Flight Test and Analysis of a Multi-Chamber Aerospike Engine *

Despite the promise of improved performance, aerospike engines have yet to be used on any operational system, owing in large part to the fact that no flight data is available to characterize the interactions between airframe and engine, most notably in transonic, under-expanded flight conditions. The paper discusses the development of a multi-chamber 1,300 lbf thrust LOX/ethanol aerospike engine designed to address this need. The engine is comprised of ten (10) thrusters which incorporate ceramic matrix composite thrust chambers in order to maintain the square 0.6 inch throat and rectangular nozzle constant during the burn. The thrusters are arranged around an annular plug nozzle which is outfitted with a series of pressure sensors in order to obtain flight performance data to be later used for computational fluid dynamics (CFD) tool validation. The engine is integrated into a regulated-helium pressure-fed vehicle which features flight data acquisition and telemetry systems. Sensors include an inertial measurement unit, propulsion system pressure transducers, as well as skin pressure sensors. The vehicle is designed to reach supersonic conditions at approximately 15,000 ft and burnout shortly thereafter, coasting to 25,000 ft before a 2-stage parachute recovery. The flight data will later be analyzed to determine airframe-engine interactions and the associated engine performance, and will be used for comparisons with CFD approaches.