Rocket fuel facts for kids

Rocket propellant or rocket fuel means fuel for rockets. It may be in the form of solid, liquid or gas. Most rockets are chemical rockets propelled by fire. Most chemical rockets use two propellants: a fuel and an oxidizer. Think of it like this: the fuel is the wood, and the oxidizer is the match that lights it. Together, they create a big, powerful fire that sends the rocket soaring!

The Space Shuttle had solid fuel boosters with powdered aluminium as fuel and ammonium perchlorate as oxidant. The Space Shuttle main engines used liquid hydrogen as fuel and liquid oxygen as oxidant.

A toy water rocket uses a gas, such as compressed air, as a propellant.

Types

There are two main types of rocket fuel:

1. Solid rocket fuel: This type is like a giant, hard block of fuel. It's made of a mixture of solid ingredients that are packed together. Once you light it, it burns until it's all gone. Solid rocket fuel is simple and powerful, which is why it's often used for boosters – the rockets that help lift the main rocket off the ground.
2. Liquid rocket fuel: This type is made of liquid ingredients that are stored in separate tanks. When it's time to launch, the liquids are pumped into a combustion chamber where they mix and burn. Liquid rocket fuel is more complex than solid fuel, but it allows engineers to control the engine's thrust (how much power it produces) and even turn the engine on and off.

Common rocket fuels and oxidizers

Let's look at some of the most common fuels and oxidizers used in rockets:

Fuels

• Kerosene (RP-1): This is a refined form of kerosene, similar to what's used in jet engines. It's relatively cheap and easy to handle, making it a popular choice for many rockets.
• Liquid hydrogen (LH2): This is a very lightweight and powerful fuel. When it burns with oxygen, it produces only water vapor, which is good for the environment. However, it needs to be stored at extremely cold temperatures, which can be tricky.
• Methane (CH4): Methane is another promising fuel that's becoming more popular. It's cleaner-burning than kerosene and can be easier to handle than liquid hydrogen.

Oxidizers

• Liquid Oxygen (LOX): This is the most common oxidizer. It's very powerful and relatively easy to store.
• Nitrous Oxide (N2O): You might know this as "laughing gas" from the dentist's office! It can also be used as an oxidizer in rockets, especially smaller ones.
• Hydrogen Peroxide (H2O2): This is a strong oxidizer that can be used in both liquid and solid rocket fuels.

How rocket fuel works

The magic of rocket fuel happens in the rocket engine's combustion chamber. Here's how it works:

• Mixing: The fuel and oxidizer are pumped or fed into the combustion chamber.
• Ignition: A spark or another ignition source starts the burning process.
• Combustion: The fuel and oxidizer react together, creating a rapid and powerful explosion. This explosion produces hot, high-pressure gases.
• Exhaust: The hot gases are forced out of the back of the rocket through a nozzle. The nozzle is shaped to accelerate the gases, creating thrust.
• Thrust: Thrust is the force that pushes the rocket forward. The faster the gases are expelled, the more thrust the rocket produces.

Dates and figures

• 1926: Robert Goddard, an American scientist, launched the first liquid-fueled rocket. It used gasoline as fuel and liquid oxygen as an oxidizer.
• World War II: The German V-2 rocket, designed by Wernher von Braun, was the first long-range ballistic missile. It used liquid oxygen and alcohol as fuel.
• 1960s: During the Space Race, the United States and the Soviet Union developed powerful rockets using liquid hydrogen and liquid oxygen to send astronauts to the Moon.
• Saturn V: The Saturn V rocket, used for the Apollo missions, was the most powerful rocket ever built. It stood 363 feet (110 meters) tall and produced 7.6 million pounds (34 million newtons) of thrust at liftoff!
• Space Shuttle: The Space Shuttle used solid rocket boosters to help lift it into orbit. Each booster contained over 1 million pounds (450,000 kilograms) of solid propellant.
• SpaceX Falcon 9: This modern rocket uses kerosene (RP-1) and liquid oxygen. It's partially reusable, which helps to lower the cost of space travel.
• SpaceX Starship: This is a fully reusable super heavy-lift launch vehicle under development by SpaceX. It is designed to be the world's most powerful launch vehicle ever developed, with the ability to carry in excess of 100 metric tonnes to Earth orbit.

Fun facts about rocket fuel

• Some rocket fuels are so powerful that they can burn through metal! That's why rocket engines are made of special heat-resistant materials.
• Rocket fuel can be very dangerous. It's important to handle it with extreme care and follow strict safety procedures.
• Scientists are always working on developing new and better rocket fuels that are more efficient, cleaner, and safer.
• The color of the flame from a rocket engine depends on the type of fuel being used. For example, a rocket using liquid hydrogen and liquid oxygen produces a nearly invisible flame, while a rocket using kerosene produces a bright orange flame.
• The amount of rocket fuel needed to launch a rocket into space is enormous. The Saturn V rocket, for example, burned about 20,000 kilograms (44,000 pounds) of fuel per second!

Future

Scientists and engineers are constantly working to improve rocket fuel technology. Some of the exciting areas of research include:

• Greener fuels: Developing fuels that produce fewer harmful emissions and are more sustainable.
• Higher performance fuels: Creating fuels that can provide more thrust and allow rockets to travel farther and faster.
• Electric propulsion: Using electricity to accelerate ions (charged particles) to create thrust. This technology is very efficient but produces less thrust than chemical rockets.
• Nuclear propulsion: Using nuclear reactions to heat a propellant and create thrust. This technology could potentially allow for very long-duration space missions.

Images for kids

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  A Delta IV Heavy during liftoff. The rocket is entirely fuelled with liquid hydrogen and liquid oxygen cryogenic propellants.

See also

In Spanish: Propelente de cohetes para niños