The successful hot-fire test of an RS-25 development engine at Stennis Space Center included NASA’s largest 3D-printed rocket engine component to date. (NASA/Stennis)

Engineers successfully hot-fire-tested an RS-25 rocket engine with a large 3D-printed part for the first time, marking a key step toward reducing costs for future engines that power NASA’s new heavy-lift rocket, the Space Launch System.

The part is a beachball-sized piece of hardware that acts as a shock absorber by regulating liquid oxygen movement in the engine to prevent the vibrations that can destabilize a rocket’s flight. Initial reports show the 3D-printed hardware performed as expected, opening the door for more components scheduled for future tests.