Aerojet’s liquid second-stage engine helped power the Boeing Delta II launch vehicle and its Global Positioning System (GPS) satellite into orbit today for the U.S. Air Force from Cape Canaveral Air Force Station in Florida.

Aerojet’s Delta II second stage engines are among the world’s most reliable and this launch marks the 253rd successful Delta launch to date using Aerojet’s second-stage engines. Aerojet, a GenCorp Inc. (NYSE: GY) company, has provided second stage engines for the Delta II since 1982. Aerojet also provides 16 thrusters for the GPS satellite’s in-space maneuvering requirements.

Aerojet’s second stage liquid rocket engine owes its longevity to a robust design and the use of proven components that have evolved over the engine’s lifetime to enhance performance and meet customer requirements. Aerojet second stage engine support of Boeing’s Delta II vehicles will continue through at least 2010.

Aerojet’s satellite thrusters have successfully flown on every GPS mission to date ensuring the United States has GPS navigation capability vital to both the commercial and military communities.

This satellite is the third successful modernized navigation satellite launched to aid military and civilian users. The spacecraft provides critical upgrades to GPS navigation services by adding an additional civilian signal as well as robust military channels that are less susceptible to jamming.

Aerojet is a world-recognized aerospace and defense leader principa lly 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 .