that GCNR is still pontificating negatively about just about anything slightly uneconomic in the space transportation line--in the present instance, about asteroid mining. Might I suggest he read [publiusr's] suggested item headed: "Asteroid mining," before reacting to my criticism (in no way offered as a personal attack) before offering the inevitable rejoinder?

Virtually all the points made by the author of the article, Australian Mark Sonter, coincide with my admittedly optimistic belief in the potential of the until-now pretty much ignored asteroids with orbits entirely inside that of Earth.

In the meantime, re. GCNR's objections to asteroid mining in general. He wrote:

"... due to the lack of gravity and that essentially all of them have fairly fast multi-axis spins ..." That needs some clearification. How can an asteroid have more than a single spin-axis? Once the axis has been determined, I imagine accessibility could be maintained to the asteroid via tether from a human prospector ship (eventually the remote presence refining facility). And by hollowing-out and mining the ore-body (having initially tunnelled to the centre of mass) the spin itself could provide a modicum of "gravity" to facilite any ore treatment prior to delivering the product (again via the spin-axis) for weightless further processing, refining, etc.

"... it takes a really long time to get to and from them, basically makes them so hard to mine that going down to the Moon and back ... is really the best choice." The article reiterates what I have read elsewhere, that "... [NEAs] are energetically more accessible (easier to get to) than the Moon (i.e. under 6 kmv/s from LEO), and a substantial minority of these have return-to-Earth traansfer orbit injection delta-V's of only 1 to 2 km/s." The time element obviously ceases to be an objection, once the remote presence processing is up and running.

The article notes, almost in passing, my favorite answer to the problem of getting about in cis-Lunar space, ie: "Water is an obvious first, and key, potential product from asteroid mines, as it could be used for return trip propulsion via steam rocket."

GCNRevenger · 2006-02-18 17:17:18

"How can an asteroid have more than a single spin-axis?"

What? You are not making any sense. All objects have three axies, and any object can spin around more then one of them at once. For instance, a rocket can be rolling around its long axis as well as pitching/yawing simultainiously; Shuttle does it every time it flies.

Virtually all asteroids spin, essentially none of them are perfectly still rotationally. Anyway, the problem is that if an asteroid spins in one axis, it will be very hard to land reliably on any spot on the rock except at where the spin axis intersects the surface. At these "poles," the ground is only turning very slowly. Now, if you have more then one axis of spin however, there is no slow-moving point anywhere on the surface. Hence, no place to land reliably. The chances that you are going to find a rock with close to zero spin or even single-axis spin are remote given gravitational perturbation.

No landing, no mining... it gets better, because the gravity is so weak your tether would have no "anchor" orbit, so you can't use a tether at all. Since there is no stable point on the surface, you can't use a tether either anyway, since there would be no equivilent to "geostationary" orbit around the rock at any distance or stationary point on the rock to attach it to.

You also aren't going to be "hollowing out" an object several miles in size made of loosely packed rock (which will collapse to fill any holes) or solid metalic "cast" iron (would take decades to tunnel,) and the spin would have to be REALLY fast to give you any appreciable gravity-like effect. Since there is some gravity on most rocks, the gravitational field must be stronger then the centrifugal force anyway, so you wouldn't have any "artifical" gravity. Oh, and due to the multi-axis spin, this effect would not be in a uniform direction either.

Second issue, distance: I know full well that it takes a relativly small delta-V to get to/from a rock from Cis-Lunar space, my issue is that there is no possible way you are going to make a totally automated remote-control mining operation. Isn't possible. Can't be done, the Moon is around 2-3 light seconds, but thats still too long... You have got to have humans on site to operate/repair the machinery. Here is where the distance advantage gives the Moon an edge, that you don't have to spend months soaking up radiation and losing bone/muscle mass in transit to a rock, lose even more when you get there, and have to ride back another several months in a fairly large and fuel-hungry ship.

The Moon? A three-day hop in a little shuttle. The fuel/supply savings, improved safety, and economies of scale (can use same vehicle more often) of not needing a big ship match the increased delta needed for a Earth/Moon transit with Lunar liquid oxygen. Another issue, how does working in near zero-G on an asteroid reduce how long a given miner's "shift" is? Combine this with the transit time, and Lunar miners can stay "on the job" much much longer.

