Project to mine asteroids for water (and precious metals) has begun.

[kedo1981]

All the stuff the asteroid is made of is only valuable in space.
Apart from samples for research the gold and platinum, water and so on is only worth anything because it’s already in space, because it don’t have to tossed into orbit.

[LarianLeQuella]

Originally Posted by Rasmus

Squeeeeeeeeeeeeeeeee!

My inner 6 year old is telling me to apply immediately.
My inner 30-something year old is trying to come up with a rationalization still...

Almost ditto. I have an outer 40-something year old... And my inner is closer to 12.

[Rasmus]

Originally Posted by LarianLeQuella

Almost ditto. I have an outer 40-something year old... And my inner is closer to 12.

Clearly, we should apply as a team!

[uruk]

I almost went for it to. My soldering skills are just below Mil-Spec and I have been cramming robotics into my noodle at an alarming rate.

.....Then again my wife has been talking about moving out west.

[Rasmus]

Originally Posted by uruk

I almost went for it to. My soldering skills are just below Mil-Spec and I have been cramming robotics into my noodle at an alarming rate.

My skills can be summarized as "I have seen a soledering iron once and i have LEGO." Still....

[uruk]

Originally Posted by Rasmus

My skills can be summarized as "I have seen a soledering iron once and i have LEGO." Still....

Soldering is a good skill to learn. It can save you a few bucks down the road.

And if you like LEGO try Mmindstorm NXT and TETRIX and learn ya some micro-controller/robot skillz!

From there you can work your way up to VEX, Arduino/Parallax then Robotics with your PC and Microsoft Robotics Studio.

By then you will be ready to build robots from scratch and program them in just about any programing language.

[Hellbound]

Originally Posted by OnlyTellsTruths

I seriously doubt hitting a target from space with "meteors" is easy or even possible. Unless this pit you are talking about is tens of thousands of square miles.

Not so much, just a matter of applying force to it. We routinely launch rockets from Earth to hit Mars at specific pre-defined trajectories and in targetted locations...a feat roughly equivalent to firing a rifle bullet in New York and splitting a human hair in Los Angeles. And that's done using minimal corrections (fuel=weight=cost). The main difference is in scale. I'd suspect initial adjustments would be witht he intnention to bring the rock close to Earth, adjust into an orbit, then de-orbit at the correct time and force to drop it where we want it.

Originally Posted by punshhh

Has it occurred to anyone that these lumps of rock cause mass extinction events?
Quite a liability.

Only the big ones, and only at pretty good speeds. If you're intentionally de-orbiting, you'd also slow them down relative to Earth, and I seriously doubt anyone would be looking at crashing multiple-kilometer rocks into the surface.

Interestingly, assuming this becoems feasible, I'd suspect the high demand asteroids would be those that are already close in velocity to Earth that would require minimal energy to bring close to the planet...which are not necessarily the ones closest to us at any given point. I'd also suspect huge lead times...apply a force to an asteroid, wait five years for that force to bring it close to Earth, then adjust corse for the impact.

[Checkmite]

Originally Posted by Andrew Wiggin

I think legally it would be a lot simpler to just move the rock, drop it on land you already own, and then mine the land. The ownership then becomes pretty obvious. The only precedent we have for actually marking an extraterrestrial body are the flags the USA put on the moon, but the russians followed that up with a grenade, its shell made of prefragmented claim markers, each one engraved with the hammer and sickle. A bit harder to recover or obliterate that sort of mark than to disappear a few flags.

ETA the russians dropped their grenade on the moon from their 'luna 2' mission, before we planted a flag. I guess that makes it even more a grey area.

It doesn't. It wasn't "the Russians" that did that; it was the Soviets. And there are no more Soviets, rendering any potential claims they may have had moot.

There's allegedly international laws against nations claiming lunar or asteroid real estate; I don't know if there are any laws pertaining to private claims; but even if there are, there's nothing stopping you from asserting a claim on any of these things. There just won't be any courts on Earth you can use to defend your claim.

