what fuel is used in rockets

Rockets use different types of fuel depending on the mission and the stage of the rocket. Most liquid chemical rockets use two separate propellants: a fuel and an oxidizer. Typical fuels include kerosene, alcohol, hydrazine and its derivatives, and liquid hydrogen. Many others have been tested and used. Solid chemical propellants are also used in some rockets, such as the first stage of military missiles, commercial rockets, and the first stage boosters that are attached to both sides of the liquid-fuel tank on the space shuttle. Upper stages, which mostly or only operate in the vacuum of space, tend to use the high energy, high performance, low-density liquid hydrogen fuel. Dense liquids such as RP-1, similar to kerosene, are sometimes used for the first stage but lack the high specific impulse for use in space. Other propellant considerations include ease of ignition, combustion stability, temperature, storability, reliability, toxicity, cost, and availability.