Asteroid mining? Google billionaires, James Cameron, & "Planetary Resources, Inc"

[kamaz]

Umm - how, exactly? Asteroids don't have a 3.6km/sec gravity well. LEO to LLO is slightly MORE Delta-V than LEO to C3.

It's hard enough to close a business case for getting resources from an Asteroid. The Moon is a LOT harder.

(and before you start on the 'water on the lunar south pole'.... there's water in asteroids as well. Go to the right asteroids and they're 20% water)

Paul Spudis on the issue:

There are, however, some difficulties in mining and using asteroidal material as compared to lunar resources. First is the nature of the feedstock or “ore.” We have recently found that water at the poles of the Moon is not only present in enormous quantity (tens of billions of tons) but is also in a form that can be easily used – ice. Ice can be converted into a liquid for further processing at minimal energy cost; if the icy regolith from the poles is heated to above 0° C, the ice will melt and water can be collected and stored. The water in carbonaceous chondrites is chemically bound within mineral structures. Significant amounts of energy are required to break these chemical bonds to free the water, at least 2-3 orders of magnitude more energy, depending on the specific mineral phase being processed. So extracting water from an asteroid, present in quantities of a few percent to maybe a couple of tens of percent, requires significant energy; water-ice at the poles of the Moon is present in greater abundance (up to 100% in certain polar craters) and is already in an easy-to-process and use form.

The processing of natural materials to extract water has many detailed steps, from the acquisition of the feedstock to moving the material through the processing stream to collection and storage of the derived product. At each stage, we typically separate one component from another; gravity serves this purpose in most industrial processing. One difficulty in asteroid resource processing will be to either devise techniques that do not require gravity (including related phenomena, such as thermal convection) or to create an artificial gravity field to ensure that things move in the right directions. Either approach complicates the resource extraction process.

[kamaz]

Or put it another way: Ores are mined deep undegound, not refined there. Oil is found deep underground, not refined there. How expensive would fish fingers be if they were processed at sea?

Actually, ores are refined above the ground, but near the mining site. Fish are, in fact, processed at sea: https://en.wikipedia.org/wiki/Factory_ship

Think about it this way. There is a marginal cost involved in transporting the ore. If you move processing closer to the mining site, you save on transportation costs, because you don't transport the noninteresting fraction -- which comprises the majority of the mined ore. Here's a real world example: copper ore mined in Poland contains 1.5 - 3% Cu. The ore is then refined on-site to 20-30% and only then shipped to the copper mill. Oil is the exception here, because virtually all fractions of the crude oil are usable, so there is nothing to be saved on transportation costs by refining on-site.

In space, where transportation cost is everything, there is even more reason to move processing close to the source. If your 500 ton asteroid contains 0.1% of Pt (i.e. 0.5 tons), then it makes much more sense to refine on site to 20% concentration and return 2.5 tons instead of 500 tons of unprocessed ore. That means all the platinum from a single asteroid could be returned in one SpaceX Dragon (rated downward payload 3'000kg). Since it is much easier to refine to 20% then it is to refine to 99.99% (which is what the final customer wants), it would make sense to do initial (easy) refining / separation on site, and only return the processed 20% concentrate to Earth for further processing.

[aquitaine]

Asteroid mining, eh? This was, is and will be fairy tales as long as cost of launching kg to orbit is as high as now. These prices must drop first significantly. And by "significant" I consider by few orders of magnitude, not 10% or something like that.

No details was given, obviously. Sceptics here said something to effect of "to be it profitable we would need unobtanium worth 1kk$/kg". And this is assuming anyone would pay for this unobtanium at all. I did not seen anyone trying to deny it, just handwaves.

Many people here are for some reason hunged up on "new definition of 'natural resources'". If you are taking seriously this marketoid speak, I have bridge to sell to you.

SpaceX's quotes are already significantly lower, the Falcon 9H is expected to lift 6 times the payload of an Atlas 5 for the same price. Just because NASA couldn't do it in an economical way doesn't mean private industry also can't.

[djellison]

I'm not going to try and 'defend' asteroid mining vs moon mining. I think both are ludicrous.

Suffice it to say - Asteroids are easier to get to, and easier to get back from, and still, in my opinion, don't make any economic sense for mining.