Furthermore, you are not going to be hauling raw ore back to Earth from any body. Its just stupid to try and lug back hundreds of kilos or a tonne of ore to squeeze out a gram of precious metals, so the ore itself will have to be processed on site. How are you going smelt the asteroid with no gravity? Even if you can, it is going to be so hard that it can't possibly compare to a Lunar refinery, which will be easy to build since everything doesn't have to be constructed in near-zero gravity.

And steam rockets? Please, the specific impulse is terrible, and in order to have all this space mining adventure, we are going to have (I said have and I mean have) to have a true, real, "this time we aren't kidding" RLV. Or a space elevator if they're possible... In either event, the cost to bring up raw fuel from Earth will crush the economics of an asteroid water mine.

And a point that I used to rain on Bill's parade and Robert failed to come up with a workable solution is, how do you dig on the surface of a rock that doesn't have signifigant gravity? Drills, digging machines, etc have to have a down force so they can cut into the surface, which on Earth is furnished by our high gravity field. You would probobly have enough on the Moon, particularly given that many asteroid fragments will be small enough to wrap around.

On an asteroid though? Big, flat, and no gravity. Drill pilot holes for cables to hold yourself down on? Uh huh... how are you going to drill the pilot holes without gravity? You might not be able to dig much on "loose rocky" asteroids at all, on the account that pits you dig will collapse and bury your mining site when the rock rearranges its shape. I'm also interested to know how you are going to cut solid iron out of the flat ground with any efficiency.

Edit: Oh, and one more thing, a mining site will probobly bennefit alot from solar power, which the Moon has solid for 1-2 weeks with only periodic array repositioning, while an asteroid with a rotational period of hours will only have light for minutes and need constant array repositioning.

Josh Cryer · 2006-02-18 17:50:25

Hi dicktice! GREAT to see you around! Brought a smile to my face.

For getting stuff off of the moon, I imagine a rail gun would be more economical and easier to operate than a space elevator. That doesn't solve the problem of landing stuff on the moon, though.

Grypd · 2006-02-19 08:51:16

I suppose one way to grab an asteroid is to belt yourself to it by tethers/nets that go around then can be pulled and tightened so bringing your machinery into contact. With this and hopefully an effective steam rocket we can slow the spin of the asteroid. And since we will find it particularily difficult to mine in space can we not direct it to a better orbit for us to mine it.

In this case instead of breaking the ore and refining the metal out why not use a lunar elevator to transport the ore down and then use the Moons gravity to refine with the finished products sent back up an elevator. We wont have to do this with liguids and volatiles as they can be heated out and pure metal asteroids with an asteroid in a stable state easily can be cut using focused sunlight .

Still a lot easier to find an asteroid impact on the Moon and refining it there.

GCNRevenger · 2006-02-19 11:38:10

You want to wrap an asteroid several miles in diameter with cables, strong enough to provide the down force to efficiently cut solid rock or cast iron?

And you want to zero out the rotational inertia of a solid body that weighs millions of tonnes with whimpy, inefficient rocket engines? The laws of thermodynamics still apply, and the Uranium in a hypothetical steam rocket just doesn't have the kind of energy needed to do such a thing.

And no, no its not going to be easy to put an object in Lunar orbit, not easy at all. Even if you did, what good would it do? You have to put the thing in Lagrange orbit to connect to an elevator, where gravity can't "catch" your rock passively I bet.

Even then, no, absolutely not is it any easier to move tens of thousands of tonnes of ore down the elevator just to eke out one load worth of precious metal.

There are plenty of smaller, manageable bits of impacted asteroids on the Lunar surface; why oh why is it so hard to believe that mining and refining them there is inherintly and overwhelmingly superior to asteroid mining?

dicktice · 2006-02-19 12:32:15

Grypd: Anchoring machinery to surfaces using techniques gained from Earth megaprojects plus ingenuity that engineers thrive on, is what we humans do!
Steam rockets powered by solar heat would be capable of any amount of thrust on demand, by means of mechanical light-shutter control via remote presence NOT from Earth, but in realtime from nearby co-orbiting spacecraft at first, and later by unmanned adaptive automatic robotic control station(s). Ore smelting using solar heated and/or thermoelectric furnaces, to reduce mass transported via steam rocket thrusters to Near-Earth orbit destinations.
Lunar space elevator concept escapes me, if what is meant has to be synchronous with the Moon's rotation. To me, the material mined from NEA's would be used in weightless space to construct and maintain space habitats, spacecraft and more refining facilities.
Impacting asteroids whole or in part intentionally should be forbidden by space law, since the impact residues can only lead to additional hazards to Cis-lunar space travel. Impacting the Moon, ditto, once Lunar settlement begins.
It follows that space weapons of attack and defense involving kinetic impact weapons (eg. "smart pebbles") should be outlawed for the same reason.

