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Ask HN: What holds back asteroid mining?

16 points by xupybd ↗ HN
There is a a private space race going on but it seems space tourism, satellite deployment and contracting for space agencies are the only goals. Is it not yet possible to make money gathering resources in space?

Do we currently lack the technology or the precedent for profitable asteroid mining?

14 comments

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mdorazio
See Planetary Resources [1] for an example company working on this already. Bottom line: we might theoretically have the technology to make this happen, but realistically it would take decades and many billions of dollars to get an asteroid safely into earth orbit and put a mining station on it. There are a lot of challenges that need to be overcome (launch cost, spacecraft design, anchoring to an asteroid, stopping its rotation, bringing enough delta-v to get it moving, steering it into the right orbit, stopping it in the right orbit, mining in micro gravity, refining the mined materials in orbit, delivering materials from orbit to the ground or establishing in-orbit manufacturing, etc.) before it would actually be practical. Also note that current targets are actually near-earth asteroids, not the asteroid belt ones you're probably thinking of.

Side note: if you haven't already, I highly recommend playing Kerbal Space Program for a while to get an intuitive understanding of the challenges of space industry. It's really fantastic for learning about orbital mechanics, the tyranny of delta-v requirements, and challenges of in-orbit docking maneuvers. It even has some missions where you can try to capture an asteroid.

[1] https://www.planetaryresources.com/

rmtech
> delivering materials from orbit to the ground

As far as I am aware, there is no material that is expensive enough that it's worth the cost of moving it from space to earth. Even pure gold from space would be a loss.

mdorazio
Supposedly relatively pure platinum might do it. Note that if you're already in orbit, getting things to the ground is a pain, but not necessarily super expensive. For example, old spy satellites used to basically de-orbit their film, which was then picked up by airplanes [1]. The problem in this case is getting your asteroid into a nice orbit, then getting valuable chunks (instead of just regolith) off it, wrapped up, and on a nice return trajectory to the ground.

[1] https://en.wikipedia.org/wiki/Corona_(satellite)

rmtech
> relatively pure platinum might do it

the question for that is how much you would have to get to cover your fixed costs.

Still, deorbiting stuff in a controlled way is going to require something to be sent up - some reentry vehicle. And getting the reentry vehicle up there is expensive. If that reentry vehicle gets used up it will certainly wipe out your profit. 1 ton of platinum is $25,000,000... but a reentry vehicle plus launch costs is definitely more expensive than that.

Maybe some modern day space shuttle system that was fully reusable would work. Perhaps it could be a revenue generator for SpaceX's Starship on the way back from Mars?

mdorazio
Check your launch costs - they've come down a lot since SpaceX got their rockets going. You can get a reusable Falcon 9 for about $60M and it'll put 5.5 metric tons in geostationary transfer orbit, or significantly more mass in your choice of low earth orbit. A return capsule for metal/rocks pretty much just needs to be a heat shield on the front of a dumpster with some parachutes, so not very heavy. And an imperial ton of platinum would only be roughly half a cubic meter (surprisingly small, but platinum is dense), so volume isn't exactly an issue, either.

If you had the asteroid in orbit already and in-orbit mining + refining, getting the metals back down would be profitable.

rmtech
> A return capsule for metal/rocks pretty much just needs to be a heat shield on the front of a dumpster with some parachutes, so not very heavy.

The problem is that "just" a cargo return capsule would still be very expensive because everything in aerospace is very expensive. And there would be fixed costs running into many millions.

I think if the scale of the operation was big you could turn a profit at current prices. But a large scale operation would affect the price.

Also having a lump of platinum conveniently parked in LEO is kind of easy mode. If you have to get from somewhere then you're looking at an interplanetary mission, and the cost goes way up.

Again it would be profitable at scale... but the price would be affected. At some point I think there's a crossover.

lelabo_42
What if we don't mine asteroids in space? We just change their courses and make them crash on earth. There is a lot of math to be done and we might have to pick an international location as a crashing ground, but it should be easiest and more profitable.
jobigoud
What happens when a private company makes an error and causes a catastrophe, like an asteroid crashing on a city? The only precedent of that scale I can think of are Nuclear plants accidents. Usually the cost is shared by everyone, even by the people who opposed that particular technology exactly due to these risks.

