If there is gravity where the International Space Station (ISS) is located above Earth, why doesn't the space station get pulled back down to Earth?

Question

Physics

Cristian Chang

6 September, 22:23

If there is gravity where the International Space Station (ISS) is located above Earth, why doesn't the space station get pulled back down to Earth?

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Answers (1)

Know the Answer?

Camilla Bowen · Answer 1

Yes. Gravity is 90% of what it is on the earth's surface. ISS moves at such high speeds that the curve of its fall will always match the curve of the earth and so will never hit the earth.

Explanation:

The location of the International Space Station (ISS) is at an altitude of about 200 or 250 miles above the earth's surface. Since gravity decreases with altitude, it is less at that height. Gravity is still present there. Since the ISS is in orbit around the earth, the condition is of free fall. Result of this free fall is apparent weightlessness. The high speed of the ISS allows it to orbit around in such a way that the gravitational pull of the earth is equal to the centripetal force experienced by the ISS in its orbit.

The conditions which make it remain in space are similar to how the moon stays in the orbit around the earth. Moon is also in free fall but it never falls down to earth.