Mining metals on asteroids long ago stopped being a plot found only in science fiction novels. But skeptics ask a fair question: what will happen to prices for rare materials if someone actually brings them to Earth in industrial volumes? Two systems dynamics specialists from the Massachusetts Institute of Technology (MIT), Robert Nachtrub and Stephen Smith, tried to find the answer to this question. Their work, titled "Will AstroForge Crash the Platinum Group Metals Market?", is posted on the arXiv preprint server.
Platinum group metals (PGMs) are platinum, palladium and their "relatives". Modern industry is inconceivable without them: they are needed for automotive catalytic converters and hydrogen fuel cells. On Earth these metals are found rarely: more than 80% of known reserves are concentrated in deep mines in South Africa and Russia. Mining yields grams per ton of rock and requires heavy machinery, ventilation, cooling and the labor of miners underground. It is not surprising that PGM prices reach tens of millions of dollars per ton.
M-type metallic asteroids are another matter. They are fragments of the cores of protoplanets, and the concentration of PGMs in them is tens of times higher than in the richest terrestrial mines. A single kilometer-sized asteroid of this type contains more platinum and palladium than humanity has mined in its entire history. It is no accident that these objects have for decades attracted the attention of supporters of space mining.
The California startup AstroForge is one of the new players in this field. Instead of multibillion-dollar stations, the company builds small probes costing a few million dollars per launch. According to the concept, the craft attaches itself to a metallic asteroid with magnets, powerful lasers vaporize its crust, and an onboard plant separates PGM vapors from less valuable nickel and iron. The purified metals are sent to Earth in a capsule with thermal protection.
Nachtrub and Smith built a computer model that tracks how the PGM market will change over 20 years after the first successful delivery of cargo from an asteroid. According to the calculations, the market faces a two-phase transition. First a "space gold rush" will begin: PGM prices will for now remain at a high level because of the supply deficit, and the first companies will be able to sell the metal at enormous profit. According to the authors' estimate, industry profit during this period could grow eightfold compared with the current level. This will attract investment and increase space mining capacity.
Then the second phase will arrive: the "collapse of equilibrium". When PGM supply exceeds former terrestrial volumes, prices will fall sharply. The first to suffer will be expensive mines, for example in North America, and after them large mines in Russia and South Africa. According to the model, over 15 years space supplies will completely displace terrestrial mining, and market prices will fall by more than 75%.
For the mining industry this is bad news, but for everyone else it is good. Cheaper PGMs mean cheaper electrolyzers for producing hydrogen, and therefore the transition to a "green" economy will become less costly. Moreover, space mining brings no acid drainage, arsenic contamination or dangerous labor in deep shafts.
However, all this is only the result of modeling, not an accomplished fact. The authors emphasize that serious engineering problems stand in the way of such a future, and AstroForge has already had loud failures. Nevertheless, the company is approaching making asteroid metal mining a reality. And if this happens, all participants could become fabulously rich in less than two decades.