NASA has bolstered its flight research capabilities with the addition of two retired F-15 fighter jets from the U.S. Air Force to support testing of its new X-59 “quiet” supersonic aircraft. The X-59 is designed to fly at supersonic speeds while dramatically reducing sonic booms, a development that could revolutionize commercial air travel and shorten long-haul flight times.

Delivered in December 2025 to NASA’s Armstrong Flight Research Center in California’s Mojave Desert, the F-15s will assist research flights as chase planes and carry specialized sensors to measure air pressure and shock waves generated by the X-59. One F-15 will be outfitted with new equipment and software for dedicated research purposes, while the other will serve as a source of parts to maintain the fleet.

“These two aircraft will enable successful data collection and chase plane capabilities for the X-59 through the life of the Low Boom Flight Demonstrator project,” said Troy Asher, director of flight operations at NASA Armstrong. The X-59 itself cruises at 55,000 feet (17 km), with chase planes capable of following at 60,000 feet (18 km) to capture critical flight data.

NASA has a long-standing history of using F-15 jets for aeronautical research dating back to the 1970s, including carrying Schlieren photography systems and sensors to visualize airflow and pressure changes. These jets have contributed to decades of advancements in high-speed flight, and their addition to the X-59 program marks a continuation of that legacy.

The X-59 flew for the first time in October 2025, with Lockheed Martin, the aircraft’s manufacturer, confirming that the plane “performed exactly as planned.” The test flights aim to provide data on how the aircraft can operate commercially without producing disruptive sonic booms over populated areas.

For more context, USA Herald previously covered the X-59’s supersonic tests, highlighting its potential impact on commercial aviation and global travel times.

NASA’s work with the X-59, supported by these new F-15s, represents a crucial step toward developing quiet supersonic flight technology that could eventually reshape how passengers experience air travel worldwide.