Pratically the entire interior volume of the lower stages of rockets is fuel. This is why they have to be large: to hold enough fuel to accelerate the upper stages and carry them into orbit. The fuel may be liquid or solid. The space shuttle main engines used liquid oxygen and liquid hydrogen, which was heated back to a gaseous state just before it burned in the rocket engines.
Fuel is typically stored in rockets either as liquid fuel in fuel tanks or as solid fuel in a casing. Liquid fuel rockets have separate tanks for liquid oxygen and liquid hydrogen or kerosene, while solid fuel rockets have a solid propellant mixture in a casing. Both types of fuel storage systems are designed to be safe, efficient, and controlled during flight.
The two main types of rockets are liquid fuel rockets, which use liquid propellants like liquid oxygen and kerosene, and solid fuel rockets, which use a solid mixture of fuel and oxidizer. Liquid fuel rockets offer more control and efficiency, while solid fuel rockets are simpler in design and more reliable.
Three main types of rockets that power modern spacecrafts are liquid-propellant rockets, solid-propellant rockets, and hybrid rockets. Liquid-propellant rockets use liquid fuel and oxidizer, solid-propellant rockets use solid fuel and oxidizer mixed together, and hybrid rockets use a combination of solid and liquid propellants.
Some rockets, such as liquid fuel rockets, carry liquid oxygen (LOX) as an oxidizer in a separate tank. The LOX is then mixed with the rocket's fuel and ignited to create thrust. Other rockets, like solid fuel rockets, have an oxidizer mixed into their solid fuel composition.
The earliest rockets--i.e., those built by the Chinese as early as the 14 century--used solid fuel.
Solid rockets use solid propellant that is already mixed together and cannot be turned off once ignited, providing simplicity and reliability but less flexibility in performance control. Liquid rockets use a liquid propellant that can be precisely controlled and shut off, offering better performance and efficiency but requiring more complex systems for fuel storage, management, and engine design.
Rockets commonly run on liquid fuel, solid fuel, or a combination of both. Liquid fuel rockets use liquid oxygen and liquid hydrogen, while solid fuel rockets use a solid propellant mixture. Both types of rockets generate thrust through a controlled combustion process.
Here's a rephrasing: How are rockets powered, by fuel? Yes, that's pretty much correct.
Heavier than What?
Solid rocket fuel.
Solid fuel rockets use a solid propellant mixture, which is more stable and easier to store compared to liquid fuel rockets that use liquid propellants. Iron rockets typically refer to solid fuel rockets using iron particles as part of the propellant mixture to enhance thrust. Overall, solid fuel rockets are simpler and more reliable but lack the efficiency and flexibility of liquid fuel rockets.
Rockets are classified based on their propulsion system, such as liquid fuel rockets, solid fuel rockets, or hybrid rockets. They can also be classified by their size, mission type, and payload capacity. In addition, rockets can be categorized as launch vehicles for placing payloads into orbit or as missiles for military applications.