ST. LOUIS, "The X-31 thrust-vectoring aircraft, first used in the 1990s to successfully demonstrate enhanced combat maneuverability, has taken flight again in a new program called VECTOR, focused on demonstrating extremely short- takeoff-and-landing (ESTOL) capabilities. VECTOR (for Vectoring ESTOL Control Tailless Operation Research) is a joint venture of the U.S. Navy, Boeing, Germany's federal...