# Plans for asteroid mining

#### Ryan_m_b

Staff Emeritus
Some materials (namely those of the Pt-group) would be returned to earth. Others would remain in space for application to structure or as fuel or as water.

The idea of mining asteroids and the moon has been around for decades, and there are numerous symposia and reports on the subject.
What I understood from the press conference is that the mining will concentrate mostly on (a) water, which is intended to stay in space, and (b) minerals that are extremely rare on Earth but presumed frequent on asteroids, i.e. platinum; for the latter, it was mentioned that it is one of the few materials which cost more than the price to put them in orbit. It doesn't sound like large volumes need to be brought back to Earth for the business to be profitable.

Edit: Astronuc just got ahead of me. :)
One wonders why mining sites of asteroid impacts doesn't get quite so much attention. It would also be interesting to see where the Moon factors into this, it's a lot closer and also has minerals rare on Earth. Though public campaigns against Moon mining would probably be greater than that of asteroids.

#### Astronuc

Staff Emeritus
One wonders why mining sites of asteroid impacts doesn't get quite so much attention. It would also be interesting to see where the Moon factors into this, it's a lot closer and also has minerals rare on Earth. Though public campaigns against Moon mining would probably be greater than that of asteroids.
Certainly places like Sudbury (a large nickel deposit) are well known. It's Pt-Rh-Pd and associated elements that are rather rare and are of most interest.

These folks have been interested in the subject of a long time.
http://www.planetary.org/home/
http://www.lpi.usra.edu/

The subject has been considered at symposia such as the Symposium on Space Nuclear Power and Propulsion and successor programs, e.g., STAIF and NETS, as well as AIAA meetings and others. Somewhere I have one of the older reports.

Back in the 1980s there was a NASA/USRA program to support graduate students in reviewing and possibly reviving the work done from the 1950s through 1970s in various areas of aerospace and nuclear technology. Part of that was looking at new technologies to realize things like colonizing the moon, mining asteroids and missions to Mars.

#### russ_watters

Mentor
Indeed, have you seen some of the timescales floating around?

Not only that but apparently the budget is only in the range of millions. Considering the long development struggle that private companies have had even to launch to LEO such figures are optimistic to the point of stupidity.
These people are not stupid, so what are the other possibilities?

These numbers simply may not be serius. They may be a publicity stunt designed to see if they can scare-up some investing.

#### russ_watters

Mentor
What I understood from the press conference is that the mining will concentrate mostly on (a) water, which is intended to stay in space, and (b) minerals that are extremely rare on Earth but presumed frequent on asteroids, i.e. platinum; for the latter, it was mentioned that it is one of the few materials which cost more than the price to put them in orbit. It doesn't sound like large volumes need to be brought back to Earth for the business to be profitable.
What do you consider "large volumes"? Platinum and gold are worth about $25,000/lb. If they can put$10 billion into development and spend $10,000/lb to recover it, it would take 666,667 lb to break even. And I consider those numbers absurdly optomistic. #### Ryan_m_b Staff Emeritus Science Advisor These people are not stupid, so what are the other possibilities? These numbers simply may not be serius. They may be a publicity stunt designed to see if they can scare-up some investing. Probably a combination of PR for show and to gauge the feedback from investors. What do you consider "large volumes"? Platinum and gold are worth about$25,000/lb. If they can put $10 billion into development and spend$10,000/lb to recover it, it would take 666,667 lb to break even.

And I consider those numbers absurdly optomistic.
A bit of googling tells me that 666,667lbs is nearly 5 times global annual consumption. Even if they did achieve that the flooding of the market would most likely massively deflate the value.

#### D H

Staff Emeritus
It would also be interesting to see where the Moon factors into this, it's a lot closer and also has minerals rare on Earth.
It's much more expensive in terms of Δv to go to the surface of the Moon than to go to the surface of a near-Earth asteroid. It's similar much more expensive to come back from the surface of the Moon than from to the surface of a NEO.

The Moon can factor in, however. It can make the trip to and from a NEO even cheaper if the vehicle steals some momentum from the moon via a gravitational slingshot. Using the Moon in this way could make the required Δv to the NEO less than Earth escape velocity.

Though public campaigns against Moon mining would probably be greater than that of asteroids.
Yeah. That fragile environment of the Moon needs to be protected.

#### Ryan_m_b

Staff Emeritus
It's much more expensive in terms of Δv to go to the surface of the Moon than to go to the surface of a near-Earth asteroid.
Ah cool, good to know
Yeah. That fragile environment of the Moon needs to be protected.
It's not a case of environment, Antarctica has a fairly sparse ecosystem but it's a global reserve. There was a debate at my undergraduate university about the exploitation of space and there was a strong movement for keeping the Moon in a similar state. I'm not saying I agree but highlighting the issue.