[Mark6]

Originally Posted by OnlyTellsTruths

I seriously doubt hitting a target from space with "meteors" is easy or even possible. Unless this pit you are talking about is tens of thousands of square miles.

How is it different from any de-orbiting object? Which is done routinely, and accurately enough to snag them from the air by helicopters (ok, that part is not routine).

[Checkmite]

At the press conference, they never announced any intention to "move" asteroids. They spoke only of identifying and selecting asteroids that already transited the Earth/Moon system and were already of the right orbital characteristics to make mining them feasible.

[Checkmite]

Originally Posted by Mark6

How is it different from any de-orbiting object? Which is done routinely, and accurately enough to snag them from the air by helicopters (ok, that part is not routine).

Think about that - deorbiting an object of known flight characteristics and controllable attitude versus a randomly-shaped tumbling question mark. How accurately were they able to predict the deorbiting of certain non functioning European spacecraft over the past year?

[Mark6]

Originally Posted by Checkmite

Think about that - deorbiting an object of known flight characteristics and controllable attitude versus a randomly-shaped tumbling question mark. How accurately were they able to predict the deorbiting of certain non functioning European spacecraft over the past year?

Anyone with half a brain would a) stop the tumbling, and b) provide for last-minute course corrections.

If you cannot do that, you should not attempt a de-orbit.

[I Ratant]

Originally Posted by OnlyTellsTruths

I seriously doubt hitting a target from space with "meteors" is easy or even possible. Unless this pit you are talking about is tens of thousands of square miles.

.
We have ICBMs and other things that are intended to get into space, and return with malice aforethought.
De-orbiting a big pile of stuff to land in a non-nuclear event on the bad guy is a good idea.
I have a few landing spots in mind right now.

[phunk]

Originally Posted by Mark6

Anyone with half a brain would a) stop the tumbling, and b) provide for last-minute course corrections.

If you cannot do that, you should not attempt a de-orbit.

You can't do last minute corrections with something that big.

What they need is processing in space and some sort of cheap reentry capsule for dropping the products to earth in batches small enough to control.

[Pope130]

Process the material in space, then cast it into a re-entry vehicle shape. Heat shield it with waste material from the refining process. Attach a guidance and propulsion package. Bring it back just as you would a recoverable vehicle that you had launched. Splash down or land impact (with the guidance and propulsion package recovered seperately), or cast it in a lifting vehicle shape and belly land it on a dry lake bed ("The Six Million Dollar Rock").

[Mark6]

Originally Posted by phunk

You can't do last minute corrections with something that big.

What they need is processing in space and some sort of cheap reentry capsule for dropping the products to earth in batches small enough to control.

See last sentence of my previous post. If something is too big to do last-minute course corrections, it should not be de-orbited. In fact, no goverment would allow you to do that. Phrase "reckless endangerment" does not begin to cover it.

[quarky]

Originally Posted by Madalch

Also from wiki: Of the 239 tonnes of platinum sold in 2006, 130 tonnes were used for vehicle emissions control devices, 49 tonnes for jewelry, 13.3 tonnes in electronics, and 11.2 tonnes in the chemical industry as a catalyst. The remaining 35.5 tonnes went to various other minor applications, such as electrodes, anticancer drugs, oxygen sensors, spark plugs and turbine engines.

Thanks for that homework, Madalch. The nerd in me started to calculate the radius of the 239 tonne blob of platinum. Not that big, actually, to put it in layman's terms.
Interesting, the "239 tonnes SOLD". I wonder how that correlates to the amount mined? I would suspect that a lot of it is stashed before its even on the market, though I've nothing by way of evidence.

Here's an unrelated half-baked idea: (Make that quarter-baked):

In space mining, have a means of producing uniform sized rods of the various precious metals. Assemble the rods into a geodesic spherical structure. At the top of our atmosphere, enclose the structure with a membrane.
This essentially creates a 'vacuum balloon". If the weight of the inner structure was similar to the weight of the air it would have enclosed at sea level, it would fall slowly to the ground, after being nudged that way, provided their was a valve of sorts that would allow air in, gradually.

