NEWS
News, features & press releases
MISSIONS
Current, future, past missions & launch dates
MULTIMEDIA
News, features & press releases
CONNECT
News, features & press releases
ABOUT NASA
News, features & press releases

Liquid Rocket Engine Systems

The U.S. launch vehicles that will carry explorers back to the moon will be powered in part by a J–2X engine that draws its heritage from the Apollo-Saturn Program.

The new engine, being designed and developed in support of NASA’s Constellation Program, will power the upper stages of both the Ares I crew launch vehicle and Ares V cargo launch vehicle.

The Constellation Program is responsible for developing a new family of U.S. crew and launch vehicles and related systems and technologies for exploration of the moon, Mars and destinations beyond.

The J–2X will measure about 185 inches long and 120 inches in diameter at the end of its nozzle. It will weigh approximately 5,300 pounds. With 294,000 pounds of thrust, the engine will enable the Ares I upper stage to place the Orion crew exploration vehicle in low-Earth orbit.

The J–2X is being designed by Pratt & Whitney Rocketdyne of Canoga Park, Calif., for the Ares Projects Office at NASA’s Marshall Space Flight Center in Huntsville, Ala. The J–2X builds on the legacy of the Apollo-Saturn Program and relies on nearly a half-century of NASA spaceflight experience, heritage hardware and technological advances.

Powered by liquid oxygen and liquid hydrogen, the J–2X is an evolved variation of two historic predecessors: the powerful J–2 upper stage engine that propelled the Apollo-era Saturn IB and Saturn V rockets to the moon in the 1960s and 1970s, and the J–2S, a simplified version of the J–2 developed and tested in the early 1970s but never flown.