The company said Tuesday it tested RL10C-X in a flight-like configuration to showcase its long-duration endurance and full mission capability.
The test took place in a test chamber designed to replicate an outer space condition, with RL10C-X also demonstrating its ignition capability even at extreme in-flight settings.
The upper-stage engine, which is the latest in the RL10 series, features 3D printed major components including a combustion chamber and an injector.
Eileen Drake, president and CEO of Aerojet Rocketdyne, said the testing's completion demonstrates that 3D-printing can be used in the RL10 program to save resources while not sacrificing engine performance.
RL10C-X has undergone over 5,000 seconds of full-engine, hot fire testing in total.
United Launch Alliance plans to eventually use RL10C-X for the Vulcan Centaur rocket's upper stage. Aerojet Rocketdyne works on RL10C-X in partnership with the U.S. Air Force.