After nine months in orbit around asteroid Bennu, OSIRIS-REx will begin the process of maneuvering closer to the surface in preparation of the sample collection event. Once the sample site has been selected, OSIRIS-REx will break from its polar orbit to practice three flyovers of the site at increasing proximities, eventually matching Bennu's speed and rotation. The narrow-angle PolyCam will image the sample site at sub-centimeter resolution during these close passes.
When OSIRIS-REx is ready, it will slowly descend to Bennu's surface at a few centimeters per second. Its outstretched arm will touch down and blow high-pressure nitrogen gas into Bennu's soil. This will force loose dust, dirt, and rocks upward into the TAGSAM head, trapping the material inside. OSIRIS-REx will then weigh and stow the captured sample for return to Earth in 2023.