Pratt and Whitney Rocketdyne successfully completed the last hot-fire test on the J-2X powerpack - an important step toward development of America's next rocket engine designed for human spaceflight.

NASA has selected the J-2X as the upper-stage propulsion for the Space Launch System (SLS), an advanced heavy-lift launch vehicle. Pratt and Whitney Rocketdyne is a United Technologies Corp. company.

"This is a significant milestone in the development of the J-2X engine," said Walt Janowski, program manager, Pratt and Whitney Rocketdyne.

"We put the powerpack through a series of demanding tests, pushing it to its limits and acquiring valuable information to help us better understand how the engine will perform during flight. We look forward to continuing to work with NASA in its quest to provide a safe, reliable transportation system to explore deep space."

The J-2X powerpack tests were designed to evaluate the full range of operating conditions of the engine's components during flight. The powerpack was tested separately from the engine because it can be operated more thoroughly and at a wider range of conditions than a fully assembled engine.

The powerpack consists of components on top of the engine, including the gas generator, the oxygen and fuel turbopumps, and the ducts, valves and controls that bring the propellants together to drive the turbines of the two turbopumps.

Throughout the test series, which began in February 2012 at John C Stennis Space Center in Mississippi, the powerpack was fired 13 times for a total of more than 100 minutes - at one point breaking a single-test record of 1,350 seconds on the A-1 test stand.

Pratt and Whitney Rocketdyne engineers used varying pressures, temperatures and flow rates to ensure the engine is ready to support exploration to low-Earth orbit, Mars and beyond.