On the ground, the dome is disassembled, and the membrane put to other use, or sent back up.
Alternatively, without the geodesic structure, a balloon of gaseous platinum could be lowered to Earth. Though, I suspect, that's even stupider than the first idea.

[phunk]

Originally Posted by Mark6

See last sentence of my previous post. If something is too big to do last-minute course corrections, it should not be de-orbited. In fact, no goverment would allow you to do that. Phrase "reckless endangerment" does not begin to cover it.

Yeah, I was agreeing with you and offering an alternative. Don't deorbit an asteroid, just deorbit the stuff mined from it.

[GlennB]

What I see here is a "project" where keen scientists scam money from insanely rich dudes in order to carry out cool sciencey stuff, on good pay, for as long as they can keep up the pretence that there might be a payback one day.

When the first $multi-million deadline over-runs by years, or a $multi-million launch goes wrong, or a payload fails to deploy, or the asteroid turns out to have < 1/jillionth % platinum (1 gram retrievable), or the return capsule burns up, then I strongly suspect the whole caboodle will be exposed as the nonsense it always was.

The human race has better things to do with its time and money than this kind of crap. Just go dig in some extra mountains, ffs

[soylent]

Originally Posted by GlennB

Just go dig in some extra mountains, ffs

Platinum, osmium, gold, palladium, iridium, ruthenium, rhenium and rodium are all siderophiles; they like to stick toghether with iron and they have very little affinity for oxygen.

These elements almost entirely sink to the earths core and there are very slim pickings in the Earth's crust(mostly from old asteroid impacts!).

[OnlyTellsTruths]

Originally Posted by Hellbound

I'd suspect initial adjustments would be witht he intnention to bring the rock close to Earth, adjust into an orbit, then de-orbit at the correct time and force to drop it where we want it.

That would work for hitting an area tens of thousands of square miles (maybe 200 miles in diameter?), which is what I was talking about. Not for "hitting a big pit" which is what was being claimed.

I assume the big pit is a few square miles, it still hasn't been clarified.

Originally Posted by Mark6

How is it different from any de-orbiting object? Which is done routinely, and accurately enough to snag them from the air by helicopters (ok, that part is not routine).

Because in that case you can track them. As opposed to hitting a target from space.

Please re-read the initial claim (bolding mine):

Originally Posted by Andrew Wiggin

If you didn't care about getting them down intact and can afford to waste a bit of metal, just buy a big open stretch of desert someplace, dig a big conical pit and drop meteors into it. (the pit might even be self digging, but the first few meteors would have higher losses. After the pit gets deep enough, most of the splatter gets intercepted by the walls) After a year of bombardment of one particular place, bring in conventional mining equipment to dig out the metal, and move the bombardment area to another patch of desert.

We are discussing what size area would be possible to hit by "dropping" rocks from orbit. No re-adjusting the trajectory after the initial drop allowed.

I'm quite sure the target would have to be nearly the size of Kansas... I'm pretty sure that repeatedly hitting a "big pit" would be impossible. No matter how detailed your calculations are before the drop.


ETA: This does not mean that I disagree completely with Andrew's idea. Dropping huge chunks of the mineral from orbit and "hopefully" tracking where they land could be the cheapest way to deliver the payload to Earth. Just pray it doesn't get much off course and hit anyone that is wealthy, or anyone that is wealthy's property.

[Andrew Wiggin]

Google 'rods from god' for the idea of using metal chunks with primitive guidance as weapons. Supposedly able to hit a tank sized target from orbit with very little guidance. Look at the early space program to see what can be done with unguided reentry vehicles; we almost always had a ship waiting for the capsules on splashdown. I think you're drastically underestimating what we can do. I don't think I was making an extraordinary claim.

