NASA's experimental X-59 supersonic jet, often referred to as the 'Son of Concorde,' successfully broke the sound barrier for the first time on Friday, June 5, reaching a speed of Mach 1.1, or 713 miles per hour (1,150 km/h). The aircraft took off and landed from Edwards Air Force Base in California, reaching an altitude of 43,400 feet during the 81-minute flight.
This milestone is a critical step toward potentially enabling ultra-fast air travel, similar to the Concorde's London-to-New York routes, which could be completed in under four hours. NASA aims to further test the X-59's capabilities in the coming days, with plans to reach Mach 1.4, or 925 miles per hour (1,490 km/h), as part of its Quiet SuperSonic Technology (Quesst) project.
The primary goal of the Quesst program is to address the loud sonic booms that previously grounded supersonic passenger flights. Traditional supersonic jets create intense shockwaves as they exceed the speed of sound, resulting in booms that can reach 110 decibels, leading to bans over populated areas. The X-59, developed by Lockheed Martin's 'Skunk Works' division under a $247.5 million NASA contract awarded in 2016, features a distinctive long, tapered nose designed to diffuse these shockwaves and reduce the noise to a quiet 'thump.'
Due to its unique design, the X-59's cockpit is positioned mid-fuselage and lacks forward-facing windows. Pilots rely on an external vision system, utilizing cameras and augmented reality displays, to navigate. NASA estimates this system will reduce the perceived sound on the ground to a level comparable to a distant thunderclap or a car door closing 20 feet away.
Test pilot Jim 'Clue' Less piloted the X-59 during its initial supersonic flight. The aircraft was monitored by an F-15 chase plane equipped with a probe to measure the shockwaves generated by the X-59, though the sonic boom from the F-15 initially obscured the X-59's sound signature.
Subsequent flights will involve testing the X-59 at mission conditions, including a planned flight to Mach 1.4 at 55,000 feet. These tests are crucial as they simulate the speeds and altitudes at which the jet will eventually be flown over populated communities in the U.S. The final phase of testing will focus on verifying the aircraft's quiet sonic thump capability by flying it over these communities and collecting public perception data.
NASA intends to share this data with regulatory bodies, both domestically and internationally, to help establish new noise standards. These standards could pave the way for a viable market for supersonic commercial flights over land, a possibility that was curtailed with the retirement of Concorde in 2003 due to factors including operational costs, a downturn in the aviation industry, and safety concerns following its sole fatal crash.
Concorde, which first flew in 1969 and entered commercial service in 1976, was jointly developed by Aérospatiale and the British Aircraft Corporation. It operated at speeds over twice the speed of sound, but its legacy was significantly impacted by its sonic boom and eventual discontinuation. The Bell X-1, piloted by Chuck Yeager, first broke the sound barrier in 1947.