After months of test flights, NASA’s X-59 aircraft is gearing up for its biggest challenge yet: breaking the sound barrier without producing a loud, thunder-like clap. The experimental aircraft is set to embark on a new round of test flights this month, which will include its first time flying faster than the speed of sound, NASA recently announced. The team behind X-59 reviewed the aircraft’s progress throughout the past several months and gave it the green light for the next series of test flights. “What comes next is the first time this one-of-a-kind aircraft will fly supersonic,” Cathy Bahm, project manager for NASA’s Low Boom Flight Demonstrator, said in a statement. “We are starting toward the mission conditions test point that X-59 was designed for.” Onward and upward The experimental aircraft, built by aerospace contractor Lockheed Martin, took to the skies for its inaugural flight on October 28, 2025. For its first flight, the aircraft operated slower than the speed of sound at 230 miles per hour (370 kilometers per hour) and a maximum altitude of about 12,000 feet (3.6 kilometers). X-59 spent around one hour in the air before landing near NASA’s Armstrong Flight Research Center in Edwards, California.