Raketikütuse

Raketikütuse, also known as rocket propellant, is the substance or substances used to propel a rocket engine. Rocket propellants are typically composed of fuel and an oxidizer. The fuel is the substance that burns, while the oxidizer provides the oxygen necessary for the combustion process, especially in environments where there is no atmospheric oxygen, such as in space.

There are two primary categories of rocket propellants: solid and liquid. Solid rocket propellants consist of a pre-mixed, stable compound that burns to produce hot gases. Once ignited, a solid propellant burns until it is entirely consumed. Liquid rocket propellants involve separate tanks for the fuel and oxidizer, which are then pumped into a combustion chamber where they mix and ignite. This allows for control over the thrust by regulating the flow of propellants.

Hybrid rocket propellants combine elements of both solid and liquid systems, typically using a solid fuel and a liquid or gaseous oxidizer.

The selection of a specific propellant depends on various factors, including the mission requirements, desired thrust, engine design, and cost. Common fuels include hydrogen, kerosene, and hydrazine, while common oxidizers include liquid oxygen, nitrogen tetroxide, and hydrogen peroxide. The combustion of these propellants produces high-temperature, high-pressure gases that are expelled through a nozzle, generating thrust according to Newton's third law of motion.