The tests allowed evaluation of how engine components would operate in various flight conditions.
"The successful powerpack test provided important data that verified the engine's components and gave us a better understanding of how the turbo-pumps operate," said Walt Janowski, J-2X program manager, Pratt and Whitney Rocketdyne.
"Each new test brings us closer and closer to engine certification and we are confident the J-2X will be ready to power humans to destinations in space never before visited, including asteroids and Mars."
Powerpack components tested included a gas generator, oxygen and fuel turbo-pumps and the ducts, valves and controls that bring the propellants together to drive the turbines of two turbo-pumps.
Pratt and Whitney Rocketdyne said hot-fire tests on the powerpack will continue until the fall. In those test, the components will be subjected to varying pressures, temperatures and flow rates.
The J-X2 engine will be the upper-stage propulsion system for NASA's Space Launch System.