NASA spacecraft begins 2-year trip home with asteroid rubble

A NASA spacecraft is headed back to Earth with rubble it collected from an asteroid nearly 200 million miles away

CAPE CANAVERAL, Fla. -- With rubble from an asteroid tucked inside, a NASA spacecraft fired its engines and began the long journey back to Earth on Monday, leaving the ancient space rock in its rearview mirror. The trip home for the robotic prospector, Osiris-Rex, will take two years. Osiris-Rex reached asteroid Bennu in 2018 and spent two years flying near and around it, before collecting rubble from the surface last fall. The University of Arizona’s Dante Lauretta, the principal scientist, estimates the spacecraft holds between a half pound and 1 pound (200 grams and 400 grams) of mostly bite-size chunks. Either way, it easily exceeds the target of at least 2 ounces (60 grams).