There's a reason that most meteors that enter the Earth's atmosphere explode before reaching the surface.

Plenty of spacecraft pieces, specifically spherical tanks coming down from can survive relatively intact, so you could specifically design for it. I actually looked if anyone had proposals for landing Shuttle ETs relatively intact and came across US4832288 and other wacky hypersonic drag device proposals, mostly inflatable. But for mined material starting in space, it doesn't need to be inflatable. If you can make thin sheet materials, then making a big stacked toroid blunted cone or tension cone would be feasible as well.

I think it is also worth investigating methods to bring high value raw material to the earths surface that are more brutish, yet possible more economical & within existing technological capability.

Here is my proposal:1. Baseline mass return is around 1000ton or less, which is in the ballpark of the Asteroid redirect mission profile.

2. Space mining will focus on precious metal initially. Returning low value metals like nickel & iron just may never be worth it, & they are probably worth more to use in space for building structures. This example will use platinum.

3. I think in space refining will need to separate the Pt from the bulk of the asteroid material. This is where the majority of operational cost will be.

4. Once separated & refined, it will be melted & formed into a slug/projectile. Some Ni/Fe may be utilized as sacrificial material on the blunt end, & as a casing for the Pt that will undergo entry heating as it encounters earths atmosphere.

5. A 1000 ton slug of Pt would be around 4.46 meter in diameter, if it was made spherical. Ideally I would make it cylindrical, with a Ni-Fe blunted nose. The value of the Pt metal is around $31 Billion USD ( around 7-8 years of annual planetary consumption of Pt )

6. Precision crash land it somewhere in the arctic ocean, where ocean depth is around 1000m, but basically within the capability for robotic retrieval equipment.

An object of this size entering the earths atmosphere at a 45 degree angle at 20 kps would likely survive entirely intact on the seafloor. ( I entered the parameters in this interesting model ) You could also separate the 1000 tons into multiple projectiles to customize the impact events to minimize material loss and environmental impact.http://impact.ese.ic.ac.uk/ImpactEffects/

So for $31 Billion USD sitting at a well defined location on the seafloor: A. Can technology be made to retrieve the metals for circulation into global Pt demand and still make money?B. Can a space mining company make and acceptable environmental impact arguments of conducting sub megaton impact events in an ocean vs. the impact of conventional mining?

I think it is also worth investigating methods to bring high value raw material to the earths surface that are more brutish, yet possible more economical & within existing technological capability.

Here is my proposal:1. Baseline mass return is around 1000ton or less, which is in the ballpark of the Asteroid redirect mission profile.

2. Space mining will focus on precious metal initially. Returning low value metals like nickel & iron just may never be worth it, & they are probably worth more to use in space for building structures. This example will use platinum.

3. I think in space refining will need to separate the Pt from the bulk of the asteroid material. This is where the majority of operational cost will be.

4. Once separated & refined, it will be melted & formed into a slug/projectile. Some Ni/Fe may be utilized as sacrificial material on the blunt end, & as a casing for the Pt that will undergo entry heating as it encounters earths atmosphere.

5. A 1000 ton slug of Pt would be around 4.46 meter in diameter, if it was made spherical. Ideally I would make it cylindrical, with a Ni-Fe blunted nose. The value of the Pt metal is around $31 Billion USD ( around 7-8 years of annual planetary consumption of Pt )

6. Precision crash land it somewhere in the arctic ocean, where ocean depth is around 1000m, but basically within the capability for robotic retrieval equipment.

An object of this size entering the earths atmosphere at a 45 degree angle at 20 kps would likely survive entirely intact on the seafloor. ( I entered the parameters in this interesting model ) You could also separate the 1000 tons into multiple projectiles to customize the impact events to minimize material loss and environmental impact.http://impact.ese.ic.ac.uk/ImpactEffects/

So for $31 Billion USD sitting at a well defined location on the seafloor: A. Can technology be made to retrieve the metals for circulation into global Pt demand and still make money?B. Can a space mining company make and acceptable environmental impact arguments of conducting sub megaton impact events in an ocean vs. the impact of conventional mining?

Seems plausible to me.

