Why astronauts float in space, even though gravity is still there
Is there gravity in space? How hard the Earth pulls on the space station
Most people think astronauts float because there is no gravity up there. But the space station flies only about 400 km above the ground. How hard does the Earth still pull at that height? The answer surprises almost everyone.
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1
On a summer night at the fair, Miva's phone buzzes. The space station is about to fly over. It looks like a bright star that moves fast and does not blink. Usually seven people live inside, and they float.
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2
Rono and Miva each have a reason why the crew floats. Many people would say the same.
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3
So how far away is the station? About 400 km up. If a road went straight up, a car on the highway would get there in about 4 hours.
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4
Draw the Earth and the path of the station at their true sizes, and the path almost touches the Earth. The station flies above almost all of the air, not far out in space.
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5
Gravity is the pull of the Earth, and it pulls toward the middle of the Earth. That middle is about 6,400 km under your feet. The station is only about 6% farther from it than you are.
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6
That means the pull is only a little weaker up there. If you could stand on a tower 400 km tall, a scale would still show about 90% of your weight.
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7
The Earth pulls on the station and on every astronaut almost as hard as it pulls on you. And still, they float.
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Go further
The station and the floating have official names, and space has a starting line.