The Martin X-23 PRIME (Precision Recovery Including Maneuvering Entry) was a small uncrewed lifting body re-entry vehicle tested by the United States Air Force in the late 1960s. PRIME 2 was launched on 5 March 1967. This flight simulated a 1053 km cross range re-entry, and banking at hypersonic speeds. Several stringers on the main parachute failed to cut which lead to the loss of the vehicle.