NASA failed to attract industry co-investment to develop an X-34 air-launched, reusable, low-technology, low-cost launch vehicle. So the project was scaled back and NASA contracted with Orbital Sciences to build and fly an unmanned technology demonstrator. Objectives were to demonstrate new, efficient vehicle processing and launch operations and evaluate the performance of advanced reusable launch vehicle technologies. The program was to demonstrate a nominal two-week turnaround between flights, and a surge capability of two flights within 24 hours. The single stage vehicle used NASA’s low cost Fastrac engine for liquid oxygen/kerosene propulsion. The vehicle itself used all-composite primary and secondary structure. Its autonomous flight control system was to make automated approach and landings. Flights were planned to speeds of Mach 8 over an 800 km range. The contract with Orbital Sciences covered construction of three flight vehicles and 26 powered and unpowered flights launched from an L-1011.

Payload: 400 kg. to a: Mach 8, 76 km trajectory. trajectory. Liftoff Thrust: 27,423 kgf. Total Mass: 26,500 kg. Total Length: 17.7 m.

• Stage Number: 1. 1 x X-34 Gross Mass: 21,800 kg. Empty Mass: 8,200 kg. Thrust (vac): 27,423 kgf. Isp: 310 sec. Burn time: 150 sec. Span: 8.5 m. Length: 17.7 m. Propellants: Lox/Kerosene No Engines: 1. Fastrac