1. Liquid Propellants:
a. Liquid Oxygen (LOX) and Liquid Hydrogen (LH2): This combination is widely used in rockets due to its high specific impulse (a measure of fuel efficiency). LOX provides the oxidizer, while LH2 serves as the fuel. It is commonly used in upper stages of rockets, such as the second stage of the Saturn V rocket.
b. Liquid Oxygen (LOX) and Kerosene (RP-1): This fuel combination is used in many launch vehicles, including the first stage of the Falcon 9 rocket. RP-1 is a refined form of kerosene that is specifically designed for rocket use.
2. Solid Propellants:
Solid rocket motors use a mixture of fuel and oxidizer that are cast or molded into a solid grain. The most common solid propellant is a composite of an oxidizer (such as ammonium perchlorate) and a fuel (such as aluminum, carbon, or polymers). Solid propellants are known for their reliability, simplicity, and ability to provide high thrust. They are often used in boosters and initial stages of rockets.
3. Hypergolic Propellants:
Hypergolic propellants ignite spontaneously upon contact with each other, without the need for an external ignition source. They are typically used in spacecraft maneuvering thrusters and reaction control systems. Common hypergolic propellants include:
a. Monomethylhydrazine (MMH) and Nitrogen Tetroxide (NTO): This combination is widely used in spacecraft propulsion. MMH is the fuel, while NTO acts as the oxidizer.
b. Unsymmetrical Dimethylhydrazine (UDMH) and Nitrogen Tetroxide (NTO): Similar to MMH and NTO, this pairing is also used in rocket propulsion systems.
It's worth noting that the selection of rocket fuel depends on factors such as the specific mission requirements, desired performance, safety considerations, and cost-effectiveness.
