NASA's 2017 astronaut candidates toured aircraft hangar at Armstrong Flight Research Center, in Southern California where (L to R) Loral O'Hara, Jenni Sidey-Gibbons and Raja Chari look inside the engine nozzle of an F-15 jet. The F-15 will fly in tandem with the X-59 QueSST during early flight test stages for the X-59 development.