Whyscope Question 92 Chapter 9 · How Things Work

How do rockets work?

A rocket follows a rule: every action has an equal and opposite reaction. The rocket pushes propellant out of its engine, and the propellant pushes the rocket the other way. Fuel and oxidizer burn in a chamber, and the nozzle makes the hot gas rush out even faster. A rocket carries its own oxidizer, so it works in space, where there is no air.

whyscope.org/q/92

How do we know?

↻ One of the pages with a moving picture

The first liquid-fuel rocket was launched in a snowy field.

air outEvery action hasan equal andopposite reaction1 The rocket pushespropellant out2 fuel + oxidizerFuel and oxidizerburn; the nozzlespeeds the gas3 It carries its ownoxidizer, so itworks in space4
Simplified and not to scale. The numbers match the steps below.
  1. A rocket follows a rule: every action has an equal and opposite reaction.
  2. The rocket pushes propellant out of its engine. The propellant pushes the rocket the other way.
  3. Fuel and oxidizer burn in a chamber. The nozzle makes the hot gas rush out even faster.
  4. A rocket carries its own oxidizer, so it works in space, where there is no air.

On 16 March 1926, Robert Goddard launched the world’s first liquid-fuel rocket from a snowy field near Auburn, Massachusetts.

Only Goddard, his wife Esther and a couple of helpers saw it. Esther’s film ran out, so she missed the liftoff, but she filmed the setup. It didn’t even make the local newspapers!

Goddard’s rocket burned for 20 seconds before it lifted off.

Wow number

41 feet How high the first liquid-fuel rocket flew. It landed 184 feet away.

Myth or fact?

Rockets need air to push against. Myth. Rockets push on their own exhaust, so they work in space with no air.

More air in a balloon rocket usually sends it farther. Fact. NASA says how far it goes is related to how much air is inside.

Think about it

Goddard’s rocket burned for 20 seconds before it lifted off. Why do you think it needed time to get going?

Where in the world?

Auburn, Massachusetts, USA where, on 16 March 1926, Robert Goddard launched the world’s first liquid-fuel rocket from a snowy field near here — 42.1945° N, 71.8356° W.

Where these facts come from

Every number on page 92, and who measured it

This page tells us Esther's film ran out before the rocket lifted off.

"[023] "The empty frame" after world's first flight of a liquid-propell" by Esther C. Goddard — Clark University, which keeps Robert and Esther Goddard's papers and photos
commons.clarku.edu/goddardphotographs/21

We checked it on 31 October 2026

This page tells us about Robert Goddard's 1926 rocket in a snowy Massachusetts field.

Robert Goddard and the First Liquid-Propellant Rocket — The Smithsonian's National Air and Space Museum
airandspace.si.edu/stories/editorial/robert-goddard-and-first-liquid-propellant-rocket

We checked it on 31 October 2026

This page tells us how a balloon rocket works.

Propulsion-Activity — NASA, the U.S. space agency
grc.nasa.gov/www/k-12/BGP/Shari_N/propulsion_act.htm

We checked it on 31 October 2026

This page tells us that every push has an equal push back.

Simple Rocket Science – Science Lesson — NASA's Jet Propulsion Laboratory
jpl.nasa.gov/edu/resources/lesson-plan/simple-rocket-science

We checked it on 31 October 2026

This page tells us how rocket engines push and why they work in space.

Rocket Thrust — NASA, the U.S. space agency
www1.grc.nasa.gov/beginners-guide-to-aeronautics/rocket-thrust

We checked it on 31 October 2026

Has this changed?

How rockets work is not going to change.

Rockets have changed a lot since 1926, but they still work on the same rule.

Words from this page

propellant
The stuff a rocket pushes out of its engine.
oxidizer
What a rocket carries so that its fuel can burn without air.
nozzle
The bell-shaped end of a rocket engine that makes the gas rush out faster.

Try it!

Launch a balloon rocket.

1. Thread a string through a straw. Tie each end to a chair. 2. Have a grown-up blow up a balloon and pinch it shut. Tape it to the straw. 3. Let go! Try again with less air. Throw away any popped balloon bits.

What happens: air rushes out the back, and the balloon zooms the other way along the string.

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