Why don't satellites in orbit fall to the ground? Why don't they fly off into space?

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Why don&#039;t satellites in orbit fall to the ground? Why don&#039;t they fly off into space?

anthroposmlvd · Accepted Answer

The semi-major axis distance a of an orbiting satellite&#039;s elliptical orbit and its orbital period P are related when the satellite is in orbit. The relationship is described by Kepler&#039;s third law:            P      2        ∝          a      3      The closer a satellite orbits the planet, the shorter its period must be to keep it in orbit and the faster it is travelling.A satellite&#039;s orbital period lengthens if it uses a rocket engine to slow down, leaving it out of orbit and beginning to fall. It gains speed as it descends through gravity. The satellite will move into a lower orbit with a shorter period once the orbital period and distance are once again in balance.If the satellite falls low enough and at a steep enough angle, the atmosphere will continue to slow it down and it will fall to the ground. This is how orbiting space craft are landed.If a satellite fires a rocket engine and speeds up, then its orbital period reduces and it starts to fly off into space. As it gets higher, gravity slows it down. When the orbital period and distance are again in balance, the satellite will assume a higher orbit with a longer period.If the satellite fires its rocket for long enough it will be travelling to fast for gravity to slow it into an orbit. In this case it will fly off into space. This is how we get space craft to the Moon and other planets.This is a interactive webpage for the experimentation of satellite&#039;s orbit.

Why don't satellites in orbit fall to the ground? Why don't they fly off into space?

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