Aerojet, a GenCorp
Inc. company, will provide the world’s longest monolithic solid
rocket boosters for extra lifting power on Lockheed Martin’s Atlas® V launch
vehicle, which is planned to launch on Friday, Dec. 17.

Aerojet’s single-structure solid rocket boosters are 67-feet long and
provide 250,000 lbs. of thrust, which will be used to lift the AMERICOM 16
spacecraft.

In addition to providing extra power for the launch vehicle with the two
solid boosters, Aerojet will also provide 12 thrusters for the upper stage;
four electric propulsion systems and 18 monopropellant thrusters on the
spacecraft.

Friday’s launch will be the second flight of the Atlas V with Aerojet’s
solid rocket boosters. The first launch took place in July 2003.

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 .

Forward-Looking Statements

This press release contains forward-looking statements based on current
management expectations. Numerous factors, including those related to market
conditions and those detailed from time to time in GenCorp’s filings with the
Securities and Exchange Commission, may cause results to differ materially
from those anticipated in the forward-looking statements. Many of the factors
that will determine GenCorp’s future results are beyond the ability of GenCorp
to control or predict. These statements are subject to risks and uncertainties
and, therefore, actual results may differ materially. Readers should not place
undue reliance on forward-looking statements, which reflect management’s views
only as of the date hereof. GenCorp undertakes no obligation to revise or
update any forward-looking statements, or to make any other forward-looking
statements, whether as a result of new information, future events or
otherwise.