#### NeoDevin

Many of the investors in this project are not looking for an ROI in the next few decades. Larry Page and Eric Schmidt have a history of investing in projects because he thinks they are exciting, of benefit to society, and may pay off in the long run (see: automatic cars for example). James Cameron recently financed his own trip to the Marianas Trench. Charles Simonyi is a repeat space tourist. All of these people have a history of spending huge amounts of money on things they think are exciting, beneficial for humanity/science, and/or have a small chance of paying off huge in the long run.

One of the founders, Peter Diamandis, founded the X Prize foundation. Both founders, Diamandis and Eric Anderson, are aerospace engineers and founded the company Space Adventures. They have experience making money from space technology (I believe Space Adventures has been profitable so far, but can't find any details).

Further, all the calculations earlier in the thread assume only one source of income. Their first intention is to 'produce' water (and probably other chemicals, maybe they can find a source of fuel) in space for other (government) space programs, to save them having to bring their own. This alone may be profitable in the long run, though probably not a very good ROI. Following that they intend to mine for stuff to return to Earth. If they intended to make their entire ROI from mining platinum, as pointed out above, they would flood the market and drive down the price, and it wouldn't work. However, there are other rare minerals that can be mined as well. It may be possible to produce net profit without flooding any particular market, especially when combined with the sale of water and other chemicals to other space programs.

All of that is in addition to the fact that they get patents on all the technologies they develop along the way. Robotics, automation, aerospace, mining, telescopes, maybe some radiation shielding. Any of these technologies can have more immediate applications here on Earth. They can either spin off other companies along the way, or license the technology to other companies. Given that virtually every technology that needs to be developed for asteroid mining has direct and immediate applications in existing markets, it could end up being profitable even if they never bring back so much as a drop of water.

In summary: I think it's likely that this will work, in the sense that they will eventually bring something back from an asteroid. They have enough money behind it, from people who are not averse to risky, long term investments in exciting new technologies, and enough different avenues for producing revenue for it to work. That's not to say that the investors won't lose a lot of money in the process (or possibly just make less than they would in other more conventional investments), but they all have the money to lose.

My only concern is with the company name, Planetary Resources: It sounds just vague enough to be straight out of a distopian sci-fi movies. Kind of like Umbrella Corporation, Omni Consumer Products, Buy 'N Large, or the Soylent Corporation.

#### Higgs Boson

Reality check for asteroid miners ...

http://cosmiclog.msnbc.msn.com/_news/2012/04/24/11375462-reality-check-for-asteroid-miners?lite [Broken]

But hey! Their website is already up and running - at least that's a start ...

http://www.planetaryresources.com/

Excerpted quote from the MSNBC article linked above:

"There's a significant probability that we may fail," company co-chairman Eric Anderson acknowledged during today's big reveal at Seattle's Museum of Flight.

At least two things are certain: Planetary Resources is already bringing in income, and it's intending to launch real hardware within two years. "This company is not about paper studies. .... We're not just talking about it. We've done enough of that," Anderson said.

Last edited by a moderator:

#### Arch2008

The trick is to create an industry to do this as you go. We already know how to launch spacecraft to NEO. Build a small fleet of more efficient Shuttle 2.0 craft and pay for the trips by carrying commercial satellites to orbit. The first missions also carry the modules of a modest space station where the deep space vehicles will be assembled by crewmembers. The space station could also have a space tourism hotel module to pay for itself. The booster pods for the now defunct shuttles were perfect for these kinds of constructs but were foolishly allowed to burn up upon re-entry. So the bottom line start up cost is relatively low and doesn’t require any new technology.

Next, a simple group of automated probes go do a recon of which asteroids you should mine first. This survey would then be followed by a larger probe that nudges the target asteroid into NEO where the raw materials are extracted. The probe could use pellets made from material on the asteroid itself and shot out of a rail-gun on the probe to provide the thrust. A solar sail could deploy the probe to the asteroid, so once again, low cost and existing tech. Silicon from the Moon can be fused in solar powered kilns on the space station to make ceramic re-entry tiles. A simple re-entry pod could be constructed in orbit and used once per cargo load sent to Earth. The tiles might even be sold as souvenirs, since they were “Moon rocks”. As the asteroid u-haul process gains momentum, more ambitious programs could be funded. Once it starts, there’s really no reason to stop at one trillion dollars. A ten mile diameter nickel-iron asteroid has more ore on it than has been mined on Earth in all of history.

