Will Build New Test Stand At Stennis For J-2X Evaluation

NASA engineers have successfully completed testing of subscale main injector hardware, an early step in development of the RS-68 engine that will power the core stage of NASA's upcoming Ares V -- the cargo launch vehicle that will deliver large-scale hardware and systems to space for exploration missions to the moon.

Engineers at NASA's Marshall Space Flight Center in Huntsville, AL recently conducted multiple hot-fire tests on the injector hardware. The injector is a major component of the engine that injects and mixes liquid hydrogen and liquid oxygen propellants in the combustion chamber, where they are ignited and burned to produce thrust.

The tests support the design and development of Ares V under the Constellation Program, which is responsible for overall development of the spacecraft and launch vehicles systems for NASA's exploration initiative to return to the moon and travel to Mars and destinations throughout our solar system.

The tests, begun in February, were part of a series investigating different injector element designs for propellant flow. During testing, engineers fired the injectors for durations of 10 to 20 seconds.

The hot-fire tests of the hardware and number of injector elements are part of efforts to investigate design options and maximize performance of the RS-68 engine. A cluster of five RS-68 engines will power the core stage of the Ares V. The engine will be an upgraded version of those now used in the Delta IV, the largest of the Delta rocket family developed in the 1990s by the US Air Force for its Evolved Expendable Launch Vehicle Program.

Data from the tests also will be used to develop the J-2X engine systems for the upper stages of Ares V and for Ares I, the crew launch vehicle that will carry the Orion spacecraft and its crew of astronauts to Earth orbit.

The injector hardware for the RS-68 and J-2X engines share design features similar to the subscale hardware, such as the type of elements and density patterns. This hardware commonality makes operations more cost effective for both the crew and cargo vehicles.

And speaking of the J-2X, NASA also announced this week the space agency will erect a new engine test stand at the Stennis Space Center in Mississippi, to conduct tests on the test the revamped engine.

Stennis already is home to Apollo-era test stands that have served the nation's space program through the shuttle era. The newly proposed structure will be the first large test stand built at the center since the 1960s, near the site where the original Apollo-era J-2 rocket engines that first carried astronauts to the moon were tested.

Unlike the older structures, the new 300-foot-tall, open-frame design will allow engineers to simulate conditions at different altitudes.

NASA engineers need to simulate various altitudes to test the J-2X's ability to function as a second stage engine for the Ares I crew launch vehicle and the Earth Departure Stage engine for the Ares V cargo launch vehicle. To do that, the test stand will generate approximately 4,620 pounds per second of steam and use it to reduce the engine test cell pressure.

NASA aims complete the new stand in time to support the first J-2X engine test in December 2010. An existing test stand at Stennis also is being modified to test the J-2X engine at sea level conditions.

"This new test stand will enable the critical testing needed to verify the Ares I upper stage engine performance at altitude conditions," said Stennis Center Director Rick Gilbrech. "The Apollo-era test stands have served us well over the last forty years, and I'm excited that NASA will have a new stand to help us accomplish these new goals."

The test stand, along with its control center, propellant barge docks and access roadways, will be built in Stennis A Complex.

FMI: www.nasa.gov/constellation