[antoniseb]

... and still, in my opinion, don't make any economic sense for mining.

I agree in the short term. I think mining makes sense once we can build things in space for commercial use in space.

[ravens_cry]

@marsbug:
Well, fishsticks is an interesting example as there is a fair bit of processing that goes on aboard factory ships.
Furthermore, many mines include refineries in on site (if not in the mine themselves) as transportation is expensive, and it is cheaper to ship the refined product than the raw ore.
This is also my rational for building a refinery on-site.
Let's say a compact automated refinery that weighs 1000 tons. Let's say there is 50:1 dross to commodity ratio. Shipping 20 tons of commodity means you have made back the weight of the refinery.
Now these are pulled out of the blue numbers, but the basic logic of cheaper shipping long term applies applies nonetheless I think.
Now, some have questioned why I say dross is also of value if these guys are not interested in human space flight.
Well, they might not, but others could be. It's something else to sell to their potential customers.

[Warren Platts]

Here is a series of links that explains PRI's real business model:

http://nextbigfuture.com/2012/04/pla...passively.html

http://nextbigfuture.com/2012/04/pla...y-revenue.html

http://eijournal.com/2012/earth-obse...ic-environment

http://planetimager.com/docs/Orbitin...tellations.pdf

Planetary Resources will be putting up hundreds of inexpensive space telescopes with 9 inch mirrors, 2 meter resolution and sub-arcsecond pointing. The passive constellation method for boosting image resolution could achieve centimeter resolution.

So when you walk outside and raise your middle finger to Google PRI, they'll be able to tell which finger it is...

[mutleyeng]

blimey,
they gonna be imaging exo planets huh.

is there anything these fellas cant do i wonder.

[Warren Platts]

Actually, that will be very cool, and it looks they will try it based on having Sarah Seager as one of their scientific advisors...

http://seagerexoplanets.mit.edu/biography.htm

[NEOWatcher]

What's the comparison of delta-v? I haven't run the numbers, but I vaguely remember reading counter intuitive things that the Moon isn't actually the cheapest destination.

Here. According to this link, delta-v for transferring from low-Earth orbit to rendezvous
with the Moon is about 6 km/s. In this link, about 1500 known bodies are easier to get than to Moon.

That seemed counter intuitive to me too. So; I looked up the various Delta-V's to understand why.
So; please correct me if I'm wrong. (I'm getting numbers from wiki)
First; I guess I wasn't clear by what they meant by rendezvous. Now; I see it means landing.
So; that makes sense now.
To "reach" the moon (as in free return) you just need to get past EML1 (3.77)so the moon's gravity well exceeds that of earth. That's where my confusion came in. It's easer to "reach" the moon than an asteroid, but not to rendezvous with it.
What I still don't understand is why Earth escape is less than EML1.

[Warren Platts]

Wrong, at least for some asteroids. There are NEOs that are easier to get (lower delta-v) to than Moon. Low g should help with returning back any materials (why anyone would want that is different matter).


Here. According to this link, delta-v for transferring from low-Earth orbit to rendezvous
with the Moon is about 6 km/s. In this link, about 1500 known bodies are easier to get than to Moon.

Yeah, but the best one on the list only has a 40% savings, and what they don't tell you is that each one of those is "close" to the Earth for about 2 months out of every 20 years....

[cjameshuff]

If this is going to involve manned mining missions to asteroids, someone better invent artificial gravity because prolonged exposure in zero gravity, as most of you know, will lead to muscle breakdown.

Not that manned missions are necessary, but the gravity "problem" was solved long before we got anything into orbit. We don't need anything more than centrifugal gravity.

Anyway, if they can set up a volatile-harvesting operation in orbit, that opens up a huge variety of opportunities. Resupply, orbital tug services, etc. Much of the cost of putting anything in orbit is delta-v, the cost of delta-v is largely propellant, and being able to extract propellant from orbital sources instead of lifting it out of Earth's gravity well on low-Isp high-thrust rockets would be a major benefit. As we do things now, launching to LEO is about half the cost of launching to geosynchronous orbits...with cheap propellant in orbit, a tug service hauling satellites from LEO to GSO could turn quite a profit while reducing the cost of those satellites, while reducing insurance costs by reducing the risk of the satellite getting stranded in the wrong orbit. They could even sell slots on geosynchronous orbital busses that provide power, stationkeeping, backup communications, and regular access by robotic servicing missions, vastly reducing the complexity and risk of putting hardware in orbit...all ultimately resulting from availability of volatiles from orbital sources. There's numerous large potential markets in orbit just waiting for someone to come along and provide goods and services.

