Boeing B-52 Stratofortress NB-52A

The last B-52A built (serial 52-003) was modified and redesignated NB-52A in 1959 to carry the North American X-15. A pylon was fitted under the right wing between the fuselage and the inboard engines, with a section removed from that wing's flap to clear the X-15's tail; the X-15's liquid oxygen and hydrogen peroxide tanks were carried in the bomb bays. Its first flight carrying the X-15 was on 19 March 1959, with the first launch on 8 June 1959. Nicknamed "The High and Mighty One", the NB-52A carried the X-15 on 93 of the program's 199 flights.