Aerojet and Lockheed Martin today conducted the third successful test firing of the Atlas® V upgraded Block B Solid Rocket Booster (SRB). Today’s test firing took place at Edwards Air Force Base, Calif.

This was the third test of the Block B upgraded motor conducted at the Air Force Research Laboratory (AFRL) test stand at Edwards Air Force Base. Previous tests were conducted May 24 and April 1, 2005.

The pre-planned SRB design upgrade will provide robust thermal margins and enhanced reliability for the Atlas V vehicle. The test conducted today featured a burn duration of approximately 90 seconds and the motor produced an average thrust of more than 250,000 lbs. Early test results indicate the motor, its insulation and nozzle performed well and according to design. Further test analyses are planned.

“The third successful test fire of the upgraded SRB today confirmed Aerojet’s modified booster design,” said Aerojet President Scott Neish. “We are very pleased with both the overall performance of the upgraded design and the collaboration with Lockheed Martin, NASA, U.S. Air Force and AFRL; the upgraded SRB translates to enhanced design margins and competitiveness of the Atlas V vehicle.”

Seven Aerojet Block A SRBs have flown successfully on three Atlas V missions that required the added SRB thrust. Five Aerojet Block B SRBs supported NASA’s Pluto New Horizon fly by mission launched January 19.

Aerojet, a GenCorp Inc. (NYSE: GY – News) company, 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 .