Returning large quantities of anything to Earth is a very long term goal, but it's also not remotely as expensive as sending mass in the other direction. One approach...shape a crude iron shell, possibly give it some minimal heat shielding, stuff your payload inside if it's not embedded in the iron itself, and drop it off with a tug. Once you have enough infrastructure set up in orbit, the only continuing cost is propellant...which once again, does not have to be launched from Earth.

That requires a fair bit of infrastructure for processing in orbit, which will take time and money to put in place...but these people are explicitly not looking for a short term profit. In the early stages, though, the scarcity of asteroid material in usefully shaped, workable, undamaged pieces could easily make it more valuable than any mineral content. Artworks made from materials that few people have ever seen before would not sell at the market price of their mineral content. Mass produced sample retrieval missions could at least offset some of their cost while getting material to test industrial processes on.

It's clear that djellison just refuses to even acknowledge any of the approaches that could actually make it feasible. All his arguments presume one-shot missions with NASA style system development, operations, and budgets, all equipment and material being launched from Earth, and a narrow minded focus on short term profits from material brought to Earth's surface. That's not a feasible approach, no. That's also not how anyone seriously proposing orbital industry thinks it'll be done, and it's foolish to continue arguing on that basis.

[cjameshuff]

That seemed counter intuitive to me too. So; I looked up the various Delta-V's to understand why.
So; please correct me if I'm wrong. (I'm getting numbers from wiki)
First; I guess I wasn't clear by what they meant by rendezvous. Now; I see it means landing.
So; that makes sense now.
To "reach" the moon (as in free return) you just need to get past EML1 (3.77)so the moon's gravity well exceeds that of earth. That's where my confusion came in. It's easer to "reach" the moon than an asteroid, but not to rendezvous with it.
What I still don't understand is why Earth escape is less than EML1.

EML1 is an orbit, not a location. You not only have to reach that point in space, you need to make a maneuver at that location to get yourself moving in the right direction at the right speed so you stay there. Due to the Oberth effect, taking that final delta-v at EML1 and applying it deeper in Earth's gravity well is more than enough to push you into an escape trajectory.

This is also part of why Phobos is cheap to access. You only need to brake into an orbit around Mars, which is considerably cheaper than braking to a stationary position with respect to a Phobos-sized body in Mars' place would be. That you can use aerobraking for part of this is just icing on the cake.

However, this is all delta-v cost. There are other costs...it takes months at best to travel between Mars and Earth, and due to the similarity in orbital periods, opportunities for minimum-energy transfers are spaced about 2 years apart. And you can't remotely operate or monitor equipment in real time, there's 4-20 minutes of lightspeed lag between there and Earth depending on relative orbital position. The moon can be reached in days, launching practically any time desired. Near Earth asteroids are even worse than Mars/Phobos in terms of frequency of launch opportunities, and for most of their orbit will be as bad in terms of lightspeed lag, which is why you want to capture them in Earth or Lunar orbit.

[Glom]

Centrifugal gravity requires very large spacecraft in order for it to work.

Is the 6 km/s figure for landing on the Moon or just entering Lunar orbit?

[Warren Platts]

Not that manned missions are necessary, but the gravity "problem" was solved long before we got anything into orbit. We don't need anything more than centrifugal gravity.

Anyway, if they can set up a volatile-harvesting operation in orbit, that opens up a huge variety of opportunities. Resupply, orbital tug services, etc. Much of the cost of putting anything in orbit is delta-v, the cost of delta-v is largely propellant, and being able to extract propellant from orbital sources instead of lifting it out of Earth's gravity well on low-Isp high-thrust rockets would be a major benefit. As we do things now, launching to LEO is about half the cost of launching to geosynchronous orbits...with cheap propellant in orbit, a tug service hauling satellites from LEO to GSO could turn quite a profit while reducing the cost of those satellites, while reducing insurance costs by reducing the risk of the satellite getting stranded in the wrong orbit. They could even sell slots on geosynchronous orbital busses that provide power, stationkeeping, backup communications, and regular access by robotic servicing missions, vastly reducing the complexity and risk of putting hardware in orbit...all ultimately resulting from availability of volatiles from orbital sources. There's numerous large potential markets in orbit just waiting for someone to come along and provide goods and services.

