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Space & Transportation

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How does a rocket work?

Hot gas shoots out of the engine, creating the thrust that lifts the rocket.

⏱ 10–15 minute exploration🎓 Middle school level🛠 Aerospace engineering
Complete the quiz at the bottom for a surprise!

Your SimpleSci lab

Getting the moving parts ready…

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Someone had to figure this out

Aerospace + propulsion engineer

Rocket engineers design engines that make strong thrust without making the rocket too heavy.

Your turn: If you could improve one part, what would you change and why?

Find this interesting? Maybe you should be an aerospace or propulsion engineer when you grow up!

1. A rocket carries its own fuel and oxidizer

This rocket carries two liquids: fuel and an oxidizer. The oxidizer is a chemical that lets the fuel burn without using oxygen from the outside air.

2. Burning propellants makes hot gas

The fuel and oxidizer meet in the combustion chamber, where they react and make very hot, high-pressure gas.

3. The nozzle speeds the gas downward

The nozzle directs the hot gas out of the engine at high speed.

4. Exhaust down means rocket up

The engine pushes exhaust downward. The exhaust pushes back on the rocket, creating an upward force called thrust. The rocket lifts off when thrust is greater than its weight.

5. The rocket gets lighter as it flies

As the rocket uses propellant, it loses mass. A lighter rocket is easier for the same engine to accelerate.

6. Stages drop empty parts

Many rockets drop empty tanks and engines during flight. Getting rid of unneeded weight helps the remaining rocket accelerate.

Think like an engineer: Pick one part. What would happen if you made it lighter, stronger, or more efficient?

4 · Quiz

Does it make sense now?

Answer all five questions. Your best score is saved on this device.

1. What creates the upward thrust on a rocket?

2. Why does a rocket carry an oxidizer?

3. What happens in the combustion chamber?

4. What does the nozzle do?

5. What must happen for the rocket to lift off?

One big idea. Now it makes sense.

Ready to explain it to someone else? Mark this exploration complete, then follow your curiosity to the next one.

What will you figure out next?