US Air Force (1947-now) Air Force Flight Test Center (AFFTC)Ser. No. 52-0003 "Balls Three" Október 1959 - Edwards AFB, CA Natural Aluminum FS16473FS28915
NASA-National Aeronautics and Space Administration (1958-now) 56-6671(Robert Rushworth) Július 1966 1st Flight with filled external fuel tanks - Edwards AFB, CA