Returning large quantities of anything to Earth is a very long term goal, but it's also not remotely as expensive as sending mass in the other direction. One approach...shape a crude iron shell, possibly give it some minimal heat shielding, stuff your payload inside if it's not embedded in the iron itself, and drop it off with a tug. Once you have enough infrastructure set up in orbit, the only continuing cost is propellant...which once again, does not have to be launched from Earth.

That requires a fair bit of infrastructure for processing in orbit, which will take time and money to put in place...but these people are explicitly not looking for a short term profit. In the early stages, though, the scarcity of asteroid material in usefully shaped, workable, undamaged pieces could easily make it more valuable than any mineral content. Artworks made from materials that few people have ever seen before would not sell at the market price of their mineral content. Mass produced sample retrieval missions could at least offset some of their cost while getting material to test industrial processes on.

It's clear that djellison just refuses to even acknowledge any of the approaches that could actually make it feasible. All his arguments presume one-shot missions with NASA style system development, operations, and budgets, all equipment and material being launched from Earth, and a narrow minded focus on short term profits from material brought to Earth's surface. That's not a feasible approach, no. That's also not how anyone seriously proposing orbital industry thinks it'll be done, and it's foolish to continue arguing on that basis.

You guys really don't get it. I don't mean that in a bad way, but Ellison is correct. Nobody is going to be making a dime off of matter extracted from asteroids anytime soon. As in decades, if not centuries.

What they are going for initially is Earth imaging (a.k.a. "spying") (worth on the order of $10B/year) and then with the laser satellite networking tech they've got in their back pocket, they're going to go for the satellite communications market itself (worth on the order of $100B+/year).

Currently, the satellite business globally is worth around $160B/year, and it's growing at a fast rate. Believe me, these guys are not interested in barely breaking even by selling $5B/year of Pt. They are smarter than that....

[ravens_cry]

Until people start working on it, no one is going to make anything on Asteroid mining.
Ever.
Technology doesn't just pop out of thin air.
Even if it isn't practical now, the technologies to make it so are not going to invent themselves.

[cjameshuff]

Centrifugal gravity requires very large spacecraft in order for it to work.

No, it doesn't. It's perfectly doable with simple little capsules, you just need a tether and some sort of counterweight...like a chunk of asteroid.

Is the 6 km/s figure for landing on the Moon or just entering Lunar orbit?

There's separate entries in the table for low lunar orbit...4.04 km/s from LEO.

[Warren Platts]

They will be doing a lot of great philanthropy. They'll be leasing cheap telescope time to universities. They will be launching cheap "prospecting" missions to asteroids that will vastly increase our understanding of these enigmatic objects. They will be keeping a sharp weather eye out for dinosaur killers and city busters alike. If the nextbigfuture article is to be believed, they'll be able to generate 1-km resolution images of exoplanets around Alpha Centauri! 21st-century astronomy is heading for a major renaissance thanks to PRI!

What they will not be doing is asteroid mining. After they capture the $200B/year Earth satellite business and they're bigger than Exxon and Apple put together, then if they decide to do some real mining, they will go to the Moon. There, they can at least hope to dig up enough gold to make another $100B/year without crashing the price. The idea that they are hoping to make $5B/year selling platinum is stupid. These guys are not stupid.

[Garrison]

Until people start working on it, no one is going to make anything on Asteroid mining.
Ever.
Technology doesn't just pop out of thin air.
Even if it isn't practical now, the technologies to make it so are not going to invent themselves.

This is what I don't get with some of the responses to this plan. The threads about NASA and the SLS all tend to bring up the lack of ambition and vision in the current US space program. Here we have proposals that are all about ambition and vision and people are still complaining.

[Ilya]

This is what I don't get with some of the responses to this plan. The threads about NASA and the SLS all tend to bring up the lack of ambition and vision in the current US space program. Here we have proposals that are all about ambition and vision and people are still complaining.

