thumb|An LR105 Atlas sustainer engine on display at the Air Zoo. The LR105 is a liquid-fuel rocket engine that served as the sustainer engine for the Atlas rocket family. Developed by Rocketdyne in 1957 as the S-4, it is called a sustainer engine because it continues firing after the LR89 booster engines have been jettisoned, providing thrust during the ascent phase.
thumb|An LR105 Atlas sustainer engine on display at the Air Zoo. The LR105 is a liquid-fuel rocket engine that served as the sustainer engine for the Atlas rocket family. Developed by Rocketdyne in 1957 as the S-4, it is called a sustainer engine because it continues firing after the LR89 booster engines have been jettisoned, providing thrust during the ascent phase.
== Description == The LR105 is a liquid-propellant engine using RP-1/LOX. The engine operates on a gas-generator cycle, where a small portion of the propellant is burned in a gas generator to drive the turbopumps, which supply the engine with fuel and oxidizer.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).