You're completely glossing over the biggest cost here -- extracting 1,000 tons of platinum from an asteroid in the first place.

The class of asteroids richest in platinum have around 30 parts per million of platinum. At the high end, they can go up to 63.8 parts per million:

Processing ore to extract such tiny concentrations requires a huge infrastructure. It would be incredibly expensive to set up and operate a plant in space to do that. Even on Earth, such plants require a lot of human labor to maintain, in addition to water, lubricants, and stocks of various chemicals. Doing that in space would not only require housing and supplying all those people but also finding ways to overcoming the challenges of doing it all in microgravity and vacuum.

The costs would quite clearly be much higher than the costs of extracting the same amount of platinum from mines on Earth. The somewhat higher concentrations of platinum in the ore would be more than offset by the enormous cost multiple of doing it all in space.

Someday, when we have millions of people already living in space, the costs of infrastructure off Earth will decline enough that it will become economically competitive to mine platinum from asteroids versus mines on the Earth's surface. We are very far from that day.

(mod)How is this on topic? Just advocating that we read it doesn't cut it. YOU need to edit your post (not reply) to provide the tie in that explains clearly why artificial photosynthesis is indeed on topic for an asteroid mining thread. Thanks.

Logged

"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

6. Precision crash land it somewhere in the arctic ocean, where ocean depth is around 1000m, but basically within the capability for robotic retrieval equipment.

Why an ocean impact?

When the projectile lands, there is still around 90% of the kinetic energy left, if it lands in water, that energy is primarily transferred to the liquid, if it impacts land, more energy transfer will go into the projectile, which will vaporize a significant portion of it. The rest will melt & scatter. So basically it preserves the valuable material better.

ChrisWilson68 is right that I glossed over the most difficult task, which would be to refine enough asteroid ore to get a purified slug of Pt massing hundreds of tons. That is the challenge those who want to mine asteroids will face. I think it only works out if you can refine the asteroid material in space, transporting low grade material to earth will be pointless. My response was targeted at just the problem of getting material to earths surface.

6. Precision crash land it somewhere in the arctic ocean, where ocean depth is around 1000m, but basically within the capability for robotic retrieval equipment.

Why an ocean impact?

When the projectile lands, there is still around 90% of the kinetic energy left,

How do you come to that conclusion? That re-entry only reduces velocity by 6 percent?

Actually my 90% remaining kinetic energy was based on using the model I linked to, however I erred in recalling figures for a larger impactor. For the 4.46m diameter projectile, the model says the KE is dropped to 70% just prior to impact. ( started with 1.96E14 Joules, & lost 5.95E13 joules in the atmosphere) http://impact.ese.ic.ac.uk/ImpactEffects/

Remember: kinetic energy scales to the square of velocity, so a 6% drop in velocity does not equal a 6% drop in KE.

Again, the point of this was to show if you can guide your returning slug of refined asteroid metal, you don't need a fancy entry scheme. Let it crash & recover it. The bigger problem is refining it in-situ.

But suppose you are with Goldman Sachs, & you set out a business plan to capture 80-90% of global platinum demand. You can meet this with one such event ( 4.5 meter sphere of Pt ) about once a decade. How many cycles of mine/refine/return to earth do you need to undertake to get a decent ROI?

I would suggest that by the time it is economical to refine platinum from asteroids we'll have large scale, reusable craft flying frequently between the Earth's surface and space. Think ITS flying weekly, at least. At that point, returning the platinum to the surface of the Earth is a non-issue -- we'll just carry it down on the ITS-scale ships that are flying regularly anyway. That will be cheaper than building some kind of heat shield around a giant slug of platinum then dredging it up from the bottom of a lake.

I would suggest that by the time it is economical to refine platinum from asteroids we'll have large scale, reusable craft flying frequently between the Earth's surface and space. Think ITS flying weekly, at least. At that point, returning the platinum to the surface of the Earth is a non-issue -- we'll just carry it down on the ITS-scale ships that are flying regularly anyway. That will be cheaper than building some kind of heat shield around a giant slug of platinum then dredging it up from the bottom of a lake.

