In just a few hours, the world will know whether NASA’s OSIRIS-REx spacecraft successfully reached out and touched Bennu, a tiny, top-shaped asteroid that’s been spinning through the solar system for a billion years. During the maneuver, the spacecraft will swoop down, scoop up a bit of material, and depart seconds later with precious cargo: rocks and dust dating back to the solar system’s birth.
The mission is humankind’s third attempt—and NASA’s first—to sample the surface of an asteroid. The first two asteroid sampling missions, performed by Japan’s Hayabusa and Hayabusa2 spacecraft, picked up only small amounts of fine-grained material. By contrast, OSIRIS-REx is designed to pick up as much as 4.4 pounds of material that ranges in size from tiny grains to two-centimeter-wide pebbles.
Assuming all goes well, a radio dish in Spain will receive the signal that OSIRIS-REx completed its task at 6:12 p.m. ET on October 20.