Spaceward ho!

#### D H

Staff Emeritus
A ten mile diameter nickel-iron asteroid has more ore on it than has been mined on Earth in all of history.
The subject of this thread, Planetary Resources, is not talking about mining nickel or iron. Mining nickel or iron simply is not feasible yet, and won't be for a long, long time.

This thread (and this site) is not the place for fanciful scifi dreams.

#### Ryan_m_b

Staff Emeritus
This thread (and this site) is not the place for fanciful scifi dreams.
AKA near-verbatim reiterations of the Mars Trilogy

Last edited:

#### Higgs Boson

The subject of this thread, Planetary Resources, is not talking about mining nickel or iron. Mining nickel or iron simply is not feasible yet, and won't be for a long, long time.

This thread (and this site) is not the place for fanciful scifi dreams.
Sooooo ... exercising one's imagination is verboten around here, these days, Delta Hotel?

#### redrum419_7

Sooooo ... exercising one's imagination is verboten around here, these days, Delta Hotel?
Apparently so.

#### Ryan_m_b

Staff Emeritus
Sooooo ... exercising one's imagination is verboten around here, these days, Delta Hotel?
Apparently so.
Of course not, speculation and imagination are welcomed. So long as they stay within the rules. Arch's post would have been acceptable if he backed anything he said up with some actual science to validate his points rather than just wishy-washy SF claims. For example: what are the potential candidates for a space shuttle replacement and is there a business argument for their production? Could a single space tourist module on a small space station pay for the program? What are the energy costs of propelling large fuel tankers to space and how are they suitable for space craft construction? etc etc etc.

#### lpetrich

Asteroid mining? Seems like a nonstarter. I seriously suspect that there won't be much by way of ore deposits in the asteroid belt, because of the lack of geological activity in most asteroids. To see why, let's review how how ore bodies form. Geologists have now gotten a good understanding of that, and we can use that understanding to see what one can expect of elsewhere.

Ore genesis - Wikipedia
Processes of Ore Formation
• Fractional crystallization of magma bodies.
• Sorting of immiscible components of magma bodies.
• Hydrothermal processes: water dissolving some minerals in hotter rocks and those minerals precipitating out in cooler rocks.
• Diffusion of minerals into cracks and the like ("lateral secretion").
• Precipitation from bodies of water, like salt being left behind when water evaporates.
• Mechanical sorting.
• Being left behind by other materials getting leached away by water flowing through.
• Release by volcanoes.
Most of these processes require liquid water, and only the Earth and Mars have such processes near their surfaces. There is even some evidence of such processes on Mars, in the form of evidence of carbonates and sulfates.

So we are stuck with igneous processes, rock melting. By the square-cube law, only a relatively large object can have such processes, so have any asteroids had them? The evidence, surprisingly, is yes. Certain meteorites, the "HED meteorites", have spectra similar to Vesta's surface, meaning that they likely came from Vesta.

So the smaller asteroids are unlikely to contain useful ores, except perhaps if they are fragments of some larger one that had had magma differentiation.

One could get the rarer elements by chewing through large quantities of asteroid, but it would be cheaper to do that with Earth rocks or seawater. But there *might* be some elements where mining asteroids might be worthwhile: the rarer "siderophiles". These are elements with a chemical affinity for iron, like gold and the platinum-group elements. The Earth's crust is depleted in them relative to stony and especially to iron asteroids, so one could mine gold by chewing through some iron asteroids.
Goldschmidt classification - Wikipedia
Mineralogy Notes 3
Abundances of the elements 3.1.3

#### Aidyan

But would it not be less costly to mine a very small asteroid (say only few dozens of meters wide) ON Earth than mining it in space? One has to de-orbit it, splash it into the ocean and retrive it. Then we can mine it easily at home. Obviously safety is the big issue here, if it wrongly hits a city it is a disaster. But I think atmospheric reentry is a complex but not impossible science.

#### D H

Staff Emeritus
But would it not be less costly to mine a very small asteroid (say only few dozens of meters wide) ON Earth than mining it in space? One has to de-orbit it, splash it into the ocean and retrive it.

No. Nobody sane is discussing the concept of de-orbiting an asteroid. Think about it.

#### SHISHKABOB

basically: you'd need A LOT of energy to take something going many km/s and slow it down to zero along with the energy needed to compensate for gravitational potential energy

it'd be silly

#### thorium1010

No. Nobody sane is discussing the concept of de-orbiting an asteroid. Think about it.
It maybe a silly/insane question .why is it impossible to bring small asteroids back to earth?
would it destabilise the asteroid belt or we cannot control the velocity it enters earths atmosphere. Or the energy required is too great for it to viable.