[Andrew Wiggin]

Originally Posted by GlennB

What I see here is a "project" where keen scientists scam money from insanely rich dudes in order to carry out cool sciencey stuff, on good pay, for as long as they can keep up the pretence that there might be a payback one day.

When the first $multi-million deadline over-runs by years, or a $multi-million launch goes wrong, or a payload fails to deploy, or the asteroid turns out to have < 1/jillionth % platinum (1 gram retrievable), or the return capsule burns up, then I strongly suspect the whole caboodle will be exposed as the nonsense it always was.

The human race has better things to do with its time and money than this kind of crap. Just go dig in some extra mountains, ffs

Conspiracy theories is thataway-------------->

[Andrew Wiggin]

Originally Posted by quarky

Here's an unrelated half-baked idea: (Make that quarter-baked):

In space mining, have a means of producing uniform sized rods of the various precious metals. Assemble the rods into a geodesic spherical structure. At the top of our atmosphere, enclose the structure with a membrane.
This essentially creates a 'vacuum balloon". If the weight of the inner structure was similar to the weight of the air it would have enclosed at sea level, it would fall slowly to the ground, after being nudged that way, provided their was a valve of sorts that would allow air in, gradually.

On the ground, the dome is disassembled, and the membrane put to other use, or sent back up.

Unfortunately the idea of the vacuum balloon doesn't work. No known material can hold out atmospheric pressure while being lighter than the air it displaces. You might be able to fill it with hydrogen, and make a zeppelin of sorts. You'd still need to build it to withstand the stress and heating from decelleration from orbital velocity, which doesn't suggest light construction.

Quote:

Alternatively, without the geodesic structure, a balloon of gaseous platinum could be lowered to Earth. Though, I suspect, that's even stupider than the first idea.

Only a stupid idea when you look up the boiling point of platinum, and compare it to whatever you'd have to make the balloon out of.

[Rasmus]

Originally Posted by Andrew Wiggin

Look at the early space program to see what can be done with unguided reentry vehicles; we almost always had a ship waiting for the capsules on splashdown. I think you're drastically underestimating what we can do. I don't think I was making an extraordinary claim.

How accurate was that process, though, compared to the requirements here?

How many ships were out there, and how far did the one ship still have to move to be waiting at the right stop?

How often did "almost always" not work? They did have the entire ocean to hit, right?

[OnlyTellsTruths]

Originally Posted by Andrew Wiggin

Google 'rods from god' for the idea of using metal chunks with primitive guidance as weapons. Supposedly able to hit a tank sized target from orbit with very little guidance. Look at the early space program to see what can be done with unguided reentry vehicles; we almost always had a ship waiting for the capsules on splashdown. I think you're drastically underestimating what we can do. I don't think I was making an extraordinary claim.

OK, what I believe you aren't understanding is that when we "had a ship waiting for the capsules on splashdown" it was because we were tracking it.

The ships were ready in a large general area, and then tracking the object allowed us to drive to it and retrieve it. Not because we aimed for that specific spot (where the ships ended up retrieving the object) from space, which is what your claim was. Big difference.

[pakeha]

Originally Posted by Checkmite

Yes.

Sweet!

[Andrew Wiggin]

Originally Posted by OnlyTellsTruths

OK, what I believe you aren't understanding is that when we "had a ship waiting for the capsules on splashdown" it was because we were tracking it.

The ships were ready in a large general area, and then tracking the object allowed us to drive to it and retrieve it. Not because we aimed for that specific spot (where the ships ended up retrieving the object) from space, which is what your claim was. Big difference.

