ORBITAL AND AEROJET SET TO BEGIN AJ26 ROCKET ENGINE TESTING AT STENNIS SPACE CENTER -- Arrival of "Pathfinder" Engine to Kick Off Three-Month Testing Process for Taurus II First Stage Propulsion System --

(Dulles, VA 24 February 2010) -- Orbital Sciences Corporation (NYSE: ORB) and Aerojet, a GenCorp (NYSE: GY) company — two of the world’s leading space technology corporations — today announced the initiation of the AJ26 rocket engine testing process for Orbital’s Taurus® II medium-class launch vehicle with the delivery of a “pathfinder” engine to NASA’s Stennis Space Center in Mississippi.

Aerojet Propulsion Maneuvers Second ATV Vehicle to ISS

SACRAMENTO, Calif., Feb. 23, 2011 – Aerojet, a GenCorp (NYSE: GY) company, announced today that ESA Spacecraft PR6-2011 (Johannes Kepler) – the second of five European Automated Transfer Vehicles (ATV) – successfully launched aboard the European expendable launch system, Ariane 5, out of Kourou in French Guiana.

Aerojet Propulsion Key to NASAs Solar Dynamics Observatory (SDO) Spacecraft Positioning

 SACRAMENTO, Calif., Feb. 11, 2010 – Aerojet, a GenCorp (NYSE: GY) company, announced its key role in the positioning of NASA’s Solar Dynamics Observatory (SDO) satellite which was launched aboard the Atlas V on Feb. 11 from Cape Canaveral Air Force Station, Fla.

Aerojet Engines Integral to STS-130s Mission to Expand International Space Station

SACRAMENTO, Calif., Feb. 10, 2010 – Aerojet, a GenCorp (NYSE: GY) company, announced that its engines contributed to Space Shuttle Endeavour’s (STS-130) on-orbit operations and docking to the International Space Station (ISS). Endeavour lifted off on Feb. 8 from NASA’s Kennedy Space Center in Florida and docked with the ISS this morning.

Aerojet and Raytheon Complete System Integration Test for Standard Missile-3

SACRAMENTO, Calif., Feb. 9, 2011 – Aerojet, a GenCorp (NYSE: GY) company, and Raytheon Company (NYSE: RTN) announced today that the companies completed a kinetic warhead System Integration Test (SIT) for the Standard Missile-3 Block IB (SM-3 Blk IB) missile, verifying the ability of the kinetic warhead to detect, track and engage a ballistic missile target.