#### SHISHKABOB

It maybe a silly/insane question .why is it impossible to bring small asteroids back to earth?
would it destabilise the asteroid belt or we cannot control the velocity it enters earths atmosphere. Or the energy required is too great for it to viable.
it's because you're talking about taking a GIGANTIC ROCK from *space* to the *ground* without it just crashing and blowing some stuff up

we don't even have our spacecraft re-enter the atmosphere at slow speeds. How do you suggest we give an asteroid a "soft landing"? It's a totally unpractical idea.

also: no it wouldn't destabilize the asteroid belt, the only thing stabilizing the asteroid belt is the sun

#### lpetrich

It's possible to work out the numbers -- soft-landing an asteroid is TOTALLY impractical. Let's see what one needs to do.

-

This asteroid will be accelerated by the Earth's gravity, and when it reaches the Earth's atmosphere, it will be traveling at a little over the Earth's escape velocity, about 11.2 km/s. How much propellant will one need to consume to soft-land it?

Over a century ago, Konstantin Tsiolkovsky showed how to find how much. His rocket equation, for initial mass mi, final mass mf, effective exhaust velocity ve, and velocity change v:

v = ve * log(mi/mf)

Relation to specific impulse: ve = Isp*gE, where Isp is the specific impulse, and gE is the acceleration of the Earth's gravity at its surface, about 9.81 m/s^2.

So to avoid consuming much more propellant than asteroid, the rocket must have an exhaust velocity more than the Earht's escape velocity.

-

The asteroid must be supported by the rocket engines as it makes its landing. That requires that the thrust be greater than (asteroid mass)*gE.

So for a thousand-ton asteroid, that requires a thrust of a million kilograms-force or 10 million newtons. Bigger asteroids require more thrust, of course. I won't get into English-system mass and force units.

-

So let's see what's available. Spacecraft propulsion - Wikipedia has a big compendium of numbers in its "Propulsion methods" table, and Wikipedia's articles on various rocket engines often list the engines' numbers.

The highest-thrust engines that have been successfully run are chemical-combustion ones, at 1 to 2 million newtons, and hydrogen-oxygen ones can get about 4.5 km/s of exhaust velocity. Ones with non-cryogenic propellants can get as much as 3 km/s. Because of the nature of their energy sources, it's difficult to get much more exhaust velocity than that.

So they are unsuitable.

One can get more energy per unit mass with nuclear reactions, and thus greater exhaust velocity, but there are problems here also. A nuclear reactor heating hydrogen can get around 9 km/s or thereabouts, which is still too low to be suitable. It cannot get much more than that without melting the reactor. Nuclear-bomb propulsion can get greater exhaust velocity, but it has certain other problems. Inertial confinement fusion would also get high exhaust velocity, but that mechanism has yet to produce energy breakeven in the lab.

So they are unsuitable also.

In contrast to these thermal systems, there are various nonthermal propulsion systems, like ion engines, that are in various stages of development. The Dawn spacecraft, currently at Vesta, has 3 ion engines, each with exhaust velocity 30 km/s and thrust 0.09 newtons. Most other nonthermal engines have similarly low thrust.

These are still more unsuitable ones.

So there's no way that soft landing an asteroid is going to work.

#### Higgs Boson

So there's no way that soft landing an asteroid is going to work.
Unless someone engineers a really big catcher's mitt.

(Sorry, had to throw a little humor in there.)

Seriously though, from what I have read it appears to me, (and this remains no less feasible imho), that their intention is to manipulate said asteroid into some sort of orbit where it may be mined in space.

It is pie in the sky scifi though, I agree.

#### Antiphon

It will take a Dutch metallurgical genius to solve this problem. Someone who loves goooooold.

#### Aidyan

Why making things complicate? De-orbit slightly a NEO asteroid between the Earth and the Sun so that it takes the path towards Venus (not much thrust needed for that), 'aereobrake' it in Venus' atmosphere such that inserts itself into a synchronous orbit with the Earth + a component for Venus-Earth orbit transferal, and then, once it reaches Earth (at zero orbital velocity) let the thing simply fall freely and splash somewhere in a safe place in the ocean. It would be something like a Tunguska event, but at thousands of miles away from any inhabitated region. Maybe there is a problem with a Tsunami wave, but I think that if the asteroid is not too big, it will not harm. So, why not?

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving