NASA X–59 makes first (subsonic) flight

The flight marked a major (if somewhat overdue) milestone in the test and demonstration program promised when NASA's Quiet Supersonic Transport project was announced in 2016.  The one-off design is built for a purpose and packed with sensors that feed a flight test instrumentation system able to transmit 60 data streams including 20,000 parameters to engineers on the ground, and uses a modern version of the fly-by-wire system pioneered in the 1970s at the NASA Armstrong Research Center in Edwards, California, where Larson landed about an hour after takeoff.

The first flight of this one-of-a-kind prototype was subsonic, as planned, and the aircraft will gradually ramp up to its capabilities, flying Mach 1.4 at 55,000 feet. The test plan includes measuring the sound that reaches ground level in various locations, and how that sound is perceived by people. The X–59 is designed to fly at supersonic speed with its sonic boom—the audio-aerodynamic phenomenon that doomed the commercial viability of Concorde—reduced to a "gentle thump," as Lockheed described it in a press release.

Reuters reported the jet, 100 feet long with a long nose that extends far ahead of the pilot and a delta wing, cost $518 million, based on a tally of NASA contract payments since 2018, more than double the $247.5 million budget cited when construction began in 2018, and a few years beyond the then-projected 2021 first flight.

NASA is not alone seeking to bring supersonic speed back to civilian travel, and the X–59 will be sharing the Southern California sky with another supersonic prototype developed by the private sector: Boom Supersonic made the first flight of its scale XB–1 demonstrator in March 2024, pushing past the sound barrier for the first time in January during a test program that will help the company refine the design of a supersonic airliner called Overture that Boom aims to fly in 2026. Various airlines have placed orders.

The NASA effort will not produce an Overture of its own, but the X–59 could be every bit as important by creating a market for a Mach 1.7 airliner. The data and knowledge gained from flying the X–59 will inform lawmakers and regulators who must lift the longstanding ban on overland supersonic flight to allow supersonic airliners (and, potentially, business aircraft) to serve overland routes that are crucial to commercial viability.

Learn more about the project on NASA's website.