Technology
How do rockets work?
Rockets work by Newton's third law: they burn fuel to shoot hot gas out the back at high speed, and the equal and opposite reaction pushes the rocket forward. Unlike a jet, a rocket carries its own oxygen, so it can work even in the vacuum of space.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a rocket works.
Step by step
- 1A rocket burns fuel with an oxidizer to produce a high-speed jet of exhaust gas.
- 2By Newton's third law, expelling gas backward pushes the rocket forward (thrust).
- 3It carries its own oxygen supply, so it works in space where there's no air.
- 4To reach orbit, a rocket must accelerate to about 28,000 km/h sideways, not just go straight up.
- 5Most use multiple stages, dropping empty fuel tanks to shed weight as they climb.
Frequently asked questions
- How do rockets work in space with no air?
- Rockets don't push against air — they push against their own expelled exhaust. They carry their own oxidizer to burn fuel, so they work fine in a vacuum.
- What's the difference between a rocket and a jet engine?
- A jet engine takes in air from the atmosphere to burn fuel; a rocket carries its own oxygen, so it can operate in space where a jet engine can't.
- Why do rockets have stages?
- Dropping empty tanks mid-flight sheds dead weight, so the remaining engines accelerate the lighter rocket more efficiently toward orbit.