The new engines will be part of the heavy-lift launch vehicle Vulcan Centaur rocket which ULA says is part of a contract it received from Amazon, as part of the largest commercial launch contract in history, to support the launch of its Kuiper satellite constellation.
The RL10C-X uses a 3D printed main injector and main combustion chamber, as well as a 94-inch monolithic lightweight nozzle.
"The RL10 is the highest performance upper-stage rocket engine flying today," said ULA president and CEO Tory Bruno. "We’re proud to be launching the Kuiper constellation with the next generation of this incredibly reliable and high-performance engine."