Editing RL10 (section)

==Applications==

=== Current ===
*[[Centaur (rocket stage)|Centaur III]]: The single engine centaur (SEC) version uses the RL10C-1,<ref name="Aerojet Rocketdyne 2" /> while the dual engine centaur (DEC) version retains the smaller RL10A-4-2.<ref name="EA10A1" />  An Atlas V mission (SBIRS-5) marked the first use of the RL10C-1-1 version.  The mission was successful but observed unexpected vibration, and further use of the RL10C-1-1 model is on hold until the problem is better understood.<ref>{{Cite web |date=June 23, 2021 |title=ULA delays further use of enhanced upper-stage engine pending studies |url=https://spacenews.com/ula-delays-further-use-of-enhanced-upper-stage-engine-pending-studies/}}</ref> The engine was used again successfully on SBIRS-6.
*[[Centaur V]] stage: On May 11, 2018, [[United Launch Alliance]] (ULA) announced that the RL10 upper stage engine had been selected for its [[Vulcan (rocket)|Vulcan Centaur]] rocket following a competitive procurement process.<ref>{{Cite web |date=May 11, 2018 |title=United Launch Alliance Selects Aerojet Rocketdyne's RL10 Engine |url=https://www.ulalaunch.com/about/news/2018/05/11/united-launch-alliance-selects-aerojet-rocketdyne-s-rl10-engine-for-next-generation-vulcan-centaur-upper-stage |access-date=May 13, 2018 |publisher=ULA}}</ref> Early versions of the Centaur V will use the RL10C-1-1,<ref name="Aerojet Rocketdyne 2" /> but later versions will transition to the RL10C-X.<ref>{{Cite web |title=Vulcan Cutaway Poster |url=https://www.ulalaunch.com/docs/default-source/rockets/vulcancentaur.pdf?sfvrsn=10d7f58f_2 |access-date=October 15, 2021 |website=United Launch Alliance}}</ref> Vulcan flew its successful maiden flight on January 8, 2024.<ref>{{Cite news |last=Belam |first=Martin |date=2024-01-08 |title=Nasa Peregrine 1 launch: Vulcan Centaur rocket carrying Nasa moon lander lifts off in Florida – live updates |url=https://www.theguardian.com/science/live/2024/jan/08/nasa-peregrine-1-launch-rocket-moon-latest-news-updates-live |access-date=2024-01-08 |work=the Guardian |language=en-GB |issn=0261-3077}}</ref>
*[[Interim Cryogenic Propulsion Stage]]: The Interim Cryogenic Propulsion Stage or ICPS is used for the SLS and is similar to the DCSS, except that the engine is an RL10B-2 and it is adapted to fit on top of the 8.4 meter diameter core stage with four [[RS-25]] Space Shuttle Main Engines.

=== In development ===
*[[Exploration Upper Stage]]: The Exploration Upper Stage will use four RL10C-3 engines.<ref>{{Cite news |last=Sloss |first=Philip |date=March 4, 2021 |title=NASA, Boeing looking to begin SLS Exploration Upper Stage manufacturing in 2021 |url=https://www.nasaspaceflight.com/2021/03/nasa-boeing-begin-sls-eus-2021/ |access-date=October 15, 2021 |work=NASASpaceflight}}</ref>

=== Cancelled ===
* OmegA Upper Stage: In April 2018, [[Northrop Grumman Innovation Systems]] announced that two RL10C-5-1 engines would be used on [[Omega (rocket)|OmegA]] in the upper stage.<ref>{{Cite web |date=April 16, 2018 |title=RL-10 Selected for OmegA Rocket |url=http://www.rocket.com/article/rl10-selected-omega%E2%84%A2-rocket |access-date=May 14, 2018 |publisher=Aerojet Rocketdyne}}</ref>  [[Blue Origin]]'s [[BE-3U]] and [[Airbus]] Safran's [[Vinci (rocket engine)|Vinci]] were also considered before Aerojet Rocketdyne's engine was selected.  OmegA development was halted after it failed to win a National Security Space Launch contract.<ref name="SpaceNews 2020">{{Cite web |date=2020-09-09 |title=Northrop Grumman to terminate OmegA rocket program |url=https://dev.spacenews.com/northrop-grumman-to-terminate-omega-rocket-program/ |access-date=2020-11-23 |website=SpaceNews |language=en-US}}</ref>
* [[Advanced Cryogenic Evolved Stage]]: {{as of|2009}}, an enhanced version of the RL10 was proposed to power the Advanced Cryogenic Evolved Stage (ACES), a long-duration, low-boiloff extension of existing [[United Launch Alliance|ULA]] [[Centaur (rocket stage)|Centaur]] and [[Delta Cryogenic Second Stage]] (DCSS) technology for the [[Vulcan (rocket)|Vulcan]] launch vehicle.<ref name="aiaa20096566">{{Cite journal |last1=Kutter |first1=Bernard F. |last2=Zegler |first2=Frank |last3=Barr |first3=Jon |last4=Bulk |first4=Tim |last5=Pitchford |first5=Brian |date=2009 |title=Robust Lunar Exploration Using an Efficient Lunar Lander Derived from Existing Upper Stages |url=https://info.aiaa.org/tac/SMG/STTC/White%20Papers/DualThrustAxisLander(DTAL)2009.pdf |url-status=dead |journal=AIAA |archive-url=https://web.archive.org/web/20110724230154/https://info.aiaa.org/tac/SMG/STTC/White%20Papers/DualThrustAxisLander%28DTAL%292009.pdf |archive-date=July 24, 2011 |access-date=March 9, 2011 |ref=AIAA 2009–6566}}</ref>  Long-duration ACES technology is intended to support [[geosynchronous]], [[cislunar]], and [[interplanetary mission|interplanetary]] missions. Another possible application is as in-space [[propellant depot]]s in [[low Earth orbit|LEO]] or at {{L2}} that could be used as way-stations for other rockets to stop and refuel on the way to beyond-LEO or interplanetary missions. Cleanup of [[space debris]] was also proposed.<ref name="aiaa20100902">{{Cite web |last1=Zegler |first1=Frank |last2=Bernard Kutter |date=September 2, 2010 |title=Evolving to a Depot-Based Space Transportation Architecture |url=http://www.ulalaunch.com/site/docs/publications/DepotBasedTransportationArchitecture2010.pdf |url-status=dead |archive-url=https://web.archive.org/web/20111020010301/http://www.ulalaunch.com/site/docs/publications/DepotBasedTransportationArchitecture2010.pdf |archive-date=October 20, 2011 |access-date=January 25, 2011 |website=AIAA SPACE 2010 Conference & Exposition |publisher=AIAA |quote=''ACES design conceptualization has been underway at ULA for many years. It leverages design features of both the Centaur and Delta Cryogenic Second Stage (DCSS) upper stages and intends to supplement and perhaps replace these stages in the future. ...'' |df=mdy-all}}</ref>