Pratt & Whitney Rocketdyne of United Technologies [UTX] recently announced that it has successfully completed a series of hot-fire tests on the certified RS-68A engine, the world’s most powerful hydrogen-fueled engine. The tests demonstrated the capability of the engine to operate for 4,800 seconds of cumulative run time – four times the design life of the engine and more than 10 times what’s needed to boost a United Launch Alliance heavy-lift rocket into space the company said. The tests took place at John C. Stennis Space Center in Mississippi.

“We are proud to celebrate this success with our United Launch Alliance customer on a test series that went above and beyond in demonstrating the robustness and reliability of the RS-68A engine,” said Dan Adamski, RS-68 program manager, Pratt & Whitney Rocketdyne. “The RS-68A performed beautifully and as expected, and test results indicate no issues with the engine hardware, further demonstrating its readiness as a heavy-lift engine. The tests also provided invaluable data that improves our ability to predict the performance of the engine on launch day.”

According to a press release, the RS-68A is a liquid-hydrogen/liquid-oxygen booster engine designed to provide increased thrust and improved fuel efficiency for the Delta IV family of launch vehicles. It evolved from the RS-68 engine, which was developed and certified for commercial use entirely on private company funds. Each RS-68A will provide 702,000 pounds of lift-off thrust, or 39,000 more pounds of thrust than the RS-68 engine, with increased combustion efficiency as well.

The company added that together with NASA, it has begun testing on the upper-stage J-2X engine. To date, five hot-fire tests have been conducted on the J-2X, which could be used to boost humans beyond low-Earth orbit.