NASA's X-59 quietly advances supersonic testing as US tour looms
NASA’s X-59 quiet supersonic aircraft completed its first supersonic flight (Mach 1.1 at 43,400 ft on June 5, 2026) and a second (Mach 1.4 at 55,000 ft on June 12) as part of the Quiet Supersonic Technology program. Built as a “frankenjet” with off-the-shelf components, the long-nosed jet aims to replace loud sonic booms with a quieter thump (~75 dB) and will eventually tour the U.S. to collect public feedback and help regulators set overland supersonic standards. The aircraft uses an external vision system instead of a front cockpit window, with future tests planned to measure ground shockwaves and assess the economic viability of potential commercial overland flights.