We were tracking them, but we also knew pretty much exactly where they were going to land. You can't just move an aircraft carrier several hundred miles in a few minutes, and 'tracking it' doesn't change that, because reentry speeds are multiple kilometers per second up until the last few moments. We're talking about circumnavigating the planet in an hour and a half types of speed. To be waiting for it, you have to know where it'll land. As another poster upstream mentioned, there have been spy satellites that have dropped film capsules into the atmosphere that we snag with nets from aircraft. Yeah, the plane can fly around a bit, but the capsule is dropping like a stone. (or a meteor) Either you know exactly where it'll land, to be under it with a net at that exact moment, or you lose it into the ocean. (or to the waiting russian 'fish trawler' waiting below (Yah Checkmite. I said russian again. I know it's the USSR.) No opportunity for a second pass, and no opportunity to be more than maybe a mile off, if that. You can track it, but you've got to be in the exact right spot too.

I really don't know why you're doubting this. The entire history of the space program is pretty much an open book. I can understand that the latest random satellite reentries have given a picture of something chaotic and unpredictable, but that's because we're not TRYING to shoot those into the atmosphere, rather just them slowly dragging away at the upper atmosphere till they take a big enough 'bite' into it and reenter. Things like solar flares are always moving the upper atmosphere up a bit, so the 'bite' a randomly reentering body gets from it is variable and unpredictable. These are defunct satellites with no control, so they're tumbling randomly too and that changes how much friction they're getting. That's why we can only tell where they'll land in terms of drawing a line and saying 'somewhere along here'. When you're shooting something into the atmosphere on purpose you're in that variable upper part for fractions of a second, and you get to pick things like angle and attitude that control how fast you're going to slow down. If engineers in the 60's could solve that problem with slide rules and get within a few miles, then modern engineers with computers can get within feet. When I was visualizing a pit to drop asteroids into, I was thinking maybe 50 meters across, if that. The only reason you'd want a big stretch of desert is that no one would want to live next to the pit unless they were completely deaf.

[GlennB]

Originally Posted by soylent

Platinum, osmium, gold, palladium, iridium, ruthenium, rhenium and rodium are all siderophiles; they like to stick toghether with iron and they have very little affinity for oxygen.

These elements almost entirely sink to the earths core and there are very slim pickings in the Earth's crust(mostly from old asteroid impacts!).

Thanks for your thoughtful reply to my flippant post (I'd take slight exception to your comment about 'mostly old asteroid impacts', as igneous deposits seem to be the primary occurence). But it sent me off looking up the occurence and extraction of some of these metals, and Iridium caught my eye.

It seems some meteorites can be ~0.5ppm Iridium, so let's go totally wild and suppose an asteroid with 1,000ppm Iridium is located. That's still a huge amount of spoil to make 1t of Iridium, so mining and shipping the ore to Earth appears to be an extremely (prohibitively?) expensive option in terms of weight alone. Processing in situu would be an extremely process-intensive job (see http://en.wikipedia.org/wiki/Iridium#Production ) requiring electrorefining equipment and multiple reagents, among other stuff.

And the mining and crushing equipment itself, of course. And robotic gear to operate in ultra-low gravity, and missions to perform maintenance, and ....

Iridium costs ~$20,000,000 a ton here on Earth, by my calculations.

I'm still convinced it's no more than a sexy pipe-dream.

[nvidiot]

Originally Posted by Andrew Wiggin

We were tracking them, but we also knew pretty much exactly where they were going to land. You can't just move an aircraft carrier several hundred miles in a few minutes, and 'tracking it' doesn't change that, because reentry speeds are multiple kilometers per second up until the last few moments. We're talking about circumnavigating the planet in an hour and a half types of speed. To be waiting for it, you have to know where it'll land. As another poster upstream mentioned, there have been spy satellites that have dropped film capsules into the atmosphere that we snag with nets from aircraft. Yeah, the plane can fly around a bit, but the capsule is dropping like a stone. (or a meteor) Either you know exactly where it'll land, to be under it with a net at that exact moment, or you lose it into the ocean. (or to the waiting russian 'fish trawler' waiting below (Yah Checkmite. I said russian again. I know it's the USSR.) No opportunity for a second pass, and no opportunity to be more than maybe a mile off, if that. You can track it, but you've got to be in the exact right spot too.

