Problems in ultra-high-speed flight

Since the days of the Wright Brothers the term high-speed flight has been used to denote flight at speeds just within the bounds of practical accomplishment. “High speed” has meant each year since 1903 about 15 miles per hour faster than the year before until October 14, 1947. On that date Charles E. Yeager, then a captain in the U. S. Air Force, flew the Bell X-1 research airplane faster than sound. Since then the word supersonic has become a familiar adjective, descriptive of the speed of certain aircraft and missiles.