NASA's X-59 experimental supersonic jet sets Mach 1.53 speed record

The X-59 Quesst, an experimental supersonic aircraft developed by Lockheed Martin for NASA, reached Mach 1.53 during a set of test flights, a new top speed for the vehicle. Over six flights between September 22 and 25, it flew at roughly 1,625 kilometres per hour. The sorties were flown from the Armstrong Flight Research Center in California.

Six flights in four days also set a record for the pace of the test programme, according to the space agency. The X-59 has now completed 38 flights since its first flight in October 2025.

The aircraft is part of NASA's Quesst research programme, which examines the prospects for quieter supersonic flight. Its unusually long nose and specially shaped airframe are intended to substantially reduce the loud sonic boom normally heard on the ground.

For the planned acoustic studies, NASA has set out flights at Mach 1.4 at an altitude of about 16,800 metres. The speed just reached sits above that test range. Whether the X-59 actually produces the intended quieter boom will require further measurements.