Asteroid mining could be real with these tiny spacecraft

Scientists have come up with a new plan for asteroid mining and it involves launching a squadron of cereal box-sized robots at a nearby asteroid to detect the presence of precious metals.

The NASA-funded MIDEA concept project (short for Meteoroid Impact Detection for Exploration of Asteroids) was proposed at the fall meeting of the American Geophysical Union in San Francisco by Nicolas Lee, researcher at Stanford University’s Department of Aeronautics and Astronautics.

Asteroid mining is a tantalizing prospect. Platinum, gold, palladium and even plain old water are all embedded in these space rocks hurtling across the solar system. But before we can set up a mining camp on a Near Earth Object and start digging, we need to know which nearby asteroid and which kinds of asteroids are worth the mission.

One approach to gathering such information is now being studied, which involves sending a small fleet of tiny robot detectors to measure vaporized and ionized plasma given off by the asteroid as it gets hit by smaller space particles. Meteoroids are found throughout the solar system, and these little rocks collide with bigger rocks like asteroids at a surprisingly constant rate – about one mini-collision every ten days for every square metre of an asteroid’s surface, according to estimates.

“The material excavated from an asteroid surface by a meteoroid impact includes solid and molten ejecta, but some of this material is vaporized and ionized, forming a plasma that expands into the environment around the asteroid,” say Lee and colleague Sigrid Close, associate professor of aeronautics and astronautics at Stanford, in their concept proposal. “The plasma can be detected by a low-power electrostatic probe at a range of up to several hundred meters.”

The MIDEA project would send out so-called mother ships about the size of cereal boxes which would release five to ten free-flying plasma detectors once in range of an asteroid. These detectors would then sit in wait for the next meteoroid strike and measure the ionic discharge, thereby providing clues as to the types of minerals and their quantities on the asteroid.

“In about two weeks, we should get enough impacts to get an idea of [the composition of] the entire surface,” says Lee to space.com. Lee and Close estimate one of these mother ships could be build for between $10 and $20 million USD, vastly cheaper than most space exploration missions.

The researchers are currently focusing on the technology needed for the plasma detectors, while Lee projects that a MIDEA-based mission is still probably ten years away, with a trip into orbit around the Earth being the first step. “I think a LEO [low-Earth orbit] mission would be a good proof of concept,” Lee said. “That would make a lot of sense.”

NASA is currently pursuing a different approach to studying asteroids up close: its OSIRIS-REx spacecraft is now en route to the asteroid Bennu which it will meet up with in 2018. The mission involves hovering the spacecraft close to the surface of Bennu and sending down a robotic arm to the asteroid’s surface which, blowing a burst of nitrogen gas onto Bennu, will then collect materials for the ship to bring back to Earth (scheduled to arrive in 2023). The mission involves a complete and close-up mapping of Bennu, made possible by a laser altimeter provided by the Canadian Space Agency.

The OSIRIS-REx mission aims to learn more about the origins of our solar system from data and material gathered from Bennu and will aid in figuring out how we might one day divert asteroids like Bennu from crashing into Earth. NASA has other asteroid missions in the works, including one planned to visit 16 Psyche, a giant metal-rich rock in the asteroid belt between Mars and Jupiter.