NASA has taken a significant step forward in its pursuit of quieter supersonic flight by adding two F-15 aircraft to its flight research fleet, according to information released by the agency and detailed by Space.com, with additional context from official NASA imagery and documentation. The move supports the ongoing development of the X-59 quiet supersonic aircraft, a program designed to reshape how high-speed flight is perceived and regulated. F-15 Aircraft Take On a New Role at NASA ArmstrongThe newly acquired F-15 fighter jets are now based at NASA Armstrong Flight Research Center in California, where they will serve as critical support aircraft for high-speed testing. A NASA F-15 aircraft sits 20 feet off the left side of the X-59 aircraft, with a white hangar and hills in the background, during electromagnetic interference testing. Two NASA F-15 aircraft sit on the ramp at NASA’s Armstrong Flight Research Center, in Edwards, California.