LASRE was a small, half-span model of the X-33's lifting body with eight thrust cells of an aerospike engine, rotated 90 degrees and mounted on the back of an Lockheed SR-71 Blackbird aircraft, to operate like a kind of "flying wind tunnel." The experiment focused on determining how a reusable launch vehicle's engine plume would affect the aerodynamics of its lifting body shape at specific altitudes and speeds reaching about 750 miles/hour (335 meter/second or 1207 km/h). Design refinements looked to minimize the interaction of the aerodynamic flow with the engine plume, which could create drag.