I really don't know why you're doubting this. The entire history of the space program is pretty much an open book. I can understand that the latest random satellite reentries have given a picture of something chaotic and unpredictable, but that's because we're not TRYING to shoot those into the atmosphere, rather just them slowly dragging away at the upper atmosphere till they take a big enough 'bite' into it and reenter. Things like solar flares are always moving the upper atmosphere up a bit, so the 'bite' a randomly reentering body gets from it is variable and unpredictable. These are defunct satellites with no control, so they're tumbling randomly too and that changes how much friction they're getting. That's why we can only tell where they'll land in terms of drawing a line and saying 'somewhere along here'. When you're shooting something into the atmosphere on purpose you're in that variable upper part for fractions of a second, and you get to pick things like angle and attitude that control how fast you're going to slow down. If engineers in the 60's could solve that problem with slide rules and get within a few miles, then modern engineers with computers can get within feet. When I was visualizing a pit to drop asteroids into, I was thinking maybe 50 meters across, if that. The only reason you'd want a big stretch of desert is that no one would want to live next to the pit unless they were completely deaf.

Being a skeptic and all, it would be nice if you could look up some evidence that you can pinpoint land an unaerodynamic mass with little trajectory control in the manner you describe.

Afaik the landing points for capsules like Apollo had miss distances measured in kilometers.

[Bodhi Dharma Zen]

Originally Posted by OnlyTellsTruths

...and by "begun" I mean that it is just off the drawing board.


Billionaire-backed asteroid mining venture starts with space telescopes

Bitter news, they want to go there for the wrong reasons...

[quarky]

Originally Posted by Andrew Wiggin

Unfortunately the idea of the vacuum balloon doesn't work. No known material can hold out atmospheric pressure while being lighter than the air it displaces. You might be able to fill it with hydrogen, and make a zeppelin of sorts. You'd still need to build it to withstand the stress and heating from decelleration from orbital velocity, which doesn't suggest light construction.



Only a stupid idea when you look up the boiling point of platinum, and compare it to whatever you'd have to make the balloon out of.

I don't think that the vacuum balloon has been proven un-doable.
As you likely know, the ratio of the surface area mass to the volume mass grows more favorable as radius rises. In synchronous orbit, the decent could be gentle. Allowing the gradual introduction of outside air would lessen the demands of the membrane...though, I don't suppose it would be much different than a parachute.

[OnlyTellsTruths]

Originally Posted by Andrew Wiggin

We were tracking them, but we also knew pretty much exactly where they were going to land. You can't just move an aircraft carrier several hundred miles in a few minutes, and 'tracking it' doesn't change that, because reentry speeds are multiple kilometers per second up until the last few moments. We're talking about circumnavigating the planet in an hour and a half types of speed. To be waiting for it, you have to know where it'll land. As another poster upstream mentioned, there have been spy satellites that have dropped film capsules into the atmosphere that we snag with nets from aircraft. Yeah, the plane can fly around a bit, but the capsule is dropping like a stone. (or a meteor) Either you know exactly where it'll land, to be under it with a net at that exact moment, or you lose it into the ocean. (or to the waiting russian 'fish trawler' waiting below (Yah Checkmite. I said russian again. I know it's the USSR.) No opportunity for a second pass, and no opportunity to be more than maybe a mile off, if that. You can track it, but you've got to be in the exact right spot too.

I really don't know why you're doubting this. The entire history of the space program is pretty much an open book. I can understand that the latest random satellite reentries have given a picture of something chaotic and unpredictable, but that's because we're not TRYING to shoot those into the atmosphere, rather just them slowly dragging away at the upper atmosphere till they take a big enough 'bite' into it and reenter. Things like solar flares are always moving the upper atmosphere up a bit, so the 'bite' a randomly reentering body gets from it is variable and unpredictable. These are defunct satellites with no control, so they're tumbling randomly too and that changes how much friction they're getting. That's why we can only tell where they'll land in terms of drawing a line and saying 'somewhere along here'. When you're shooting something into the atmosphere on purpose you're in that variable upper part for fractions of a second, and you get to pick things like angle and attitude that control how fast you're going to slow down. If engineers in the 60's could solve that problem with slide rules and get within a few miles, then modern engineers with computers can get within feet. When I was visualizing a pit to drop asteroids into, I was thinking maybe 50 meters across, if that. The only reason you'd want a big stretch of desert is that no one would want to live next to the pit unless they were completely deaf.