GCNRevenger · 2006-02-19 13:00:30

"Anchoring machinery to surfaces using techniques gained from Earth megaprojects plus ingenuity that engineers thrive on, is what we humans do!"

*Bzzzz*
-This isn't Earth, its a rapidly spinning mountain millions of miles away with nearly zero gravity, which will either collapse or be nearly impossible to cut with traditional means.

-Human ingenuity ingenshmuity, how are you going to drill/cut/dig into the thing without gravity?

"Steam rockets powered by solar heat would be capable of any amount of thrust on demand"

*Bzzzz*
-No they aren't, and their Isp is even worse then nuclear/water steam rockets. A gigantic mirror will be impractical to handle on/near a rock anyway, thanks to the gravity (bending your mirror) or the spinning (impossible to orient tward the sun).

-Where are you going to get all the water to power such an inefficient engine? Dig it up off the asteroid's surface? You can't even land easily much less dig the thousands of tonnes of ice you would need for such an operation. Then you have to grind, melt, filter, and prevent it from freezing too.

"Impacting asteroids whole or in part intentionally should be forbidden by space law, since the impact residues can only lead to additional hazards to Cis-lunar space trave"

No need to. Plenty of rocks have already impacted the Moon, and are just sitting there waiting for us.

And putting up the human crews in a nearby space habitat doesn't fix the problems associated with crew exchange economies either.

Grypd · 2006-02-19 13:35:11

You want to wrap an asteroid several miles in diameter with cables, strong enough to provide the down force to efficiently cut solid rock or cast iron?

Did I mention cutting rock with these cables no I mentioned grappling them. All they have to do is ensure that we can put machinery close enough to the surface and locate above a spot that our machinery can put a hole that we can then drill into to provide a secure means to operate on the asteroid.

We know that the majority of asteroids are in the 10 meters to 100km range though well over half remain undiscovered. If we search for asteroids of the size between 10 to 250 metres size we should be able to deal with these and our "inefecient" rocket engines with in a reasonable time frame could stabilize there spins. There is other options like shading areas from the sun so that sunlight will slow rotation and also use burst of focused sunlight aimed to slow an asteroids rotation by causing out gasing

Also one of the most important for us is the asteroids that are Ex comets as they should have a very high supply of volatiles. These will tend to be some of the largest of asteroids and as such are unlikely to be a good option to try to slow there spin. But if we are anchored to them then we can use heat to boil out and collect the volatiles and this then can be sent to where we can use it.

And you want to zero out the rotational inertia of a solid body that weighs millions of tonnes with whimpy, inefficient rocket engines? The laws of thermodynamics still apply, and the Uranium in a hypothetical steam rocket just doesn't have the kind of energy needed to do such a thing.

So, dont try to go for those super sized pieces of rock there is plenty of other smaller sized asteroids that we can deal with. There is expected to be tens of thousands of them.

And no, no its not going to be easy to put an object in Lunar orbit, not easy at all. Even if you did, what good would it do? You have to put the thing in Lagrange orbit to connect to an elevator, where gravity can't "catch" your rock passively I bet.

Still it is an option and then there is the possibility of mass driver tugs catching the rocks that come closer to us and then being able to stear the rocks to where we want them. Also the material we send down an elevator will help us by gaining that energy to send up a cargo.

Even then, no, absolutely not is it any easier to move tens of thousands of tonnes of ore down the elevator just to eke out one load worth of precious metal.
There are plenty of smaller, manageable bits of impacted asteroids on the Lunar surface; why oh why is it so hard to believe that mining and refining them there is inherintly and overwhelmingly superior to asteroid mining?

I never said it was but as this thread started with a premise of a lunar elevator as a means to get asteroidal material to create space industry I was simply interested in how best to get over the series of problems that asteroid mining will have. I seriously suspect that access to the minerals of the Moon will easily beat any asteroid mining financially as well as in simplicity. But the Moon is lowsy with volatiles and if we can get access to them then it will make infrastructure creation on the Moon and increasing our prescence in space a lot easier.

Grypd · 2006-02-19 13:53:50

Grypd: Anchoring machinery to surfaces using techniques gained from Earth megaprojects plus ingenuity that engineers thrive on, is what we humans do!

