These days, when people hear abouthypersonicexperimentation, typically, the discussion surrounds hypersonic missiles, but in the 1960s, the X-15 hypersonic rocket-powered aircraft would have come to mind. North American's X-15 pushed the boundaries of science and was a crucial step in America's space program and going to the moon. Before Neil Armstrong stepped onto the moon, he flew the experimental X-15. The X-15 was a rocket plane that skirted the edge of space and continues to holdthe world record for the fastest airplane that ever flew.
