Space mining

SPACE MINING

Asteroid mining is the exploitation of raw materials from asteroids and other minor planets, including near-Earth objects.
Hard rock minerals could be mined from an asteroid or a spent comet. Precious metals such as gold, silver, and platinum group metals could be transported back to Earth, whilst iron group metals and other common ones could be used for construction in space.
Difficulties include the high cost of spaceflight, unreliable identification of asteroids suitable for mining, and ore extraction challenges. Thus, terrestrial mining remains the only means of raw mineral acquisition used today. If space program funding, either public or private, dramatically increases, this situation may change as resources on Earth become increasingly scarce compared to demand and the full potentials of asteroid mining—and space exploration in general—are researched in greater detail.

EXTRACTION TECHNIQUES

Surface mining On some types of asteroids, material may be scraped off the surface using a scoop or auger, or for larger pieces, an "active grab. There is strong evidence that many asteroids consist of rubble piles, making this approach possible.

Shaft mining A mine can be dug into the asteroid, and the material extracted through the shaft. This requires precise knowledge to engineer accuracy of astro-location under the surface regolith and a transportation system to carry the desired ore to the processing facility.

Magnetic rakes Asteroids with a high metal content may be covered in loose grains that can be gathered by means of a magnet.

Heating For asteroids such as carbonaceous chondrites that contain hydrated minerals, water and other volatiles can be extracted simply by heating. A water extraction test in 2016 by Honeybee Robotics used asteroid regolith simulant developed by Deep Space Industries and the University of Central Florida to match the bulk mineralogy of a particular carbonaceous meteorite. Although the simulant was physically dry (i.e., it contained no water molecules adsorbed in the matrix of the rocky material), heating to about 510 °C released hydroxyl, which came out as substantial amounts of water vapor from the molecular structure of phyllosilicate clays and sulphur compounds. The vapor was condensed into liquid water filling the collection containers, demonstrating the feasibility of mining water from certain classes of physically dry asteroids. For volatile materials in extinct comets, heat can be used to melt and vaporize the matrix.

Extraction using the Mond process The nickel and iron of an iron rich asteroid could be extracted by the Mond process. This involves passing carbon monoxide over the asteroid at a temperature between 50 and 60 °C for nickel, higher for iron, and with high pressures and enclosed in materials that are resistant to the corrosive carbonyls. This forms the gases nickel tetracarbonyl and iron pentacarbonyl - then nickel and iron can be removed from the gas again at higher temperatures, perhaps in an attached printer, and platinum, gold etc. left as a residue.

Heating A 1980 NASA study entitled Advanced Automation for Space Missions proposed a complex automated factory on the Moon that would work over several years to build 80% of a copy of itself, the other 20% being imported from Earth since those more complex parts (like computer chips) would require a vastly larger supply chain to produce. Exponential growth of factories over many years could refine large amounts of lunar (or asteroidal) regolith. Since 1980 there has been major progress in miniaturization, nanotechnology, materials science, and additive manufacturing, so it may be possible to achieve 100% "closure" with a reasonably small mass of hardware, although these technology advancements are themselves enabled on Earth by expansion of the supply chain so it needs further study. A NASA study in 2012 proposed a "bootstrapping" approach to establish an in-space supply chain with 100% closure, suggesting it could be achieved in only two to four decades with low annual cost. A study in 2016 again claimed it is possible to complete in just a few decades because of ongoing advances in robotics, and it argued it will provide benefits back to the Earth including economic growth, environmental protection, and provision of clean energy while also providing humanity protection against existential threats

Companies and organizations Several organizations have said they are working on asteroid mining, including: