Linear Aerospike engine to be used for propulsion for the X-33 Reusable Launch vehicle (RLV). A testing of three thrust cells of Linear Aerospike engines was conducted to investigate injectors, chambers, and Aerospike ramps at Marshall Space Flight Center (MSFC). The X-33 was intended to demonstrate advanced technologies that would dramatically increase launch vehicle reliability and lower the cost of putting a pound of payload into space.