When a private company takes risks that could negatively impact non customers economically, I feel some of this risk should be reflected in the price, or in taxes, in order to create an accident fund. In many cases this would make the adventure non competitive.

nitePhyyre
So you spend 20 billion dollars to bring back trillions of dollars worth of gold. What have you really done?

Spent 20 billion dollars to make gold worthless. That's not a good investment.

rmtech
I think what holds it back is that our space infrastructure sucks. To mine stuff - even really expensive stuff - and still turn a profit, it has to be sufficiently cheap to do all the mundane things like get the equipment into space, repair the equipment when it breaks, get the product back to earth.

All of that stuff is currently so eye-wateringly expensive that you could park a big pile of gold bullion on the moon and it would be safe from thieves because it would cost more to go and get it (per kg) than the gold is worth. Someone on Quora estimated that sample return from Mars costs about $1,000,000/kg using current tech[1], another estimate says $1,200,000/kg to the lunar surface[2]. No bulk material that I know of is that expensive. Platinum is $25,000/kg for example.

Another issue is that if you mined a small amount of gold/platinum/whatever in space, you might make a profit per kg, but you wouldn't cover the huge fixed costs of operating a company in space. If you mine a very large amount (tens of thousands of tons), you would negatively impact the price of expensive materials, reducing your profit per kg (perhaps enough that you were making a slight loss per kg). Even news of a serious effort to mine stuff in space would dent the prices of what was going to be mined. I think this latter argument is sometimes overplayed though. At some price level the price would stabilise even with greater production because these materials are quite useful as well as being visually attractive and traditional stores of value.

Better space infrastructure around earth could be as simple as SpaceX making reusable rockets work properly and reducing the cost per kg to get into low earth orbit. That could kickstart a lot of other developments like LEO (low earth orbit) space hotels, spinning space stations, in-orbit assembly. This would actually provide a nice market for asteroid mining - materials like water and metals could be put to use in space without coming back down to earth. We could have a thriving economy in LEO and MEO, supplied both from the surface and from trips to asteroids (some of which are not very far in delta-v terms from LEO)

1: https://www.quora.com/How-much-would-landing-and-returning-o... 2: https://space.stackexchange.com/questions/4720/what-is-the-m...

ryacko
I've read that for every order of magnitude increase in price, available reserves of minerals triples. It seems more likely that space colonies will export intellectual property than mineral wealth, especially since even if we get space elevators, Earth has all we need, especially as mines become automated.
rmtech
At some point it will be worth it to mine asteroids and bring the stuff back down to earth. I think that point will be when the scale of the mining is absolutely huge, and the infrastructure is amazing, and the price of the stuff we're mining (gold, platinum, etc) is substantially lower than what it is today.

It all comes down to whether you can get stuff from LEO to earth and earth to LEO really cheaply. If you can do that, then our economy will go grab this stuff and someone will make a lot of money doing it.

> space colonies will export intellectual property

Not for a long time though. Earth will have an advantage at making IP for a very long time. People will do research in nice places on earth rather than in cramped & dangerous conditions in space. The exception is microgravity research, but that's already a thing. Of course as the cost to LEO goes down we will do more of it. Eventually someone will commoditize it and you will be able to ship a container of a certain size with your low-gravity experiment to LEO for a fixed fee.

ryacko
Space is only cramped to minimize surface area, if inflatable habitats or some other form of assembly was used, structures can and will be much larger.

Sending materials to Earth will cost as much as sending them into space, as the materials must land safely and be recovered as efficiently as possible.

rmtech
> Sending materials to Earth will cost as much as sending them into space, as the materials must land safely and be recovered as efficiently as possible.

that's not true because the journey from space to earth has an aerobrake option, but the journey up requires a rocket with a certain amount of energy per kg you want to send.

In a large scale operation I think you could send stuff down relatively cheaply. A lot of effort would go into making a really mass-efficient reentry vehicle.

Another thing that would probably end up happening is a reentry bolo - a spinning tether that would subtract a huge amount of velocity from things going down.