January 15, 2006

Five Aerojet Boosters Set to Lift New Horizons Spacecraft

Aerojet Propulsion Will Support Both Launch Vehicle and Spacecraft for Mission to Pluto

SACRAMENTO, Calif., Jan. 15 /PRNewswire/ -- Aerojet, a GenCorp Inc. (NYSE: GY) company, will provide five solid rocket boosters for the launch vehicle and a propulsion system for the spacecraft when a Lockheed Martin Atlas® V launches the Pluto New Horizons spacecraft January 17 from Cape Canaveral, AFB. The launch window opens at 1:24 p.m. EST on January 17 and extends through February 14.

The New Horizons mission, dubbed by NASA as the "first mission to the last planet," will study Pluto and its moon, Charon, in detail during a five-month- long flyby encounter. Pluto is the solar system's most distant planet, averaging 3.6 billion miles from the sun.

Aerojet's solid rocket boosters (SRBs), each 67-feet long and providing an average of 250,000 pounds of thrust, will provide the necessary added thrust for the New Horizons mission. The SRBs have flown in previous vehicle configurations using two and three boosters; this is the first flight utilizing the five boosters. Additionally, 12 Aerojet monopropellant (hydrazine) thrusters on the Atlas V Centaur upper stage will provide roll, pitch, and yaw control settling burns for the launch vehicle main engines. Aerojet also supplies 8 retro rockets for Atlas Centaur separation.

Aerojet also provided the spacecraft propulsion system, comprised of a propellant tank, 16 thrusters and various other components, which will control pointing and navigation for the spacecraft on its journey and during encounters with Pluto- Charon and, as part of a possible extended mission, to more distant, smaller objects in the Kuiper Belt.

Aerojet is under contract with Lockheed Martin for the SRBs, thrusters and retro rockets, and Johns Hopkins University/Applied Physics Laboratory (JHU/APL) for the spacecraft propulsion system. JHU/APL designed and built New Horizons for NASA and will operate the spacecraft after launch.

Aerojet developed, produced and tested the SRBs in California, using technology derived from its extensive experience producing solid rocket motors for Peacekeeper and Small ICBM missile systems. The boosters will be ignited at liftoff and burn for 85 to 90 seconds providing more than 1,250,000 pounds of thrust to get the launch vehicle off the pad and through Earth's atmosphere.

The spacecraft propulsion system was designed, produced and tested in Washington, and will support the spacecraft through the duration of the mission -- approximately 16 years. The spacecraft propulsion system uses technology developed by Aerojet for NASA's Jet Propulsion Laboratory's Voyager 1 and 2 spacecrafts, launched in 1977 and now the farthest distant man-made objects in the solar system. The MESSENGER spacecraft, now on its way to Mercury, also features an Aerojet propulsion system built for JHU/APL and uses technology also traceable to Voyager.

The spacecraft's propulsion system provides steering and fine pointing for cruise and encounter mission phases. Highly specialized fabrication techniques were utilized in the propulsion system fabrication and integration process in order to minimize leak risks and meet the long-life requirements of the mission.

"The upcoming Atlas launch supporting the New Horizons mission will be another crowning moment for Aerojet," said company President Scott Neish. "The five solid rocket boosters will provide an extraordinary start to an exciting scientific mission to Pluto. The Aerojet propulsion system will then guide the spacecraft on its long trip to Pluto and enable the spacecraft to properly orient itself while science is gathered."

"Aerojet's contributions to scientific research of the solar system are ongoing. With the anticipated mapping of the planet Mercury by MESSENGER, and the arrival of New Horizons at Pluto, Aerojet will have provided propulsion for spacecraft visiting every planet in the solar system."

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. SOURCE: Aerojet 01/15/2006 CONTACT: Rob Huff of Aerojet, +1-916-355-2143, [email protected], or Linda Cutler of GenCorp, +1-916-351-8650, [email protected] Web site: http://www.gencorp.com http://www.Aerojet.com (GY)