X-Plane 10.20+ Lockheed NF-104A. The NF-104 was a relatively low cost modification to three F-104A Starfighters to provide X-plane (X-15) and astronaut training for air force personnel. The addition of the 6000+ lb JP-4 / HTP, Rocketdyne LR-121-NA-1/ AR 2-3 rocket engine, allowed the NF-104 achieve astonishing altitudes above the point where aerodynamic control was lost. This way giving pilots high altitude, zero-G and space manoeuvring experience (peroxide thrusters were added to allow control above the atmosphere). Documentation includes a short history of the aircraft, flying tips and credits. By Graham Algeo.