Nasa has unveiled a one-of-a-kind quiet supersonic aircraft as part of the US space agency’s mission to make commercial supersonic flight possible. In a joint ceremony with Lockheed Martin Skunk Works in Palmdale, California, on Friday, Nasa revealed the X-59, an experimental aircraft that is expected to fly at 1.4 times the speed of sound – or 925mph (1,488 km/h).more