Summary and Key Points: The X-15 program, spanning 199 flights between 1959 and 1968, pushed the boundaries of aeronautics into the hypersonic realm. -Capable of reaching altitudes of 102,000 feet, ...

The North American X-15 did more than set records; it quietly redrew the map of what a piloted aircraft could survive at the edge of space. By pushing hypersonic flight to extremes that still stand ...