Nasa’s X-59 experimental aircraft is testing whether supersonic flight can return over land by reducing the disruptive sonic boom to a quieter sound. Its findings could help make faster-than-sound passenger travel commercially viable, while also demonstrating whether specialised crewed research aircraft remain useful in an era of rapidly advancing drones.

The X-59 first flew in 2025 and is now breaking the sound barrier over selected US communities, with residents assessing whether its boom sounds roughly like a car door closing across the street. Built from parts of T-38, F-16 and F-18 aircraft, it uses an elongated nose and a cockpit camera system; Nasa says future X-planes are likely to be uncrewed where that is practical and cheaper, though some research still requires pilots or benefits from having them.