Aerojet, a GenCorp (NYSE:GY) company, announced today that the company completed a hot firing test sequence of a new roll control thruster being developed as a candidate for NASA’s Ares I launch vehicle. This was a significant milestone as it is the first firing of the improved engine design including a new valve that meets redundancy criteria ensuring crew safety and provides pulsing capability that is critical for the roll control application. The test firing met all of NASA’s performance requirements.

The Ares Roll Control System Advanced Development Program was awarded in the spring of 2007 for development based on Aerojet’s heritage MR-80 600 lbf-class monopropellant rocket engine. The MR80 had previously flown on the NASA Viking missions to Mars, where it provided throttling of greater than 70:1 for a terminal descent and soft landing. The thruster was redesigned for pulsing application with the new valve and Aerojet also implemented a series of product improvements to reduce the recurring unit costs of the engines. The design improvements were obtained using the Design for Manufacturability and Assembly (DFMA) process which is part of Aerojet’s overall Operational Excellence initiative.

Development testing started in December 2008 with a successful random vibration test, demonstrating the engine’s ability to withstand launch vibration loads. “Aerojet is proud to provide NASA with a design solution that builds on the great heritage of the MR-80 and meets the unique requirements of the Ares launch vehicle,” said Julie Van Kleeck, Aerojet’s vice president of Space Programs.

The Ares Roll Control System Advanced Development Contract is managed by the Exploration Launch Office at NASA Marshall Space Flight Center in Huntsville, Ala.

Aerojet is a world-recognized aerospace and defense leader principally serving the missile and space propulsion, defense and armaments markets. GenCorp is a leading technology-based manufacturer of aerospace and defense products and systems with a real estate segment that includes activities related to the entitlement, sale, and leasing of the company’s excess real estate assets. Additional information about Aerojet and GenCorp can be obtained by visiting the companies’ Web sites at http://www.aerojet.com/ and http://www.gencorp.com/.