Asteroid Mining (Script) (Patreon)

Quietly on January first, 2009, a company called Arkyd Astronautics was formed; a secretive organization with a cryptic name and plans with ties to billionaires like X-Prize founder Peter Diamandis and James Cameron. In 2012 they revealed their plan to the world. That company, now named Planetary Resources, was on a mission to mine asteroids for their precious resources and perhaps save the planet along the way.

The richest person in modern history, was John Davison Rockefeller, His net worth was three times greater than that of our richest tech billionaires, inflation adjusted. And the source of that fortune? Timely exploitation of a vast, then-untapped natural resource: oil. Well, the days of oil may be numbered, but there’s another natural resource that’s never been touched, is effectively inexhaustible, and has a dollar value large enough to disrupt entire economies. That resource? Asteroids, and the precious materials they contain. Astrophysicist Neil deGrasse Tyson predicts that the world’s first trillionaire will be an asteroid miner. The Rockefellers of the 21st century may be less like the internet and tech moguls of the 20th century and more like the old-school oil barons of the 19th.

But asteroid mining isn’t the same as drilling a hole and hoping black gold spurts out. It will take years of work by dedicated engineers and scientists and billions of dollars to extract the first dollar’s worth of useful asteroid material. So will it happen? CAN it happen? To answer this question, we need to learn a bit about asteroids.

Asteroids, along with comets, are leftover material from the formation of the solar system. They range from a meter or so to hundreds of kilometers in diameter, and live primarily in the asteroid belt between Mars and Jupiter. There are also a few smaller groups of asteroids inhabiting different regions and orbits or the inner solar system, include some that cross Earth’s orbit. As you’ll see, these will become important. 

Unlike the more icy comets of the outer solar system, asteroids are rocky or metallic. They are the stuff of the terrestrial planets - the building blocks of worlds like the Earth that never managed to pull themselves together. The most abundant asteroids are C-type, or carbonaceous asteroids, constituting three quarters of all known asteroids. They have a high abundance of water, an extremely valuable resource in space. I’ll explain why in a sec. C-type asteroids do contain some valuable heavy elements, but not as much as some other asteroid types. For example, S-type, or silicaceous asteroids. They make up roughly 17% of the asteroids and contain, you guessed it, silicates. They’re rocks. They contain more valuable elements than C-types - a good amount of iron and nickel and a smattering of more precious stuff that I’ll get back to. 

Third most abundant are M-type asteroids. That’s M for metallic. Most are big chunks of iron and nickel. These are the leftover cores of larger asteroids that were destroyed by collisions. If an asteroid is massive enough, it will undergo a process called differentiation. During its formation, when it’s still a giant ball of molten space rock, heavier iron and nickel will sink to an asteroid’s center. Smash that asteroid hard enough and you shatter it, exposing a juicy rich metallic core.

All asteroid types have the potential to be profitable. The key to that profitability is the right combination of valuable contents, mission-essential resources, and accessibility. Let’s start with the good stuff: What loot do asteroids drop? Well definitely gold and platinum and other precious metals. It’s not that there’s more of this stuff in asteroids than on Earth, it’s just that it’s more accessible. See, the same differentiation process that lead to M-type asteroids long ago sucked Earth’s crust dry of many elements. This is particularly true of elements that alloy readily with iron; they followed iron into the core or mantle during Earth’s formation. This includes gold, platinum and silver, but also key industrial metals like palladium, rhodium and iridium. These elements are just more accessible in all but the largest asteroids. In fact much of the precious metal content of Earth’s crust came from old asteroid impacts.

The Planetary Resources company estimates that a single 30-meter asteroid may contain 30 billion dollars in platinum alone, and that a 500-meter rock could contain half again the entire world reserves of platinum group metals. Kilometer-scale asteroids would be worth many trillions. It’s worth noting that the value some elements, like gold and platinum, are largely due to their rarity. Asteroid miners are going to have to be careful not to crash the value of these materials with over-supply.

