Aerojet, a GenCorp Inc. company, successfully flight tested the MARC R282 ramjet engine for the Navy GQM-163A “Coyote” target missile program.

Aerojet is responsible for development and production of the ramjet engine that powers the missile during the extended high-speed cruise phase. The missile is being developed for the Supersonic Sea-Skimming Target (SSST) Engineering and Manufacturing Development program for the United States Naval Air Systems Command. Orbital Sciences Corporation is the prime contractor.

The successful flight test represents the world’s first flight of a Variable Flow Ducted Rocket (VFDR) ramjet. The VFDR ramjet uses a solid storable fuel and a fuel control valve to deliver fuel to the ramjet combustor in response to missile commands during flight.

By using a fuel valve, thrust can be controlled depending on the desired flight profile. The storable fuel, high-speed operation for extended ranges, controllable thrust, and relatively low cost of the VFDR makes it attractive for missile applications.

The near sea level SSST flight test demonstrated a sustained speed of two and a half times the speed of sound, traveling more than 50 nautical miles. Performance predictions based on ground testing were confirmed by data collected during flight.

“The SSST flight test represents an outstanding achievement for Aerojet — validating more than 30 years of work,” said Frank Rohrback, Aerojet executive vice president. “Aerojet is committed to its goal of bringing ramjet technology to a point that it can be integrated in operational missile systems.”

Pat Hewitt, Aerojet director of Airbreathing Programs, said, “The SSST flight test truly represents a milestone in missile propulsion. Not only can we now support the SSST program requirements with the VFDR engine, but we have also developed a new high-speed missile propulsion option. This may become significant as future applications strive for sustained high speed flight and extended ranges.”

Aerojet is the sole U.S. company currently developing and producing ramjet propulsion. Other ongoing ramjet development programs include the MARC-R290 VFDR ramjet for the Navy’s High Speed Anti-radiation Missile Demonstration program, and the VFDR Flight Vehicle Concepts program for the U.S. Air Force.