It is a mission that might prove impossible. In the fall of 2020, a NASA spacecraft called OSIRIS-REx attempts to reach out and grab a piece of an asteroid named Bennu and bring it back to Earth. The OSIRIS-REx team has just three chances to extend its spacecraft’s specialized arm, touch down for five seconds, and collect material from the surface of Bennu. Can they pull it off? NOVA takes you inside the mission as the team plans its approach: They must map the asteroid’s surface, choose possible collection sites, and rehearse the risky maneuver. If the collection is successful, scientists could gain great insight into Earth’s own origins—and even learn to defend against rogue asteroids that may one day threaten our planet.