▲ Donald Brownlee , Stardust principal investigator with the University of Washington , flashes a victory sign for the successful arrival of Stardust material . Also pictured are JSC ’ s Mike Zolensky ( left ), curator and coinvestigator for the project ; Friedrich Horz , JSC , and Peter Tsou , Jet Propulsion Laboratory . Credit : NASA

our ability to detect valuable metals in those asteroids

The dust was successfully returned to Earth . The material collected resulted in some valuable scientific discoveries ; but grabbing a few tiny micron-sized particles is a long way from industrial-scale mining .

The Japan Aerospace Exploration Agency ( JAXA ) has executed the most successful missions to retrieve material from asteroids so far . While the Hayabusa 1 mission to 25143 Itokawa asteroid encountered difficulties and was only able to return with some dust particles , the Hayabusa 2 mission is currently underway to explore and sample the NEA , 162173 Ryugu .

The probe was launched carrying three small rovers , a landing module , and equipment for taking surface samples . It has already completed two sampling runs , where it blasted the asteroid with a tantalum projectile then collected the flying debris . Hayabusa 2 is expected to return home in December of 2020 and the samples it carries will be the largest payload of samples retrieved from a near-Earth body since the Apollo missions .

NASA also has ongoing missions to take samples from NEAs . The OSIRIS-REx probe is currently orbiting an NEA , Bennu , where it will map the surface and retrieve samples .

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