Aerojet Powers Japans Second Successful Standard Missile-3 Intercept

SACRAMENTO, Calif., Oct. 28, 2009 – Aerojet, a GenCorp (NYSE: GY) company, announced that today the Japan Maritime Self-Defense Force achieved its second ballistic missile intercept using a Raytheon Company Standard Missile-3 (SM-3) Block IA missile. Aerojet’s MK 72 booster and MK 104 dual-thrust rocket motor provided the first- and second-stage propulsion for this critical and successful hit-to-kill intercept of a medium-range ballistic missile target in space. SM-3 is being developed as part of the U.S. Missile Defense Agency’s (MDA) sea-based Aegis Ballistic Missile Defense System. The missiles are deployed on U.S. Aegis cruisers and destroyers and Japanese destroyers to defend against short- to intermediate-range ballistic missile threats in the ascent and mid-course phases of flight.

Under contract to MDA and the Japanese Ministry of Defense, Raytheon and Mitsubishi Heavy Industries are developing the next-generation SM-3 Block IIA missile. The new missile will encompass larger second- and third-stage rocket motors and a larger kinetic warhead to provide a greater area of defense against more sophisticated threats. Aerojet is developing the Throttleable Divert and Attitude Control Systems (TDACS) for SM-3 Blocks IB and IIA, the planned missile variant upgrades to the current SM-3 Block IA.

This successful test advances Japan’s sea-based missile defense capabilities and highlights Aerojet’s leading role in providing reliable propulsion solutions for MDA, the U.S. Navy and Japan Maritime Self-Defense Force missions. “Our propulsion systems have performed reliably on every SM-3 flight and intercept test to date,” said Aerojet’s Vice President of Defense Systems, Dick Bregard.

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.