It is no surprise that when the prospect of asteroid mining is first mentioned it tends to draw blank stares, say at cocktail parties. "What? Asteroid mining? How would you do that?" Most people aren't even aware there were (at last count) some 792, 347 asteroids, most of which are in the Asteroid Belt. This is a vast, doughnut -shaped ring between the orbits of the planets Mars and Jupiter.
Most of the asteroids with mining potential are the "Near Earth Objects" (NEOs) - which have orbits that allow them to approach within 121 million miles of Earth - or about 28 million miles further than the Sun (the recent target for the Parker solar probe) is from Earth. Indeed, ten NEOs have come closer to the Earth than the Moon since 2004. (The closest such pass occurred on January 8, 2008, when such an object passed within 5, 441 miles of the surface.)
Naturally then, humans would wish to know how to extract raw materials from such invaders, and not merely see them as threats. See also:
Three Classes Of Asteroids - And The Resources The...
Remarkably, few earthlings are aware we've already been interacting with asteroids in different ways. For example, last March, the Japanese probe Hayabusa2 dropped an explosive on Ryugu - an NEO - and later scooped up a sample from the scattered debris. Meanwhile, NASA's Osirirs-Rex craft is preparing to land and collect a sample from the asteroid Bennu. (See graphic). This NEO is roughly 443 m in diameter and has been found to be ejecting rocks into space. One might say almost begging for resource extraction.
What sort of resources are we talking about and how might they be used? There are basically three distinct groups: Volatiles, Industrial metals, and Platinum group metals.
The volatiles include: hydrogen, carbon, nitrogen and oxygen. Such raw elements could easily be used to provide fuel, water and materials for space travel. As an example, a single asteroid like Bennu could produce $5 trillion worth of water to be used in space. (Such production in situ for spacecraft compares with the cost of $20,000 to send just one liter of water from Earth to deep space.).
The industrial metals include: iron, cobalt and nickel - which can be used in space for construction of space vehicles and platforms. Cobalt - which specific asteroids have up to 27 times more than on Earth - is also crucial for many digital electronic uses on our planet. For example, it is used widely for batteries and electroplating. Currently, child miners in Congo are used to extract the metal from deep pits. See e.g.
Children as young as seven mining cobalt used in ...
The platinum group of metals includes: Ruthenium (810 times more found in an asteroid than on Earth), Rhodium (180 times more), Palladium (44 times more), Iridium (540 times more) and Platinum ((196 times more). All of which can be transported back to Earth to support the production of a host of manufactured goods such as: LCD screens, catalytic converters, fuel cells, medicines and virtually all electronics. What scale are we talking about in terms of the actual materials that can be used?
Well, one single 500m platiunum rich asteroid could translate into $1.45 trillion worth of pure platinum. Or, for reference, 297 times more than the global production of this metal in 2017. (At current market prices one ounce of platinum is valued at about $800.)
If one thinks about it, the extraction of each type of resource (volatile, industrial metal, platinum metal) would require a different mode of mining. For example, to extract needed volatiles the design shown below could be used - say for a smallish ( ~ 2-3 m wide) NEO.
The harvesting of the volatiles can proceed when a specially- designed space vehicle is able to "bag" and heat the contained asteroid. This would be done using solar reflectors to boil off and then collect the raw elements (e.g. hydrogen, oxygen) in situ to sustain life in space and produce fuel.
In the case of industrial metals, it is envisaged (by the asteroid mining experts at Colorado School of Mines) that robot miners would be able to efficiently extract ample amounts of manganese, cobalt, molybdenum, nickel and titanium for construction of space structures.
For the platinum type metals, it is envisaged that appropriately designed space craft cold capture and transport the specific metal-rich asteroid into an orbit around the Moon. Once there, Moon -based miners could extract the needed contents, e.g. gold, palladium, rhodium, platinum etc.
Preposterous science fiction? Not really! Lockheed Martin has already signed on as the prime contractor for NASA's Orion - designed for deep space explorations as well as possible asteroid mining ventures. (The company has been working since the early 2000s on technologies to tap space resources.)
Meanwhile, in the fall of 2018 the Colorado School of Mines became the first university to offer masters and doctorate degrees in space resources. There, many student experiments are already underway designed to test mining capabilities such as described in this post.
Stay tuned!
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