NASA’s newest high-performance rocket engine, the J-2X, successfully completed its critical design review, NASA announced.

The engine passed the milestone at Marshall Space Flight Center in Huntsville, Ala.

That J-2X engine was developed for NASA by Pratt and Whitney Rocketdyne, a unit of United Technologies Corp. [UTX].

The engine is the first element of the Constellation Program — now developing the next-generation Orion space capsule and Ares rocket — to pass this design milestone.

In the next decade, when manned flight begins, the engine will power the upper stage of the Ares I rocket and the Earth departure stage of the Ares V heavy cargo launch vehicle. Constellation also will develop the Altair lunar lander.

"The approval today by the upper stage engine critical design review board signals the beginning of manufacturing and full-scale testing of this high-performance engine," said Steve Cook, manager for the Ares projects at Marshall.

The board is comprised of engineers and project managers, including representatives from the safety and mission assurance organization, who reviewed detailed designs of the new engine. The critical design review demonstrated the maturity of the engine’s design and concluded that the planned technical approach meets NASA requirements for propulsion of the Ares I upper stage.

Full-scale testing will begin in the fall of 2010.

"The design of this propulsion system confirms that Ares I is proceeding on a solid foundation — built on years of experience by an eager team of engineers," said Teresa Vanhooser, chairperson for the J-2X Critical Design Review Board.

The J-2X engine is expected to be the most efficient engine of its type ever built. The high efficiency is achieved by using advanced design turbopumps, fuel injectors and a large extension added to the nozzle — the large, bell-shaped structure through which exhaust gases are expelled with great force as they are burned by the engine.

These enhancements deliver greater thrust, or liftoff power, while burning fuel more efficiently.

The J-2X development follows the Constellation Program goals to seek commonality between the Ares I and Ares V systems, and use proven hardware and knowledge from 50 years of American spaceflight experience to streamline development and reduce program, technical and budget risks.

Marshall manages the Ares projects and is responsible for design and development of the Ares I and Ares V vehicles. Johnson Space Center in Houston manages the Constellation Program, which includes the Ares I, the Ares V, the Orion and the Altair.

Kennedy Space Center in Florida is responsible for program ground and launch operations. The program also includes multiple project-element teams at NASA centers and contract organizations around the United States.

NASA, in the Constellation Program, is leading development of the Orion space capsule (crew exploration vehicle) by Lockheed Martin Corp. [LMT]. Orion and the Altair lunar lander will be boosted by the Ares rocket that will have various components developed by The Boeing Co. [BA], Alliant Techsystems Inc. [ATK], and Pratt & Whitney Rocketdyne, a unit of United Technologies Corp. [UTX].