Aerojet, a GenCorp Inc. (NYSE: GY) company, has completed the design, development and testing of a new non-toxic reaction control engine that has potential application in meeting NASA’s need for on-orbit propulsion in support of the Vision for Space Exploration, NASA’s plan to return man to the Moon and for further exploration of Mars. The oxygen-based engine offers advantages over traditional hydrazine- based systems, such as reduced environmental impacts and improved operability.

Three engines, each capable of delivering 870 pounds of thrust, were delivered to NASA’s White Sands Test Facility, New Mexico, two months ahead of schedule, meeting NASA’s goal for a shortened manufacturing timeline to support the non-toxic system level testing, which will begin in August 2005. Aerojet demonstrated flexibility and agility of the development process by completing design, manufacturing, acceptance testing and delivery in just seven months.

The accelerated schedule included detailed manufacturing and quality planning processes, and an updated injector design to improve engine specific impulse performance, known as Isp. In a rocket engine, Isp measures the combustion efficiency — somewhat like “miles per gallon” in an automobile engine. The measured Isp of 292 seconds with a 22:1 nozzle area ratio was outstanding for the propellant combination and the chamber pressure used.

Aerojet is a world-recognized aerospace and defense leader principally serving the missile and space propulsion, and defense and armaments markets. GenCorp is a leading technology-based manufacturer of aerospace and defense products and systems with a real estate business segment that includes activities related to the development, sale and leasing of the Company’s 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 .