As long as we can anchor I suppose. In effect tieing yourself to the asteroid then burning a hole and corkscrewing yourself in should give enough of a hold. You can then use the cables as a means to securely travel machinery across an asteroids surface.

Lunar space elevator concept escapes me, if what is meant has to be synchronous with the Moon's rotation. To me, the material mined from NEA's would be used in weightless space to construct and maintain space habitats, spacecraft and more refining facilities.

The problem is that refining material in space will be difficult and mostly our most efficient techniques work best with gravity to do the separation. We can artificially create gravity by spinning but this causes other not so easily correctable problems for us. Making components also will be easier to do in a gravity well but a lunar space elevator will give the moon a lot of advantages as an Industrial site, the low g will give us the best of both worlds and certainly economically as well as in efficiency refining then sending the materials up an elevator will be likely the best method. Especially as the only thing an elevator will need is electricity to operate and this the Moon can provide easily.

GCNRevenger · 2006-02-19 14:39:12

"Did I mention cutting rock with these cables no I mentioned grappling them. All they have to do is ensure that we can put machinery close enough to the surface and locate above a spot that our machinery can put a hole that we can then drill into to provide a secure means to operate on the asteroid.

You do not understand. You can't drill or cut or apply any pressure to the surface of the rock without a down force. It is not a matter of putting the drill or digger simply close to the surface, but you have to actively push the drill/digger/etc against the surface you want to drill. Otherwise, start up your drill or whatever and press it to the asteroid, and what happens? Your drill rig gets pushed off the surface instead of biting into the rock.

You can't even efficiently cut initial "pilot" holes for anchors

"If we search for asteroids of the size between 10 to 250 metres size..."

...Are hard to find, spaced far apart by distance and relative velocity, and are probobly too small to be worth mining.

"Especially as the only thing an elevator will need is electricity to operate and this the Moon can provide easily."

Not quite. A Lunar elevator's anchor orbit is a Lagrange point, which while fairly stable, is not totally stationary. Some stationkeeping propellant would be needed, and the bigger the Lagrange station, the more you would need.

Grypd · 2006-02-19 15:28:22

"Did I mention cutting rock with these cables no I mentioned grappling them. All they have to do is ensure that we can put machinery close enough to the surface and locate above a spot that our machinery can put a hole that we can then drill into to provide a secure means to operate on the asteroid.
You do not understand. You can't drill or cut or apply any pressure to the surface of the rock without a down force. It is not a matter of putting the drill or digger simply close to the surface, but you have to actively push the drill/digger/etc against the surface you want to drill. Otherwise, start up your drill or whatever and press it to the asteroid, and what happens? Your drill rig gets pushed off the surface instead of biting into the rock.

But as noted they would be grappled to the object they will be secure and they will be able to push against the surface having been attached by cables and these will be tight. You will be able to use these cables to move around the asteroid and by burning a hole you can make yourself even more secure. The drill rig will not be able to leave the surface without a deliberate release. That is why you have cables it is the only way to secure yourself to such a body.

You can't even efficiently cut initial "pilot" holes for anchors

Unless your secure right over the point and burn your way in. You can even sandblast a hole in if needed but focused superheat will be a lot better.

"If we search for asteroids of the size between 10 to 250 metres size..."
...Are hard to find, spaced far apart by distance and relative velocity, and are probobly too small to be worth mining.

Are not hard to find and as we are activelly discovering 10 a day with space watch simply on a basis of self preservation. And if we want to mine them it will depend what they are made of. If a 250 metre body made of pure PGM guess what thats more than we have used ever. But any stony iron or pure iron asteroid will be worth investment. Larger NEA's which are chondrites will be of more use for Volatile extraction.

"Especially as the only thing an elevator will need is electricity to operate and this the Moon can provide easily."
Not quite. A Lunar elevator's anchor orbit is a Lagrange point, which while fairly stable, is not totally stationary. Some stationkeeping propellant would be needed, and the bigger the Lagrange station, the more you would need.

Mass driver use of slag? Got a use for it now

Commodore · 2006-02-19 16:12:30

Even with lots of impact sites on the moon, its still a finite resouce, and your going to have to sift through a lot of other stuff just to get whats concentrated in a asteroid. And oh by the way, your then going to have to get it of the moon. The moon will come first, but your always going to be looking for a smaller gravity well.

I think the key to addressing a lot of of the voiced concerns is proper surveying. You absolutely need to know where the centers of gravity are, were the solid chucks are and so on. Ground penetrating rader, explosives and sesmic sensors, and so on.

