The powerful liquid hydrogen-fed engine NASA is developing to propel hardware and humans out of Earth orbit underwent a successful ground test-firing in Mississippi on Wednesday afternoon.

Steam billows from the Stennis engine test stand. Credit: NASA TV

The J-2X powerplant built by Pratt & Whitney Rocketdyne will be fitted to the upper stage of the Space Launch System heavy-lift rocket that will send manned missions to deep space.

"The J-2X engine is critical to the development of the Space Launch System," Dan Dumbacher, NASA's deputy associate administrator for exploration systems development, said after the test at NASA's Stennis Space Center in Mississippi. "Today's test means NASA is moving closer to developing the rocket it needs if humans are to explore beyond low-Earth orbit."

On the A-2 test stand at the Stennis Space Center, the engine roared to life at 4:04 p.m. EST (2104 GMT) for a 499.97-second firing to simulate flight conditions at its full-power throttle setting.

It is the same facility originally built in the 1960s for Apollo testing and then used to fire space shuttle main engines before being retrofitted to support the J-2X.

This engine itself was derived from the J-2 cryogenic powerplant used aboard the Saturn 5 moon rockets a half-century ago.

Generating 294,000 pounds of thrust in vacuum, the engine stands 15 feet tall, weighs 5,450 pounds and consumes supercold liquid oxygen and liquid hydrogen.

Tests like the one Wednesday will continue over the next several years as engineers learn the operating characteristics of the J-2X.

"The J-2X engine team and the SLS program as a whole are extremely happy that we accomplished a good, safe and successful test today," said Mike Kynard, Space Launch System Engines Element Manager at NASA's Marshall Space Flight Center in Huntsville, Ala. "This engine test firing gives us critical data to move forward in the engine's development."

The first launch of the SLS heavy-lifter rocket with the J-2X engine is tentatively targeted for 2017.

Additional coverage for subscribers:
VIDEO: J-2X ENGINE TEST-FIRED PLAY | HI-DEF
VIDEO: WATCH ENTIRE ENGINE TEST BROADCAST PLAY
VIDEO: POST-TEST NEWS BRIEFING PLAY
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