Explore every rocket engine subcomponent tracked on Space Launch Live. From the extreme-RPM turbopumps that feed propellant into combustion chambers, to the precisely engineered injector heads that atomize fuel and oxidizer, to regeneratively-cooled nozzles that withstand thousands of degrees — understand the engineering that makes spaceflight possible. Browse component categories including turbomachinery, combustion systems, nozzle assemblies, cooling systems, ignition devices, thrust vector control actuators, valves, and seals.

Inside a Rocket Engine

Deep-dive into the subcomponents of rocket propulsion: how turbopumps spin at tens of thousands of RPM, why the pintle injector changed engine design, and how regenerative cooling keeps a combustion chamber from melting itself.

A liquid engine is a controlled explosion held in place by a handful of hard-working parts. Turbopumps force fuel and oxidizer into the chamber against enormous pressure — SpaceX’s Merlin pump spins around 36,000 RPM, and the Saturn V F-1’s pump delivered propellant at roughly 55,000 horsepower. The injector then sprays and mixes them: the simple, throttle-friendly pintle injector first proved itself on the Apollo lunar-module descent engine and now sits at the heart of the Merlin. In the combustion chamber and nozzle, hot gas is accelerated to supersonic exhaust, with vacuum engines using tall, wide nozzle bells (the RL10, Raptor Vacuum) to wring out extra efficiency where there is no air pressure to fight.

Keeping all that from melting is its own art. Regenerative cooling routes cold propellant through channels in the chamber walls before it burns, carrying heat away and pre-warming the fuel. The chamber pressure those parts must contain spans a wide range — from Merlin’s roughly 97 bar to the RS-25’s ~206 bar to Raptor’s full-flow staged combustion above 300 bar — and the power cycle that drives the pumps (gas-generator, staged combustion, electric-pump, or pressure-fed) is one of the defining choices in any engine’s design.