liquid-propellant

Merlin is a family of rocket engines developed by SpaceX for use on its Falcon 1, Falcon 9, and Falcon Heavy launch vehicles. Merlin engines use a rocket grade kerosene (RP-1) and liquid oxygen as rocket propellants in a gas-generator power cycle.
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Author Pbroks13 Dec 1, 2018
https://commons.wikimedia.org/wiki/File:Liquid-Fuel_Rocket_Diagram.svg

A simplified diagram of a liquid-propellant rocket.

1. Liquid rocket fuel.
2. Oxidizer.
3. Pumps carry the fuel and oxidizer.
4. The combustion chamber mixes and burns the two liquids.
5. The gas put off by the reaction passes through the "throat", which aligns all the gases produced in the right direction.
6. Exhaust exits the rocket.