Hydrazine Test

NASA’s X-59 quiet supersonic research aircraft is seen at dawn with firetrucks and safety personnel nearby during a hydrazine safety check at U.S. Air Force Plant 42 in Palmdale, California, on Aug. 18, 2025. The operation highlights the extensive precautions built into the aircraft’s safety procedures for a system that serves as a critical safeguard, ensuring the engine can be restarted in flight as the X-59 prepares for its first flight.