For the forseeable future, smaller targets no more than a couple hundred meters in diameter should be manageable. At that size you can have prebuilt scaffolding built on the moon and assembled in orbit. By wrapping the scaffolding around it you can spread out the stress of pushing against it by attaching it to the asteroid at multiple points. If we can field the power sources, I think high powered lasers will be more effective than drills. The scaffolding could support any number of scoops to clean off loose material, as well as arms to grab peices, as well as cutting lasers, perhapes drills, and personal platforms. Using lasers, drills and explosives, ect, peices are gradually chipped off. Material would then be sent to either end for limited processing. Processing probably won't do much more that grind up raw peices and seperate them down to base minerals and melt them into hulks of whatever minerals are useful. These would have be clumped together for storage.

Crew quarters would basically be just like any other interplanetary craft in terms of life support systems ranging from simulated g to food production. The bulk of the crew would operate and maintain the mining equipment. Some small workshops could produce spare parts out of materials gathered.

In time, larger asteroids could be exploited with larger craft built with exploited material, but you have to start small. This method also only applies to asteroids with solid interiors. Crumbly ones would be much harder. It might be possible to melt the top few inches of soil using microwaves (someone described a way to melt roads on the Moon, however that was done) and attach to that, and then dig through the crust. Kind of like holding an egg and poking a hole in it and sucking out the yoke.

dicktice · 2006-02-19 20:54:51

GCNR:
My supposition that an asteroid rotates about a single axis was wrong (as you point out) which would of course complicate any initial landing procedure, unless (a) the rate of rotation is slow enoutg and (b) the shape regular enough for the prospecting spacecraft's control thrusters to compensate for. But, since every asteroid has a single centre-of-mass, once that is determined and modelled by the onboard computer, laser drill rigs spotted and anchored about the surface and aimed so their powerful beams will intersect at the centre-of-mass would create the hollow site from which to start--using remote presence from nearby without actually having to land.

Solar-thermal steam rockets, driving water-ice encapsulated product at regular intervals, at the same temperaure as H2/O2 electrolized chemical rockets would have equivalent specific impulses--trading the complicarted electrolyzing and gas storage gear for a much simpler to maintain solar collector mirror arrangement--for transporting product to any destination in space where it is needed.

The prospecting ship, by remaining initially off the surface, the uninterrupted solar power could be generated aboard for living purposes as well as for the needs of any refining processes.

Power for the drilling would be transmitted to the anchored surface laser drill rigs by a (to be determined) self-orienting laser power transmission/receiver/heat conversion system, which would double as a means of slowing rotation in various ways by means of conservation of angular momentum in various ways mentioned in some of the other replies.

The water extraction from the chondrite asteroids by heating, estimated to reach 40 percent of the total mass as needed for shielding, propulsion and delivered product. The mined material, via control of the centre-of-mass oriented shafts, would be retained inside the asteroid until rotation rate is no longer a factor, and perhaps even manipulated to help slow the rotation, before being ejected from the shafts to the foundry/refractory facility to be processed.

The Moon's surface minerals are the diluted remains of asteroidal impacts themselves, it seems, suggesting that asteroid mining could be hundreds of times more productive to prospect for, once the techniques have been established.

Realtime automation from nearby adaptive remote presence spacecraft of the entire process, and monitored at intervals imposed by distance from Lunar and/or Earth stations, will lead to and pay for the eventually utilization of similar for unmanned interplanetary exploration throughout the Solar System.

BWhite · 2006-02-19 23:32:56

There are plenty of smaller, manageable bits of impacted asteroids on the Lunar surface; why oh why is it so hard to believe that mining and refining them there is inherintly and overwhelmingly superior to asteroid mining?

Wow! That is pretty much what I just posted here.

I am more sanguine that GCNRevenger about the long term prospects for asteroid mining. That said, mining fragments that have come to a nice stop, 3 days from Earth (on the moon!) seems like a much better place to start.

Okay, maybe we run out eventually. But not within the next few decades and practice on the moon will be invaluable.

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Re: Lunar Space Elevator

#20 2006-02-19 13:53:50

Re: Lunar Space Elevator

#21 2006-02-19 14:39:12

Re: Lunar Space Elevator

#22 2006-02-19 15:28:22

Re: Lunar Space Elevator

#23 2006-02-19 16:12:30

Re: Lunar Space Elevator

#24 2006-02-19 20:54:51

Re: Lunar Space Elevator

#25 2006-02-19 23:32:56

Re: Lunar Space Elevator

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