Green technology, which generates energy from renewable sources, has never been in greater demand. But there is an environmental cost to producing wind turbines, batteries for electric vehicles or solar panels.
The extraction of materials, known as rare earth elements, that are needed to build green technology has inflicted some of the worst ecological damage on our planet. Mining can leave behind toxic waste, cause soil erosion and water contamination and displace whole communities.
Why not turn to a source that contains billions of dollars of mineral wealth and can be extracted without harming Earth?
That is the question being asked by scientists and engineers who believe mining asteroids could be the way forward.
Minerals in asteroids can be far more concentrated than on Earth.
Asteroids are small chunks of rock and metal in our solar system. We know of about a million asteroids, which range in size from a few meters across to ones larger than 1,000 kilometers in diameter.
Most asteroids orbit between Mars and Jupiter. But others come closer to Earth, within easy reach of spacecraft that can extract their rich content. Their valuable minerals can be hundreds of times more concentrated than on Earth.
The mineral elements on asteroids include gold, silver, platinum, iridium, osmium, palladium, rhenium, rhodium, ruthenium, tungsten and many more. These minerals are crucial for green technology, smartphones, medicine and aerospace due to their durable, malleable and conductive properties.
Asteroids are the “low hanging fruit of the solar system,” according to Chris Lewicki, a former flight director at NASA’s Jet Propulsion Laboratory. Lewicki co-founded Planetary Resources, which focuses on developing robotic asteroid mining.
There have already been a number of missions to asteroids, including the Japanese Space Agency Hayabusa mission, which landed on asteroid Ryugu and returned to Earth with a sample.
The cost of space travel has fallen by a factor of three in the past half century, and the technology for building robotic craft to mine space resources already exists. Mining robots would need to heat up asteroid material, separate out the desired elements and then return to Earth with their payload.
Mining asteroids can produce far less CO2.
But which asteroids contain valuable minerals?
From Earth, we can use spectral images to discover if an asteroid has an abundance of valuable elements. The James Webb Space Telescope has increased that ability as it carries instruments that use wave lengths unavailable from Earth to analyse the surface of asteroids as well as planets.
What is the environmental cost of moving toxic mining activities off-planet? After all, launching rockets is not without cost.
Andreas Hein, a scientist and professor specialising in “disruptive future space systems,” has done the number crunching. Hein said that mining a kilo of platinum on Earth creates 40,000 kg of the greenhouse gas CO2. But mining a kilo from an asteroid will only create 150 kg of CO2, he said.
Hein is a professor at the University of Luxembourg, based in the tiny and wealthy nation that has a space agency focused on space mining. The Luxembourg Space Agency states that their goal is a sustainable space economy based on natural resources available on asteroids as well as the moon and Mars.
“Use of space resources will create major socio-economic benefits for humankind,” according to the agency. Luxembourg has attracted more than 70 space companies that have invested in this space mining potential.
When will the first robotic mining craft return to Earth?
Luxembourg is not alone in betting on the future of space mining.
Degrees in space resources are offered at the Colorado School of Mines. It’s an exciting but challenging field, according to Professor Jamal Rostami from the department of Mining Engineering. “The design of mining operations in space requires some out-of-the-box thinking and emphasis on automation, safety and remote operation,” he said.
The number of students opting for space resource studies may well rise when NASA’s Psyche mission launches in 2023.
Psyche is a rare, all-metal asteroid the size of a city that is estimated to contain elements worth in excess of $700 quintillion dollars — that’s 700 followed by 27 zeros. The Psyche mission is a purely scientific mission that will enable an array of instruments to beam back information on the composition of an asteroid that is not only valuable in monetary terms but in what it might reveal about the early solar system.
When will the first robotic mining craft return to Earth with a valuable payload?
Some scientists say possibly in the early 2030s, but technological leaps can speed up progress. After all, when in 1903 the Wright brothers achieved the first powered flight, which lasted a mere 12 seconds, they might not have believed that man would walk on the moon just 63 years later.