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John S. Lewis On the Space Commodities Market
John S. Lewis -- Deep Space Industries' chief scientist, author, and University of Arizona professor -- speaks in an interview with Air & Space magazine about the practicalities and possibilities of deep-space mining, a topic on which he is unapologetically bullish. He points out, though, that some of the artist's-conception version of space mining skips over some of the economic realities of getting back to Earth metals that are scarce here. From the interview: But—and here’s the big conditional—if we develop an industrial capability in space such that we’re processing large amounts of metals to make solar-powered satellites, for example, then as a byproduct, we would have very substantial quantities of platinum-group metals, which are extremely valuable. So if you have a market for the iron and the nickel in space, that would liberate the precious metals to be brought back to Earth. So the scheme is not based on the idea of retrieving platinum-group metals—that is simply gravy."
One of the reasons metals from the Platinum Group are precious is that they're scarce. If we recover as much of those elements as he's talking about, they won't be scarce any longer, which means that they won't be that precious. Of course, that's not a bad thing because there are lots and lots of other uses for them besides jewelry.
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We don't, not without encasing the equipment in some sort of unobtanium hull to protect from the temperature and pressure. Mining at any depth on Earth is *hard*. The appeal of asteroid mining is that they appear to be conglomerations of relatively pure ores needing minimal refining to be useful - far easier (in principle) than refining Earth-based ores. It's only that pesky industry in a zero-G vacuum thing that we don't have any experience with slowing us down.
Asteroid mining isn't a question of not having resources on Earth - the combined mass of the entire asteroid belt is estimated at only 5% of that of the Moon. It's a question of having resources available outside a deep gravity well that will allow us to expand beyond our planet. As they said, the platinum and other "valuable" materials are just gravy that help make the early "bootstrapping" stages of development more economically appealing - it's primarily the bulk construction elements such as iron, silicon, carbon, etc. that are truly valuable in space.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
The thing is, to do anything in space you need propellant. Launching it from the ground is a mugs game; it costs ~$1000 per kg to get it even to LEO, even more to higher orbits.
No, if you can mine propellant, then you can get ROI on any propellant you can return to LEO (or higher orbits).
The thing is, we know for pretty high probability that (for example) Ceres has huge deposits of water.
You can split water into hydrogen and oxygen, and use that for propellant. Once you have propellant you can set up cyclers that take about 15 months to deliver a load to LEO, and then go back and get some more. The amount you return each time can potentially grow exponentially each time, because you're using propellant to deliver propellant/"mining" equipment.
The thing about Ceres, it looks like there's ice volcanos there, so "mining" water may be as simple as putting a funnel over the stream coming off Ceres, and bring it to a halt and pumping it into a tank. You can then use some of the water to send the rest of the water back towards Earth.
And water in LEO is TREMENDOUSLY useful. Want to go to the moon? You need propellant to go there. Want to go to Mars? You need propellant and radiation shielding. Guess what- what is brilliant radiation shield as well.
I'm not against other types of mining; but propellant mining is the one that all the other things rely on- it's the equivalent of oil in space.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"> The appeal of asteroid mining is that they appear to be conglomerations of relatively pure ores
For Platinum-group metals, relatively pure means ~15 ppm in asteroids. On Earth, the vast majority of these metals sank to the core, because they are "iron-loving" (mix well with Iron), and that's where the Iron went. Metallic asteroids are the result of protoplanets large enough to *also* develop iron cores, but later collisions broke them up and exposed the core bits, where you can reach them.
Nonetheless, when you do the math, 15 parts per million is frosting on the value of asteroid rock. Most of it is in the bulk elements you can use in space directly. Space is already a $323 billion industry, so there is a lot of value in not having to launch stuff at great expense.
> Unless you are able to use that material in space
That's the intent for early asteroid mining. Space industry is already $323 billion a year total, and a major consumable for all space missions (mostly satellites in Earth orbit) is fuel. Any future Lunar or Mars missions would add large demands for fuel to the existing traffic. But even just existing commercial satellites need fuel to get to their operating orbit and maintain position. If they run out of fuel, or parts break, the satellite has to be written off and replaced. A fuel depot and repair station would save billions a year. To run the depot you need a fuel supply, plus supplies for the repair crew. That's the first market for asteroid mining. Anything else will develop over time.
> Earth is where the money is.
Right. Communications, satellite TV and radio, GPS, weather, ground mapping. The money is down here, but the hardware is in orbit.
> but materials like iron
There is no shortage of iron on Earth. There's a shortage of iron in orbit, where it costs at least 3 times it's weight in silver to deliver. And so does anything else you want to put in orbit. Mining in space to use in space can retrieve 350 times the initial fuel load back to Earth orbit. As long as you find a use for a reasonable percentage of that returned mass, you win over launching it from Earth.
NEOs can have much lower deltav but have much worse Synodic periods. That's because the orbital periods are similar, and they take longer to line up each time. And for a near Hohmann transfer which most travel is likely to use, they have to line up.
So opportunities to travel there or back are few and far between. This makes them surprisingly useless as a propellant source, because unless the mining operation is unreasonably quick to perform, for orbital mechanics reasons you have to wait for multiple synodic periods before you return anything, and another one again before you can do it again. For example, if the synodic period is 5 years it could take 15-20 years to get your first shipment.
Ceres is further out, but its synodic period is only 466 days; so you end up with a propellant shipment every 466 days.
Getting to Ceres initially with mining gear is harder but a penalty that you only have to pay once, and you can use ion drives which can have high exhaust and deltav for that, but once you're returning propellant, you have the propellant you need to send further stuff to Ceres from Earth, and Earth to Ceres, so, although the deltav is the same each time, the effects of the delta-v penalty aren't quite so severe and you can set up cyclers to make the trip repeatedly at lower delta-v, and use aerobraking at Earth for the propellant.
The other thing is that Ceres is outside the snow line; most NEOs have probably been baked out of volatiles on their surface, so mining them is much harder. Ceres is further out, so ice evaporates very slowly.
All in all, Ceres looks like a much better bet all round.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"