OSIRIS-REX GROUND FORCE MODELING COMPARED TO IN-FLIGHT EXECUTION

The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) spacecraft performed its "Touch and Go" (TAG) sampling maneuver on October 20, 2020, during which it briefly was in contact with the surface of the asteroid Bennu. Pre-flight verification models of the sampling event were bounded by defining “soft” and “hard” ground conditions. A broad range was necessary because the properties of the surface and how much force it would impart on the sampling system were unknown prior to contact. The in-flight interaction between the spacecraft's sampling mechanism and the asteroid surface provided information that was used to fit the pre-flight models to the observed telemetry. The inertial measurement unit (IMU) data from TAG showed the surface response generated a force profile even lower than the soft-ground model.