Space Mining: By the Numbers
~ the future is… HUGE ~
TL;DR — Whoever DOUBLES their equipment, turning it into more equipment quickly, will dictate what happens in space. So, how soon can we expect asteroids to industrialize? One century, before all those rocks are machines. After that, we’ll need to work-out an agreement — or there will be a war for who controls the planet Mercury, the Treasure-House of our solar system.
We Earthlings consume 4.5 Billion tons of concrete each year — that’s “4.5 times 10 to the 12th power” in Scientific Notation, which just means “4.5 with 12 zeroes behind it”. Compare concrete’s “10¹²kg per year” to the mass of the Asteroid Belt — some 2.4 times 10²¹kg. That is to say, if the Asteroid Belt were made of concrete, it’d supply humanity for 500,000,000 years. That’s 8x Dinosaurs-ago! It won’t last us anywhere near that long. Why? Doubling-time.
If we get 1 kiloton of machines into space, and they can turn themselves into another kiloton of machines after 2 years, look what happens: In 20 years, there have been ten doublings, for 1,024x the initial mass, or 1 Megaton. That’s still only 10⁹kg, tiny compared to concrete, right? 40 years of space-mining — another 1,000x, for 1 Gigaton in space. Okay… and 10²¹kg, that entire Asteroid Belt? Oh, it only takes 140 years. Gone.
“But, how could machines possibly double every two years? That seems fast…”
Factories in space, which pump-out robotic parts and assemble the builders for more robotic factories, mining equipment, can double VERY quickly. Let’s check some more big numbers…
Imagine a space-factory is melting asteroids using reflected sunlight, boiling metals away and condensing them on filters to be re-melted and pressed, rolled, cut by machines, assembled by robotic arms, and shot-out of coil-guns to the corners of the solar system. If that factory and associated mining rigs are able to process 1kg of material every second, then they will pump-out 86.4 tons every day, or 31.56 thousand tons each year. In two years, that’s about 63 Kt of output, which (using the good old “rule of 70”) implies that the factory and mining operations needed (63/.7)= 90 thousand tons of equipment!
To unpack that a bit: “If my space-factory and mining-operation weigh 90 thousands tons, total, (that 90 Kt is the “mass budget” of the factory-system) and it ONLY outputs 1kg per second, then yes, it is on-schedule to double in 2 years.” Similarly, if a factory-system weighed 9 Gigatons, it would need to expel 100 tons of material per second, in order to double in 2 years. I don’t expect the *initial* space-rigs to be anything like that; but the first mining operation to double quickly will completely overtake the rest.
“How much equipment would you really need, to process 1kg per second?”
The Sun God
Power is the first factor to consider. The sun provides an immense AND convenient power-source, which even *nuclear reactors* cannot match! This is because solar energy can be concentrated onto a point, to such intensity that any nuclear reactor would melt. And, solar energy is transported at the speed of light, without any equipment needed to carry it along its path! Most importantly, though, a single cubic yard of Mylar reflecting sunlight will provide more than twenty Megawatts of power, compared to a ten Megawatt nuclear reactor (with modern designs that are as tall as a people-pyramid and wider than a truck). That material efficiency is what sets solar reflectors above all others. “With the least equipment and materials, I can haul power-plants-worth of energy anywhere, at light-speed.”
Critically, that high power density allows a high throughput — each kg of equipment is pumping-out kilos of product quickly, because power concentrated.
So, we’ll be enveloping asteroids in bags, and using concentrated solar reflectors to boil the metals into a gas. That’s a lot less mass of equipment, compared to a steel foundry! That metal-gas will deposit on filters as it tries to escape and cools against surfaces. Robots will re-process those captured metals and minerals, rolling and shaping metal in all the familiar ways. Those steel rollers and presses are massive, unfortunately, and the metal-cutters only process a small amount of material per second. That sort of equipment & tooling is the primary mass-cost.
Yet, those are all familiar quantities in modern industry, and none of them approaches the “mass budget” from our space-factory math! 1kg per second is enough to double a factory that uses 90,000 tons of stuff, but the steel mills and assembly facilities on Earth doing all that same work use hundreds of tons of equipment per kg/sec throughput, not 90,000 tons! (It’s worth remembering that we can write-off most of the mass of Earthly *buildings* and *support* structures, because there is no apparent gravity to stress space-components.)
So, if asteroid mining can expect to double in less than two years, repeatedly, then we have a century before they’re all gone.
“What about the really BIG asteroids?”
Oh, we’ll nuke those. Next question?
The Planet Mercury…
The Asteroid Belt is actually really tiny — 4.5 x 10²¹kg compared to the planet Mercury’s 3.3 x 10²³kg. That is, Mercury is almost 100 times larger than ALL the asteroids, combined. What’s worse, only 8% of the asteroid material is valuable metals — 3.6 x 10²⁰kg, or just one thousandth of Mercury’s mass. Meanwhile, 85% of Mercury’s mass is it’s immense molten, metal-rich core. And, Mercury has the highest concentration of rare metals generally, which makes mining more effectual & lucrative, as well. Those metals are precious for electronics and chemical catalytics. And no other planet can get-at such quantities of them, so easily.
So, whoever can claim Mercury will have hundreds of times more precious metals, essential to technology, compared to everyone else combined. There’s an important dynamic that unfolds in these sorts of trade-environments:
If the Queen of Mercury wants Nitrogen, then there are 100 sellers, all gathering that element from various ice-moons and comets and dust clouds. Because Nitrogen can be found in many places, then there are many operations, and they compete by lowering prices. That ensures the Queen of Mercury gets a good deal on her Nitrogen! Same for carbon — three quarters of the asteroids are carbon-rich, so plenty of folks can stake their own claim, and they all compete by lowering prices. The Queen of Mercury can sell just a tiny bit of precious metals, to buy all the Carbon she needs!
This is because the Queen of Mercury has 95% of the Solar System’s recoverable Yttrium. Did anyone need that, for superconductors or catalysts? Oh, you did! Pay up. Same for Samarium. Osmium. Ruthenium. Keep going down the list. Mercury is the “Strategic Resource” that every major government will consider a “Primary National Interest”. Mercury is the LAST “new oil” until we get to another star in a millennium.
If we don’t have good, toothy policies in-place to handle the mad dash for Mercury, then we can expect the conflict over that planet to cause a war here on Earth. Mercury has such a concentration of precious resources, with so little available anywhere else, that it holds the solar system hostage. For that reason alone I recommend a neutral, equal-shareholder model — ALL of humanity profits, while the company operating the Mercury-mines earns a flat rate, forced to sell at modest margins, or blind auction. Mercury must be all of ours, or it will belong to only one.