ASTEROID MINING & KEY MEASURES
PURPOSE
Based on known terrestrial reserves, and growing consumption in both developed and developing countries, key elements needed for modern industry and food production could be exhausted on Earth within 50 to 60 years. These include phosphorus, antimony, zinc, tin, lead, indium, silver, gold and copper. In response, it has been suggested that platinum, cobalt and other valuable elements from asteroids may be mined and sent to Earth for profit, used to build solar-power satellites and space habitats, and water processed from ice to refuel orbiting propellant depots.
Although asteroids and Earth accreted from the same starting materials, Earth's relatively stronger gravity pulled all heavy siderophilic (iron-loving) elements into its core during its molten youth more than four billion years ago. This left the crust depleted of such valuable elements until a rain of asteroid impacts re-infused the depleted crust with metals like gold, cobalt, iron, manganese, molybdenum, nickel, osmium, palladium, platinum, rhenium, rhodium, ruthenium and tungsten (some flow from core to surface does occur, e.g. at the Bushveld Igneous Complex, a famously rich source of platinum, Today, these metals are mined from Earth's crust, and they are essential for economic and technological progress. Hence, the geologic history of Earth may very well set the stage for a future of asteroid mining.
In 2006, the Keck Observatory announced that the binary Jupiter trojan 617 Patroclus, and possibly large numbers of other Jupiter trojans, are likely extinct comets and consist largely of water ice. Similarly, Jupiter-family comets, and possibly near-Earth asteroids that are extinct comets, might also provide water. The process of in-situ resource utilization—using materials native to space for propellant, thermal management, tankage, radiation shielding, and other high-mass components of space infrastructure—could lead to radical reductions in its cost. Although whether these cost reductions could be achieved, and if achieved would offset the enormous infrastructure investment required, is unknown.
Ice would satisfy one of two necessary conditions to enable "human expansion into the Solar System" (the ultimate goal for human space flight proposed by the 2009 "Augustine Commission" Review of United States Human Space Flight Plans Committee): physical sustainability and economic sustainability.
From the astrobiological perspective, asteroid prospecting could provide scientific data for the search for extraterrestrial intelligence (SETI). Some astrophysicists have suggested that if advanced extraterrestrial civilizations employed asteroid mining long ago, the hallmarks of these activities might be detectable.
MINING CONSIDERATION
Three options for mining:
- Bring raw asteroidal material to Earth for use.
- Process it on-site to bring back only processed materials, and perhaps produce propellant for the return trip.
- Transport the asteroid to a safe orbit around the Moon or Earth or to the ISS. This can hypothetically allow for most materials to be used and not wasted.
Extraction techniques
Surface MININGS
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.
Self-replicating machines
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.
Proposed mining projects
Being the largest body in the asteroid belt, Ceres could become the main base and transport hub for future asteroid mining infrastructure, allowing mineral resources to be transported to Mars, the Moon, and Earth. Because of its small escape velocity combined with large amounts of water ice, it also could serve as a source of water, fuel, and oxygen for ships going through and beyond the asteroid belt. Transportation from Mars or the Moon to Ceres would be even more energy-efficient than transportation from Earth to the Moon.
Currently, the quality of the ore and the consequent cost and mass of equipment required to extract it are unknown and can only be speculated. Some economic analyses indicate that the cost of returning asteroidal materials to Earth far outweighs their market value, and that asteroid mining will not attract private investment at current commodity prices and space transportation costs.Other studies suggest large profit by using solar power.Potential markets for materials can be identified and profit generated if extraction cost is brought down. For example, the delivery of multiple tonnes of water to low Earth orbit for rocket fuel preparation for space tourism could generate a significant profit if space tourism itself proves profitable.
There are six categories of cost considered for an asteroid mining venture:
- Research and development costs
- Exploration and prospecting costs
- Construction and infrastructure development costs
- Operational and engineering costs
- Environmental costs
- Time cost
In February 2016, the Government of Luxembourg announced that it would attempt to "jump-start an industrial sector to mine asteroid resources in space" by, among other things, creating a "legal framework" and regulatory incentives for companies involved in the industry. By June 2016, it announced that it would "invest more than US$200 million in research, technology demonstration, and in the direct purchase of equity in companies relocating to Luxembourg." In 2017, it became the "first European country to pass a law conferring to companies the ownership of any resources they extract from space", and remained active in advancing space resource public policy in 2018.
In 2017, Japan, Portugal, and the UAE entered into cooperation agreements with Luxembourg for mining operations in celestial bodies.
Ongoing and planned
- Hayabusa2 – ongoing JAXA asteroid sample return mission (arrived at the target in 2018)
- OSIRIS-REx – ongoing NASA asteroid sample return mission (launched in September 2016)
- Fobos-Grunt 2 – proposed Roskosmos sample return mission to Phobos (launch in 2024)
- VIPER rover — planned to prospect for lunar resources in 2022.
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| HRITHIK SHAH hrithikshah000@gmail.com |
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