Are you suggesting that ITS scale ships will match the orbit of asteroid ore shipments, or all ore shipments will be have to be placed into an earth orbit for pickup by a ITS ship? Sounds expensive in DV and propulsion hardware cycles. There's a lot of hand waving in that scenario.

It's also dismissive & unfounded to automatically assign high technical hurdles to something unknown. The "heat shield" could end up being incredibly simple if made of sacrificial nickel:iron. Assuming high complexity reminds me of when SpaceX signaled their intention to land rockets downrange at sea. Speculators were suggesting Musk should buy the SeaLaunch platform, or procure a decommissioned aircraft carrier, & other complicated bunk. What happened? He bought a cheap barge and welded some plate steel to the deck.

I would suggest that by the time it is economical to refine platinum from asteroids we'll have large scale, reusable craft flying frequently between the Earth's surface and space. Think ITS flying weekly, at least. At that point, returning the platinum to the surface of the Earth is a non-issue -- we'll just carry it down on the ITS-scale ships that are flying regularly anyway. That will be cheaper than building some kind of heat shield around a giant slug of platinum then dredging it up from the bottom of a lake.

Are you suggesting that ITS scale ships will match the orbit of asteroid ore shipments, or all ore shipments will be have to be placed into an earth orbit for pickup by a ITS ship?

No and no.

First of all, you're saying "ore" here, but the proposal I'm responding to is to refine the ore into a pure platinum and send it to Earth with a disposable heat shield made of asteroid material.

So, there has to be a serious ore processing plant creating the platinum. That ore processing plant will need lots of people to work at it, and lots of chemicals shipped in. In other words, a lot of logistics. Those logistics will by by ITS-scale ships. So, no orbit matching or anything like that. The pure platinum is produced in the same place that has lots of ITS-scale ships going back and forth to it. Simply carry the platinum there.

I have a different opinion than you. There's no need to start accusing me of hand waving and being dismissive. I don't believe there's justification for saying I'm automatically assigning a high technical hurdle. Everything is unknown here to a greater or lesser degree. We're all speculating. Obviously, each of us believes our opinions are the better founded. If we just start accusing each other of hand waving, where does that get us?

I'm not assuming anything. I'm offering speculation, just like you and everyone else on this thread. It's irritating to have someone label speculation they disagree with as "assuming" while in the same message that person does plenty of speculation of his own.

reminds me of when SpaceX signaled their intention to land rockets downrange at sea. Speculators were suggesting Musk should buy the SeaLaunch platform, or procure a decommissioned aircraft carrier, & other complicated bunk. What happened? He bought a cheap barge and welded some plate steel to the deck.

You think yours is the simpler, more obvious solution, and I think mine is the simpler, more obvious solution. Trying to tie yours in to Musk does nothing to prove your point.

My post in response to the thread topic was directed at just one part of the problem of asteroid mining, that being the return of the metal product to the market paying for it.

I invoked technology in the near same class as the asteroid redirect mission, i.e a SEP powered space tug capable of precisely hauling a 1000 tons of material to the vicinity of Earth/moon lagrange points. ( a pretty specific & precise target) That does not invoke Musk, it is agnostic to Musk & anyone else. It is also the technology invoked in Post #1 of this thread in the report from Goldman Sachs.

Waiting to mine asteroids until Musk/Bezos/ULA or whomever have fleets of ITS like ships crossing the inner solar system is invoking Musk & others, & it sets a "gate" as to the level of technology that needs to be in place to start mining asteroids. You have projected a good part of your assumptions onto mine.

You may actually be right on this issue, neither of us knows for sure how it will play out, if it ever does. That's fine with me. Like you, I come here to read, digest, & consider opinions of other people, including you. (ChrisWilson68)

So let me finish this post with my assumptions, as I try to examine them:1. Goldman Sachs would not be commenting on Asteroid wealth if they did not have their greedy little hearts & minds churning on how to make some money. I'm good with that!

2. Goldman Sachs, or other VC groups will try to make asteroid mining happen when they believe technology enables it, & they can get a good return on the investment risk.

3. The decision to mine asteroids will be agnostic to which technologies are used. However, like any economic enterprise, it will naturally pick the lowest cost technology to accomplish the task and maximize the return.

