Earth & Space
Why do people float in a space station?
A space picture changes Puschel’s idea of falling.
The short answer
The station, people and objects fall around Earth together. Because they fall together, they do not press on each other as on the ground and appear weightless. Gravity has not disappeared there.
An imagined Wusel scene
Puschel and Flauschi investigate
Outside, Flauschi opens a large picture book showing a space station. Puschel marvels at the floating people in the picture.
Puschel“Has Earth stopped pulling them?”
Flauschi“No. Gravity still acts. The station and the people fall around Earth together.”
Puschel“Why do they not reach the ground?” Flauschi“The station also moves sideways very fast. Its path goes around Earth.”
Puschel follows the pictured orbit with his eyes. Puschel“A continuing loop! On our meadow I prefer to keep my feet down.”
Little Wusel quiz
Does Earth’s gravity – the force with which Earth pulls on things – still act at the ISS?
Choose one answer: a), b).
- a)Yes
- b)No
Show answer
Correct answer: a): Yes Yes. The station and its contents share free fall around Earth.
What is missing from: The station simply falls straight to the ground?
Show answer
It also moves sideways very fast, so its orbital path goes around Earth.
Word help
- mass
- A property of objects, measured in grams or kilograms, that affects gravity and resistance to changes of motion.
- orbit
- The path of one body around another.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
Understand step by step
How it works – simply explained
Earth still attracts
Gravity reaches the station. Floating does not mean Earth has switched off its attraction.
Falling while moving sideways
The station falls towards Earth while travelling quickly sideways. On its orbit it continually misses the ground, circling Earth.
Everything falls together
People, floor and loose objects fall together. The floor hardly supports people as on Earth, so they appear weightless. The drawing shows shared falling, not blocked gravity.
Why a floating pen still has mass
A pen in an orbiting station floats rather than being pressed onto a table. It still has mass and resists changes in motion. The station and pen fall together in orbit, so ordinary support forces are largely absent. Floating does not mean the pen has disappeared or lost its mass.
References for this explanation: [1]
The key points again
Discovery 1
Earth’s gravity – the force with which Earth pulls on things – still acts strongly at the height of the International Space Station, the ISS. People there do not float because gravity has disappeared.
Source: [1]
Discovery 2
The station and everything inside fall around Earth together. They also move rapidly sideways. Their path curves around Earth instead of reaching the ground. This path is called an orbit.
Source: [1]
Discovery 3
The station, people and loose objects are all falling together. That is called free fall. The floor barely presses against people, so they float. This is called near-weightlessness or microgravity. Earth’s pull is still there.
Source: [1]