Are they same people who complain about NASA's lack of vision? If not, then there is no contradiction.

[djellison]

This is what I don't get with some of the responses to this plan. The threads about NASA and the SLS all tend to bring up the lack of ambition and vision in the current US space program. Here we have proposals that are all about ambition and vision and people are still complaining.

There's a middle ground.

Something visionary, realistic, affordable and sustainable.

The only people even starting down that path, are SpaceX imho. NASA would go with them if Washington let them.

[Warren Platts]

I think what Planetary Resources will be doing is visionary (albeit, with dystopic, Orwellian aspects), realistic, affordable, and sustainable, (and potentially very profitable). It's just that asteroid mining is not what they will be doing.

[MaDeR]

SpaceX's quotes are already significantly lower, the Falcon 9H is expected to lift 6 times the payload of an Atlas 5 for the same price. Just because NASA couldn't do it in an economical way doesn't mean private industry also can't.

Promises does not count. I rely on what is now, not words about unspecified gains in future. Yes, future will change, but we cannot reliably predict that, for example, prices of launches will drop.

Yeah, but the best one on the list only has a 40% savings,

You "forgot" about gravity well of Moon. That makes two serious factors against Moon. Yest, there are things where Moon have advantage, like being close all time or having certain resources (ice - while asteroids have water too, it is harder to extract). In fact, I am for both using Moon and asteroids.

and what they don't tell you is that each one of those is "close" to the Earth for about 2 months out of every 20 years....

Assuming this is true average (no, I do not trust your figures without source), we can calculate, how much asteroids are in good place in given point of time. Two months out of 20 years is 1/240. This means in given month on average there will be about six suitable asteroids to launch to. Of course, not all of them will be attractive targets (both from delta-v and mineral standpoints) - but I expect on beginning they will take first easiest opportunites. Before any serious mining there will be long period of prospecting, bringing samples from various bodies etc.

Later thanks to prospecting we will know way, way more than 1500 asteroids easier to get to than moon, so best asteroids will happen very often. Orbital mechanics will allow for long time lead for any mission to specific asteroid with specific goals, planned for and prepared years in advance. Great number of asteroids will allow to select those that have very good times for reachnig, doing stuff* and returning it in short (relatively - few years) time.

It is how I understand it. I do not see anything outlandish in it. It all is very doable. Economy is issue, not tech. To be general, I do not see any mining - asteroid or moon - before prices for launching kg in space drops radically.

Nobody is going to be making a dime off of matter extracted from asteroids anytime soon. As in decades, if not centuries.

This is very funny to read, considering that you yourself have no less (in fact, way more) ludicrous proposals about *ahem* gold rush on the Wild West Moon.

In grand scale of things, looking from afar, asteroids and Moon are in same category. If mining asteroids are decades in future, mining Moon is also decades in future. One can start earlier than another, but by years, not decades or centuries.

* I am deliberately vague here. Mining, refining, preparing to return to Earth/space station/space ship, or making stuff in space or whatever.

[cjameshuff]

You "forgot" about gravity well of Moon. That makes two serious factors against Moon. Yest, there are things where Moon have advantage, like being close all time or having certain resources (ice - while asteroids have water too, it is harder to extract). In fact, I am for both using Moon and asteroids.

The gravity well of the moon is really only a major issue for landing equipment (or people, not that it's necessary for mining), and once a minimum of infrastructure is in place, there's several things that could be done to make soft-landing equipment easier...guide beacons for precision landings and prepared landing sites with soft, level ground and airbags, for example. For launch, a centrifugal sling could get most of the way to lunar orbital velocity if not beyond without any propellant use, and lunar linear mass drivers are quite feasible once sufficient industry is in place.

It is how I understand it. I do not see anything outlandish in it. It all is very doable. Economy is issue, not tech. To be general, I do not see any mining - asteroid or moon - before prices for launching kg in space drops radically.