Perhaps the most lucrative asteroid loot will be the stuff that’s useful to industry. That includes some of the aforementioned platinum-group elements but also the rare-earth elements. Both groups are essential in everything from electronic components, batteries and fuel cells, magnets, as chemical catalysts and reagents, and in a huge range of advanced materials. The technological world is utterly dependent on these elements, and becoming more so. While rare-earth elements aren’t actually all that rare in Earth’s crust, most are dispersed in a way that makes sifting them out is not commercially viable. Concentrated rare-earth mineral deposits exist, but those are genuinely rare and the accessible supply is running low. 

Asteroids are literal goldmines for stuff we want to bring back to Earth, but they also contain materials useful for the mining process itself. Raw materials like iron, nickel, aluminium, and titanium are not cost-effective to bring back to Earth, but can go towards building infrastructure in space, including more asteroid mining facilities. But even more important is water. Water dissociated into hydrogen and oxygen becomes rocket fuel, which is critical for shipping mined resources back to Earth. If you have to carry that return fuel on the initial launch vehicle, you have to massively cut back on the amount of mining equipment and you also limit what asteroids you can access.

The perfect asteroid has a decent amount of water, but also a high abundance of valuable materials. It also needs to be large enough to be worth the effort and accessible by an economical spacecraft. Eventually we’ll probably see mining operations in the actual asteroid belt, where useful rocks are plentiful, but to start with it’s much easier if the asteroid comes to us. Fortunately for asteroid miners - though less fortunately for the dinosaurs - many asteroids cross Earth’s orbit in their passage around the Sun. Some of these near-earth asteroids can be accessed with relatively little fuel expenditure from Earth orbit, and these will be the target of the first missions.

Identifying perfect “easily recoverable object” - or ERO is where a lot of the action is right now. This asteroid prospecting is the current focus of effort for Planetary Resources and its competitors. We know of over 17,000 near-earth asteroids, but only a small fraction are likely to be cheaply accessible, large enough, and have the right composition to be worth the effort. To be sure of a profitable composition, robotic prospectors are going to have to visit asteroids. Planetary Resources is developing its Arkyd spacecraft with that initial goal, and their main competitor, Deep Space Industries is working on a range of low-cost prospector craft. Interestingly, both companies have significant funding from the Grand Duchy of Luxembourg. Apparently this tiny land-locked nation has some impressive cosmic aspirations. 

So let’s say we find the right asteroid. Then what? Well we can attempt to mine it on location - so with the orbit of the asteroid - or we can nudge it into a more accessible orbit close to the Earth, perhaps even in orbit around the Moon. This can be done with a gravitational tractor which we talked about before, or with rockets fueled by the asteroid’s own water supply. Moving a near-earth asteroid to lunar orbit was the goal of NASA’s Asteroid Redirect Mission, but it was canceled in 2017 due to lack of congressional support. Shame really - it was one of the few missions that had a clear track to massive potential profits AND saving the planet from asteroid impact. Because if we learn to land and push an asteroid to a different course, we could potentially push an earth killing asteroid off course. 

OK, we found our asteroid and sent our mining facility. How do we harvest the goods? It could be a simple matter of scooping up rocky material from the surface. Smaller asteroids are expected to be loosely-bound rubble piles, so breaking them apart will be relatively easy. There are also proposals to scrape regolith - asteroid dust - from the surface, or to magnetically harvest loose surface metals. There’s also the Mond process, by which carbon monoxide gas reacts with iron and nickel to produce a gas containing these metals; this can then be collected and processed by the spacecraft. Water is the easiest to extract - it can simply be evaporated from the surface and collected as vapour. For larger, solid asteroids it may make sense to actually tunnel into their interiors, but that’s a way down the track.

The first asteroid mining missions are slated for the 2020s, but the timetables are very loose. Once the enterprise demonstrated to be profitable, you can be sure the real goldrush will begin. Money talks. Tens of billions, or even trillions of dollars per asteroid speaks very loudly. Perhaps in just a few decades we’ll have mining outposts in the asteroid belt. The first efforts will be purely robotic, but as the industry scales up in the asteroid belt, real live human operators may be needed. Who knows, perhaps Season 30 of The Expanse will be listed in drama instead of science fiction. And with that abundant supply of resources without the insane per-kilogram price tag of launch from Earth, perhaps the real work can begin, of expanding humanity’s reach into more distant regions of space time.