Screen Shot 2016-06-09 at 18.15.56 Published on June 9, 2016 in 10 June 1969Full resolution (1150 × 772) ← Previous Next → North American Aviation Inc. X-15A 56-6670 hypersonic research rocketplane on display at the National Air and Space Museum. (Photo by Eric Long, National Air and Space Museum, Smithsonian Institution)