Group : Rocket Engines
Status : Active
Also Known As : RL10A, RL10B
Origin : United States of America
Contractor : Aerojet Rocketdyne
Initial Operational Capability (IOC) : 1963
First Flight : 1959
Total Production : ?

The RL10 upper stage rocket motor was developed by Aerojet, now Aerojet Rocketdyne, in the 1950s to support the Atlas Centaur space launch system. The engine burns a mixture of liquid hydrogen and liquid oxygen (LOx). The first RL10 upper stage conducted its first flight in 1959 and entered service in 1963. With more than 500 engines produced so far the RL10 is currently being used by the Delta IV (RL10B-2) and Atlas V (RL10A-4-2) space launch systems. The RL10 rocket engines are expected to play a major role in the space exploration programs in the late 2010s and early 2020s.

Group : Rocket Engines
Status : Under Development
Also Known As : RL10C-1
Origin : United States of America
Contractor : Aerojet Rocketdyne
Initial Operational Capability (IOC) : 2019
First Flight : 2014
Total Production : ?

The Aerojet Rocketdyne RL10C is a further variant of the RL10 designed to serve as the upper stage for the OmegA space launch system. The same upper stage may be adopted by the New Glenn and Vulcan Centaur space launch systems also being developed under the US Air Force (USAF) Evolved Expandable Launch Vehicle (EELV) program. The first launch of the RL10C-1 was carried out in 2014 and is expected to support the first launch of the Vulcan Centaur in 2020.