North American X-15/X-15A-2 (Aerofax Datagraph 2)

North American Aviation's (now Rockwell International) seemingly inimitable X-15 high-speed, high-altitude research aircraft remains perhaps the single most suc­cessful manned experimental flight test vehicle in U.S. history. During its nearly ten years of active flight test ac­tivity, it generated a legacy of research data and aeronautical firsts that remain unparalleled in the world of aerospace research. From materials to propulsion systems, it was a workhorse testbed that either laid or helped lay the foundations for everything from the Rockwell International Space Shuttle to the forthcoming National Aerospace Plane (now officially designated X-30A).
The X-15, in turn, owes its origins to the mid-1940's birth of the dedicated NACA/NASA, Air Force, and Navy research aircraft programs that led to the Bell X-1 fami­ly, the Bell X-2, the Douglas D-558-I, D-558-II, and X-3, the Lockheed X-7, and numerous other experimental air­craft types.