Sierra Nevada Studying X-34 As Rocket Testbed

Los Angeles — Sierra Nevada is emerging as the likely front runner to use the former NASA X-34 reusable launch vehicle demonstrator as a flying testbed for its Dream Chaser orbital space vehicle. The two surviving Orbital Sciences-built X-34s were moved by road to Mojave, Calif., on Nov. 16 from Edwards AFB, Calif., where they had been in storage since the program was canceled in 2001. The two 58.3-ft. vehicles, now stored inside a hangar belonging to the National Test Pilots School, were developed under a NASA program begun in 1996 to provide a low-cost advanced technology flight demonstration testbed vehicle for space access. Sierra Nevada Executive Vice President Mark Sirangelo confirms the company is studying the X-34 for a supporting role in the Dream Chaser development effort. “We are interested in this project with our interest being adapting our hybrid rocket motor for our orbital space vehicle Dream Chaser program to the X-34 as a test platform.” Although Sirangelo says it remains too early to provide further details, he says the X-34 could likely be adapted for carriage beneath the Scaled Composites-built WhiteKnightTwo mothership, as well as the Orbital L-1011 which last carried the vehicle aloft for three flights in 1999. Developed with the aim of reducing the cost of launching a pound of payload to orbit from $10,000 to $1,000, the X-34s were designed to test a wide range of advanced technologies. These included lightweight composite airframe structures, reusable composite propellant tanks, tank insulation, advanced thermal protection systems, integrated low-cost avionics and integrated automated vehicle health monitoring and checkout. Aimed at testing up to speeds of Mach 8 and altitudes up to 50 mi., the first X-34 vehicle, A-1, made three captive-carry flights but never achieved full, free flight before the program ended. Although originally conceived as a testbed for the reusable Fastrac engine designed and developed by NASA Marshall Space Flight Center, Ala., the vehicle is appropriately sized for the hybrid nitrous oxide, hydroxy-terminated polybutadiene-fueled rocket engine planned for the Dream Chaser. Developed by Sierra’s SpaceDev subsidiary, smaller versions of the hybrid rocket powered the Scaled SpaceShipOne, and will power Virgin Galactic’s SpaceShipTwo. The Dream Chaser is derived from the HL-20 lifting body. After several years of private funding by Sierra Nevada, the effort recently received a boost with the award of $20 million under NASA’s Commercial Crew Development (CCDEV) program, which is aimed at development of technologies that could lead to a space shuttle replacement. With an orbital goal of around 200 mi. following vertical launch using existing boosters, the Dream Chaser is designed to return for a horizontal landing. Sierra Nevada says each of the seven-seat vehicle’s multiple hybrid motors will produce about 100,000 lb. thrust, or about six times the thrust of the SpaceShipOne rocket motor. First flight of Dream Chaser is targeted for 2014.