You're missing the point in going after volatiles. The high cost in launching mass from Earth is exactly why mining volatiles in orbit can be profitable! Orbital tugs using propellants from orbital sources can roughly double the payload to geosynchronous orbit, allow multiple payloads on a single launch to be sent to different orbits, etc...the launch system need only get to low orbit, and it needn't even be one high enough to be stable for years. You could charge tens of millions for use of a tug and still save your customer tens of millions in launch and insurance costs. And that's just delivery, there's also things like deployment services...a craft with a couple robot arms could perform tasks like removing protective covers and solar panel deployment or perform installation in one of the shared orbital busses I mentioned in a previous post, simplifying development, reducing the amount of hardware you need to launch, and again reducing insurance costs. All made possible by the availability of cheap propellant in orbit.

[djellison]

All made possible by the availability of cheap propellant in orbit.

Define cheap.

Cheap, in terms of putting stuff into orbit is now about $2,000/kg

Even if we skip straight to the $1B/round trip asteroid collection - you would have to be pulling back 500 tons of propellant straight to LEO just to break even.

A GEO comms or weather sat is typically $500M.

The launch could be as little as $50M.

Having on-orbit rendezvous, tugs, refueling, etc etc etc - that's adding huge complexity (and thus cost) that are totally negated when launch costs are actually, not that much of the total mission cost anymore. Removing protective covers and deploying solar arrays? Spacecraft do that right now, with off the shelf parts that are really quite reliable already.

In essence, you're trying to argue that the difference in performance between LEO and GTO for launch vehicles is enough to warrant billions of dollars of investment in BEO mining? Sorry - it just doesn't add up.

[cjameshuff]

Define cheap.

Cheaper than lifting it from Earth.

Cheap, in terms of putting stuff into orbit is now about $2,000/kg

Even if we skip straight to the $1B/round trip asteroid collection - you would have to be pulling back 500 tons of propellant straight to LEO just to break even.

Why stop at a few hundred tons? Apart from it skewing the numbers in your favor.

A GEO comms or weather sat is typically $500M.

The launch could be as little as $50M.

Yes, around $50 million for, say, a Falcon 9 launch. Just going to LEO doubles the payload available...you can launch a whole other payload, halving the launch costs. The cost of the satellite itself is likely to drop even more than that due to the reduction of risk and complexity, the access to on-orbit servicing, etc. We're talking about simplifying a great many things and adding a wide variety of new capabilities, the only added complexity is a rendezvous with a tug that performs such operations routinely.

[Antice]

I think I'm on board with warren on this one. they won't be mining any asteroids anytime soon. they are after that juicy, low hanging fruit in the form of the satellite market. If their plan with the standardized mass produced and mass launched satellites work out, they will be making truckloads of money, then as icing on the cake they may very well go for some philanthropy by lending out observation time to universities and whatever else they want to do with their by then huge constellation of eyes and ears in the sky. Just by making orbital sensing cheaper they will be opening up new markets potentially worth hundreds of billions of dollars annually. imagine being able to online order a fresh satellite photo of your house for cheap. I mean who wouldn't? right.
I know farmers who pay good money to aircraft pilots just to get some half decent survey data from above their fields. Now imagine if they could get high fidelity growth measurements from orbit for cheap. They will buy it if it helps their productivity. (hoofing it trough the fields to measure growth rates is a big pita imho).

There are endless opportunities, in an almost endless market as long as satellite time can be sold cheaply enough.

[djellison]

Why stop at a few hundred tons?

Because a few hundred tons is the figure proposed by Planetary Resources to be returned by their design for an ion engined tug that would cost around $2.6B to develop and $1B per mission thereafter. Bigger mass couldn't be returned by that vehicle, it would require something larger, and more expensive.

Apart from it skewing the numbers in your favor.

Numbers from Planetary Resources lead engineer. if they're skewed...it's by them - not me.

The cost of the satellite itself is likely to drop even more than that due to the reduction of risk and complexity, the access to on-orbit servicing, etc.

On-Orbit servicing INCREASES complexity and risk.

We're talking about simplifying a great many things and adding a wide variety of new capabilities, the only added complexity is a rendezvous with a tug that performs such operations routinely.

That's a total contradiction. It's not simplifying - it's adding un-necessary complexity in an attempt to justify a program of BEO mining that simply doesn't close financially. You're adding extra processes, requirements, mechanisms, dependencies, and all of those add cost, complexity and failure modes.

