This is an artist's conception of the proposed NASA/Lockheed Martin Single-Stage-To-Orbit (SSTO) Reusable Launch Vehicle (RLV) docking with the International Space Station. NASA's Dryden Flight Research Center, Edwards, California, expected to play a key role in the development and flight testing of the X-33, which was a technology demonstrator vehicle for the proposed RLV. The RLV technology program was a cooperative agreement between NASA and industry. The goal of the RLV technology program was to enable significant reductions in the cost of access to space, and to promote the creation and delivery of new space services and other activities that would have improved U.S. economic competitiveness. The X-33 was a wedged-shaped subscale technology demonstrator prototype of a potential future Reusable Launch Vehicle (RLV) that Lockheed Martin had dubbed VentureStar. The company had hoped to develop VentureStar early this century. Through demonstration flight and ground research, NASA's X-33 program was to have provided the information needed for industry representatives such as Lockheed Martin to decide whether to proceed with the development of a full-scale, commercial RLV program. A full-scale, single-stage-to-orbit RLV was to have dramatically increased reliability and lowered the cost of putting a pound of payload into space, from the current figure of $10,000 to $1,000. Reducing the cost associated with transporting payloads in Low Earth Orbit (LEO) by using a commercial RLV was to have created new opportunities for space access and significantly improved U.S. economic competitiveness in the world-wide launch marketplace. NASA expected to be a customer, not the operator, of the commercial RLV. The X-33 design was based on a lifting body shape with two revolutionary "linear aerospike" rocket engines and a rugged metallic thermal protection system. The vehicle also was to have lightweight components and fuel tanks built to conform to the vehicle's outer shape. Time between X-33 flights was normally to be seven days, but the program had hoped to demonstrate a two-day turnaround between flights during the flight-test phase of the program. The X-33 was to be an unpiloted vehicle that took off vertically like a rocket and landed horizontally like an airplane. It was to have reached altitudes of up to 50 miles and high hypersonic speeds. The X-33 program is managed by the Marshall Space Flight Center and was to have been launched at a special launch site on Edwards Air Force Base. Due to problems with the liquide hydrogen fuel tank, and the resulting cost increase and time delay, the X-33 program was cancelled in February 2001.
