A US academic/industry team is claiming the world's first flight of a liquid-propellant aerospike engine, although the rocket veered off course and crashed soon after launch.

The Prospector 2 research rocket was built by California State University, Long Beach, and Garvey Spacecraft, and powered by a student-designed 1,000lb-thrust (4.5kN) liquid-oxygen/ethanol aerospike engine.

An aerospike engine does not have a traditional bell-shaped nozzle. Instead a central spike provides the reaction surface, while the atmosphere acts as the outer wall of the bell. While a bell nozzle's geometry is optimised for one altitude, an aerospike allows the exhaust plume to expand as atmospheric pressure drops and produces thrust more efficiently over the vehicle's flight.

Preliminary analysis indicates the Prospector 2 veered off course because part of the engine's carbonfibre outer exit ring experienced excessive and asymmetric erosion, creating a side thrust component. The flight is regarded as successful because its goal was to "get the vehicle into the air using the liquid-propellant aerospike engine", says Dr Eric Besnard, an associate professor at California State University, Long Beach.

Source: Flight International