[marsbug]

Actually, ores are refined above the ground, but near the mining site. Fish are, in fact, processed at sea: https://en.wikipedia.org/wiki/Factory_ship

Think about it this way. There is a marginal cost involved in transporting the ore. If you move processing closer to the mining site, you save on transportation costs, because you don't transport the noninteresting fraction -- which comprises the majority of the mined ore. Here's a real world example: copper ore mined in Poland contains 1.5 - 3% Cu. The ore is then refined on-site to 20-30% and only then shipped to the copper mill. Oil is the exception here, because virtually all fractions of the crude oil are usable, so there is nothing to be saved on transportation costs by refining on-site.

In space, where transportation cost is everything, there is even more reason to move processing close to the source. If your 500 ton asteroid contains 0.1% of Pt (i.e. 0.5 tons), then it makes much more sense to refine on site to 20% concentration and return 2.5 tons instead of 500 tons of unprocessed ore. That means all the platinum from a single asteroid could be returned in one SpaceX Dragon (rated downward payload 3'000kg). Since it is much easier to refine to 20% then it is to refine to 99.99% (which is what the final customer wants), it would make sense to do initial (easy) refining / separation on site, and only return the processed 20% concentrate to Earth for further processing.

No, I don't think I explained myself very well:
The fish are in the sea, and the factory ship on the surface. The ore is in the ground, and the refinary on the surface. The crude is underground, the processing on the surface. This is because the cost of moving the raw material to the surface (an easy-to-operate-in-environment) is negligable compared to the cost of moving the processing underground (a very-hard-to-operate-in-environment).

The relevent costs are the costs of transporting 'ore' to the surface VS the costs of moving and operateing the refinary away from it.

If the same logic applies to space, a hard environemnt to work in and very expensive to get a refinary into, then it will make more sense, for <10meter objects at least, to bring the raw materials to Earth to be processed.

Edit: Moving things to Earths surface is a downhill process. There is a nice thick atmosphere here to use for braking, and we don't need to worry about a chunk of ore having a rough landing. The costs of changing the objects orbit are the costs of deploying and operateing and maintaining the hardware, which is relatively quite simplistic next to an in space refinary.
Solar sails do not need fuel, sunlight for photovoltaics is abundant. We would need a disposable package to control the rocks final entry path as well I suspect.End edit.

Now I don't know what the costs of developing, building, launching, and operateing a system for getting a 10 meter Earth crosser to drop into a pre-selected patch of wilderness will be. Or the cost of getting the good stuff out.
Still I'd bet £10 that it will be at least a decade less than the one off and recurring costs of developing, building, launching, maintaining and operateing an in space-refinary.

Edit: I think I would go out on a limb and say that getting material resources from space won't close financially until we have eliminated as much of the need to put hardware for it into space, and certainly BEO, as possible. It's the transport costs to space, and the development, operation, and maintainence costs for a hugely complex machines in space, that are killers.

If some one could develop a cheap, solar powered, ground (or maybe LEO) based, system that made chunks of metal rich asteroid drop out of the sky into a known retrieval area (with a refinary just beyond one edge) then the financial case might just close. My handwavy guess is, anyway.

Planetary resources are doing this the Apollo way, and their goal is not profitability (short to medium term at least), so the above does not apply to them, but it does apply to anyone looking to actually make money off asteroid resources before 2040.

[cjameshuff]

Because a few hundred tons is the figure proposed by Planetary Resources to be returned by their design for an ion engined tug that would cost around $2.6B to develop and $1B per mission thereafter. Bigger mass couldn't be returned by that vehicle, it would require something larger, and more expensive.

You're still stubbornly assuming all hardware that gets sent up is used once and thrown away, replaced by more hardware sent up from Earth. That's just plain stupid, and clearly shows you're not even trying to see how it might work, but just setting up a straw man to ridicule.

On-Orbit servicing INCREASES complexity and risk.

That's a total contradiction. It's not simplifying - it's adding un-necessary complexity in an attempt to justify a program of BEO mining that simply doesn't close financially. You're adding extra processes, requirements, mechanisms, dependencies, and all of those add cost, complexity and failure modes.

I see. Reducing the number of tasks the hardware is required to do and using tried and tested hardware that routinely performs the needed operations, with the option of completely swapping out things like propulsive hardware in event of failure, results in an increase in complexity and risk.

Utterly ridiculous. You're not even trying any more.