OK, first of all your initial claim was "drop" not "shoot".

Originally Posted by Andrew Wiggin

If you didn't care about getting them down intact and can afford to waste a bit of metal, just buy a big open stretch of desert someplace, dig a big conical pit and drop meteors into it. (the pit might even be self digging, but the first few meteors would have higher losses. After the pit gets deep enough, most of the splatter gets intercepted by the walls) After a year of bombardment of one particular place, bring in conventional mining equipment to dig out the metal, and move the bombardment area to another patch of desert.

Even if I allow you to change your claim from "drop" to "shoot" (or even shoot with considerable velocity) there is no way to hit an area that is measure with square meters. That just isn't how re-entry works.

With "drop" you would need tens of thousands of square miles, and the odds of repeatedly hitting the same spot are basically nil.

With "shoot at high velocity" you would still need an area of several square miles and the odds of repeatedly hitting the same spot would still be very low.

Originally Posted by nvidiot

Being a skeptic and all, it would be nice if you could look up some evidence that you can pinpoint land an unaerodynamic mass with little trajectory control in the manner you describe.

Afaik the landing points for capsules like Apollo had miss distances measured in kilometers.

...and on top of that there is a big difference between a semi-controlled capsule re-entry and just "dropping" a big rock from space.

[WhatRoughBeast]

Precision reentry is hard. As an example of high accuracy, consider ICBMs with MIRVs, which surely consitute a fair approximation of the best you can do. For these birds, CEP is about 100 meters.

Arguing that "dropping" a rock implies no terminal guidance seems iffy to me. Considering the value of a few hundred tons of platinum group metals, adding a terminal guidance package would seem a no-brainer.

[NewtonTrino]

Originally Posted by GlennB

Thanks for your thoughtful reply to my flippant post (I'd take slight exception to your comment about 'mostly old asteroid impacts', as igneous deposits seem to be the primary occurence). But it sent me off looking up the occurence and extraction of some of these metals, and Iridium caught my eye.

It seems some meteorites can be ~0.5ppm Iridium, so let's go totally wild and suppose an asteroid with 1,000ppm Iridium is located. That's still a huge amount of spoil to make 1t of Iridium, so mining and shipping the ore to Earth appears to be an extremely (prohibitively?) expensive option in terms of weight alone. Processing in situu would be an extremely process-intensive job (see http://en.wikipedia.org/wiki/Iridium#Production ) requiring electrorefining equipment and multiple reagents, among other stuff.

And the mining and crushing equipment itself, of course. And robotic gear to operate in ultra-low gravity, and missions to perform maintenance, and ....

Iridium costs ~$20,000,000 a ton here on Earth, by my calculations.

I'm still convinced it's no more than a sexy pipe-dream.

I see, it's hard and nobody has done it yet, therefore it's impossible. Good point.

Then again maybe we actually can figure it out. There are a lot of different strategies that could be used to refine ore in space. For example heat a rock using a array of mirrors until it's close to melting and spin it to separate by mass. Eventually it should form a disc which you can then cut the edge off of (possibly using a laser) to peel off the ore into a strip. That's just one idea. There are plenty of other techniques that could work. Remember that you have hard vacuum and a lot of sunlight (energy) to work with.

Also if you had actually read about any of this you would realize their first mining goal is to simply mine ice and process it into useful on orbit consumables like rocket fuel, air and water.

Of course before that they have a bunch of other interim goals that are easily tracked.

