Editing RL10 (section)

===Improvements===
The RL10 has evolved over the years. The RL10B-2 that was used on the [[Delta Cryogenic Second Stage|DCSS]] had improved performance, an [[nozzle extension|extendable]] [[carbon-carbon]] nozzle, electro-mechanical [[gimbaled thrust|gimbal]]ing for reduced weight and increased reliability, and a [[specific impulse]] of {{convert|465.5|isp}}.<ref>{{Cite web |title=RL-10B-2 |url=http://www.astronautix.com/r/rl-10b-2.html |access-date=16 September 2022 |website=astronautix.com}}</ref><ref name=pwr_rl10b-2.pdf/>

As of 2016, [[Aerojet Rocketdyne]] was working toward incorporating [[additive manufacturing]] into the RL10 construction process. The company conducted full-scale, hot-fire tests on an engine that had a printed main injector in March 2016.<ref>{{Cite press release |title=Aerojet Rocketdyne Successfully Tests Complex 3-D Printed Injector in World's Most Reliable Upper Stage Rocket Engine |date=March 7, 2016 |publisher=Aerojet Rocketdyne |url=http://www.rocket.com/article/aerojet-rocketdyne-successfully-tests-complex-3-d-printed-injector-worlds-most-reliable |access-date=April 20, 2017}}</ref> Another project by Aerojet Rocketdyne was an engine with a printed [[thrust chamber]] assembly in April 2017.<ref>{{Cite press release |title=Aerojet Rocketdyne Achieves 3-D Printing Milestone with Successful Testing of Full-Scale RL10 Copper Thrust Chamber Assembly |date=April 3, 2017 |publisher=Aerojet Rocketdyne |url=http://www.rocket.com/article/aerojet-rocketdyne-achieves-3-d-printing-milestone-successful-testing-full-scale-rl10-copper |access-date=April 11, 2017}}</ref>