NASA spacecraft touched down on the rugged surface of the Bennu asteroid on Tuesday, grabbing a sample of rocks dating back to the birth of our solar system to bring home. The minivan-sized OSIRIS-REx spacecraft, built by Lockheed Martin, extended its 3.35m robotic arm toward a flat patch of gravel near Bennu’s north pole and plucked the sample of rocks, the space agency's first handful of pristine asteroid rocks.