The go cheap and build a lot of redundancy through numbers is something NASA has never tried. There is no reason their space hardware can't be quite cheap if they mass produce.

[Checkmite]

In the press conference, they clarified that rare elements are certainly on the radar for far in the future but by far their primary target is water.

[WhatRoughBeast]

Originally Posted by NewtonTrino

For example heat a rock using a array of mirrors until it's close to melting and spin it to separate by mass. Eventually it should form a disc which you can then cut the edge off of (possibly using a laser) to peel off the ore into a strip. That's just one idea.

And someone has been reading John Ringo. Who really didn't pay attention to numbers.

Please run up an estimate of the infrasructure costs on this one. Include the mirror area required, the stabilization/pointing mechanism construction and power requirements for the mirrors and, oh yes, make sure you take into account the reflectivity of the mass and the thermal emissions of the object when hot. Then note that the mirrors need to be lifted into orbit.

Let's see, then there's the question of how you spin up multiton objects to the appropriate rotation rate (note that the object has to be in one piece with no internal flaws, or it will fly apart - you can't start with a bunch of rubble). And also note that the object has to actually melt, not just get "close to melting".

The list goes on and on. Any particular point may be solvable, but I'm not taking bets that all of them will be doable, particularly at reasonable cost.

[OnlyTellsTruths]

Originally Posted by WhatRoughBeast

Precision reentry is hard. As an example of high accuracy, consider ICBMs with MIRVs, which surely consitute a fair approximation of the best you can do. For these birds, CEP is about 100 meters.

Arguing that "dropping" a rock implies no terminal guidance seems iffy to me. Considering the value of a few hundred tons of platinum group metals, adding a terminal guidance package would seem a no-brainer.

If by "drop meteors into it" Andrew meant having a guidance package on them then I apologize. Odd that Andrew didn't clarify that in one of the recent posts though.

[Halfcentaur]

Originally Posted by GlennB

The human race has better things to do with its time and money than this kind of crap. Just go dig in some extra mountains, ffs

Who are you to dictate what other people should be doing with their time and money? Solving the world's problems isn't a matter of there not being enough money, there's more than enough money to do it with plenty left over. If you're not spending every extra penny you have and going without luxuries in order to improve the human race, this comment makes you a hypocrite. You're just ignoring the absurdly small percentage of wealth such a project would spend and focusing on numbers that sound big because they could buy a lot of other things. This is nonsensical and biased.

[NewtonTrino]

Originally Posted by WhatRoughBeast

And someone has been reading John Ringo. Who really didn't pay attention to numbers.

Please, John Ringo writes SF. He had technology from an advanced civilization including AI's and propulsion systems we can only dream of. I'm not saying this is the way to do it, I'm just pointing out there are a lot of ideas we haven't even tried.

Quote:

Please run up an estimate of the infrasructure costs on this one. Include the mirror area required, the stabilization/pointing mechanism construction and power requirements for the mirrors and, oh yes, make sure you take into account the reflectivity of the mass and the thermal emissions of the object when hot. Then note that the mirrors need to be lifted into orbit.

At some scale it's going to be possible. I also object to your idea that mirrors would have to be brought up. The idea should be to bootstrap as quickly as we can to using materials already in space.

Again, I'm not saying this is the "the way". But some combination of cutting, explosion, energy from the sun, use of a vaccum, rotation etc. is going to make some kind of extraction doable I'm sure.

Quote:

Let's see, then there's the question of how you spin up multiton objects to the appropriate rotation rate (note that the object has to be in one piece with no internal flaws, or it will fly apart - you can't start with a bunch of rubble). And also note that the object has to actually melt, not just get "close to melting".
The list goes on and on. Any particular point may be solvable, but I'm not taking bets that all of them will be doable, particularly at reasonable cost.

I never said it was doable, I said it was one idea among many.

There are a lot of ways we can manipulate these objects and a lot of different things we could try.

The idea that people think going after these resources is a waste of time blows my mind.