The X-34 is one of NASA's new technology demonstrator programs that will pave the way to lower launch costs.  The X-34 vehicle is being built by Orbital Sciences Corporation in Dulles, VA.  The X-34 will be carried aloft by the OSC L-1011 carrier aircraft.  The X-34 will be released at an altitude of approximately 20,000 feet before igniting it's LOX / kerosene Fastrac engine.  The vehicle will accelerate to speeds of Mach 8 and achieve an altitude of 250,000 feet before dumping propellants and gliding to a runway landing.

Technical Objectives of the X-34 Program (as described by NASA) (as described by NASA)

• Readily enable integration of new technologies
• Capable of 25 test flights over a period of one year
• Capable of autonomous flight operations
• Capable of demonstrating safe abort
• Demonstrate technologies throughout flight profile
• Subsonic and hypersonic flight
• Capable of powered flight to at least 250 kft
• Capable of eventually attaining Mach 8
• Demonstrate or be upgradable to advanced RLV technologies
• Incorporate some composite structures (aero, prime airframe and thrust structures)
• Composite propellant tanks and cryo insulation
• Composite lines, ducts, valves
• Advanced operable TPS including leading edge materials
• Advanced low cost avionics (GPS/INS)
• Rapid low cost flight software development tools
• Integrated vehicle health monitoring
• Capable of attaining average recurring flight cost
• Adaptable as a low Mach number test bed (embedded, attached, or deployed) e.g.., RBCC; Plug Nozzle; Pulse detonation wave; dual expansion engines