North American X-15

North American X-15 was an American aircraft that was one of the first to break the speed of sound. It was made in 1959 by North American Aviation and was used by the US Air Force until 1968. It could fly at a speed of around 4,500 miles per hour and it even went above the boundary of space! It was a very special aircraft because it helped us understand what kind of forces are at work when an aircraft breaks the speed of sound.