Number 2 & 3 open up a plethora of topics & avenues of discussion. We both probably agree that how valuable metal is returned to earth is the smallest of the problems. I'm more interested in how to extract & concentrate the metal, as well as ideas how to capture market share without crashing global prices.

... I'm more interested in how to extract & concentrate the metal, as well as ideas how to capture market share without crashing global prices.

The global annual supply of PGMs is worth around ~$12 billion at current prices, for roughly 500 tons of refined material ( palladium + platinum being around 45% + 45% of it ).

Nearly 70% of the total supply goes to automotive catalysts, with jewelry grabbing a second good slice.

If you don't want to crash the prices fast, the order of magnitude of operations cannot be very much larger than the current net demand is.

Mining development and construction projects on earth take a good 5 years to field, and the investments are in billions, but not in tens of billions range.

I think there are two possible models of development: aim to supply maybe 10-20% of the annual market, effectively creating another significant supply region besides South Africa and Russia, with the corresponding price drop. Still serving existing markets. It's tough to come up with feasible numbers for developing such a venture and seeing returns on a reasonable timescale.

Or, aim to increase the supply by some insane amount, like 5x current actual demand, crash prices and expect new demand and applications to emerge. They would have to be new, as there is simply no way jewelry and diesel engine catalysts will soak up that much even at drastically lower material prices. Unless such a new application is identified/mapped out, nobody will invest in this venture due to massive capital investment at insanely high risk.

Which i think basically comes back to - should space PGMs mining ever be developed, it won't be purely market driven, it'll need significant upfront public investment for R&D and risk reduction of related technologies. Most likely this investment can come from countries that are either resource scarce or see it as strategic value. China, maybe.

The global annual supply of PGMs is worth around ~$12 billion at current prices, for roughly 500 tons of refined material ( palladium + platinum being around 45% + 45% of it ).

Nearly 70% of the total supply goes to automotive catalysts, with jewelry grabbing a second good slice.

The majority going to automotive catalysts is a potential problem for asteroid mining profitability. By the time asteroid mining is operational, most cars will be electric. With lower demand, the price will drop, making it harder to justify asteroid mining.

... I'm more interested in how to extract & concentrate the metal, as well as ideas how to capture market share without crashing global prices.

edited & snipped...

I think there are two possible models of development: aim to supply maybe 10-20% of the annual market, effectively creating another significant supply region besides South Africa and Russia, with the corresponding price drop. Still serving existing markets. It's tough to come up with feasible numbers for developing such a venture and seeing returns on a reasonable timescale.

Or, aim to increase the supply by some insane amount, like 5x current actual demand, crash prices and expect new demand and applications to emerge. They would have to be new, as there is simply no way jewelry and diesel engine catalysts will soak up that much even at drastically lower material prices. Unless such a new application is identified/mapped out, nobody will invest in this venture due to massive capital investment at insanely high risk.

Which i think basically comes back to - should space PGMs mining ever be developed, it won't be purely market driven, it'll need significant upfront public investment for R&D and risk reduction of related technologies. Most likely this investment can come from countries that are either resource scarce or see it as strategic value. China, maybe.

I have been thinking it may be possible to drive the market for asteroid supplied PGM's through legislative means.

Treat the matter as we currently treat blood diamonds, or conflict minerals ( gold, tin, titanium, tungsten). Ammend the Frank-Dodd legislation to set deadlines for industries consuming PGM's to certify the supply chain. This can be approached with environmental justification, as well as potentially being a de-facto political sanction against states we are in conflict with ( hot or cold conflict, i.e Russia )

Or for improved efficiency one might mine and separate the PGMs and gold, and then load them as incidental cargo, all upon the same celestial body; e.g., Mars.

Ideally you'd want something like Omaha Crater's domes and hydroelectric power on the ground, plus the Omaha Trail's Mars Lift, propellant and rail launch in orbit, so as to increase efficiency even further, well past the point of winner-take-all market dominance.

A strategic rare-metal reserve would be a reasonable outcome.

Our press release, from a presentation given in conference last week at UNSW Sydney, OEMF2017: