Why don't satellites crash into Earth?

Answer 1

Because they're going fast enough to counteract the force of gravity. The faster you go, the longer the arc of the object's trajectory and the longer it takes an object to fall. The Earth is round. Eventually, you reach a speed fast enough that the object's trajectory follows the curvature of the Earth.

If it's a low altitude satellite, less than around 200 or 300 kilometers, the satellite will eventually crash into the Earth. The atmosphere doesn't just end at a certain point. It tapers off gradually. At lower altitudes for satellites, there's still some atmosphere, even if too thin to support any life. As thin as it is, it does cause at least a very small amount of wind resistance that slows the satellite. As it slows, its trajectory becomes shorter, with the end of the trajectory re-entering the atmosphere. Most space objects take months to years to re-enter the atmosphere since the atmosphere at that altitude is so thin.

By time you reach around 600 miles in altitude, the atmosphere is too thin to worry about atmospheric drag for most satellites and charts usually don't even list densities for altitudes over a 1000 miles. That means high altitude satellies like geosynchronous communications satellites never re-enter the atmosphere. At the end of their life, you have to fire the rockets and boost them to an even higher altitude where they won't be in the way of active satellites.

Answer 2

They do. Their trajectories can change, or were calculated with errors included. As a matter of fact one just came down over Utah, (I think that is where) just this past week. The smaller parts burn up in the atmosphere, but some of the larger parts make it to earth's surface.
Of course, this isn't what is supposed to happen. A satellite should stay in free- fall, meaning that as it falls to Earth, Earth rotates out from under it. The satellite falls forever, never reaching Earth, but still being dragged along by Earth's gravity. Sounds crazy but it works.

Answer 3

Satellites often do crash into earth, but it takes decades to do it. Here's why:

Satellites are orbiting earth in what are called "stable orbits," meaning that they are at a height where they won't fly off into space, and won't fall to the ground.

These stable orbits require that the satellites be moving fast enough, in a tangental direction, (meaning in a straight line, rather than a circle), that their speed forces the satellite outward and away from earth with exactly the same force as earth's gravity pulls them back down. So the satellites are moving fast enough that if they were even a mile farther away, they'd have enough momentum to fly away free into the stars.

It's all about the tangental speed, or "angular momentum."

If you're having problems with that, look up the word tangent in your textbook, which should provide a pretty good explanation.

Answer 4

They can and do. But most are burnt up from the heat caused by atmospheric friction.

Are you old enough to remember SKYLAB? The US had a large space station (another form of a satellite) that eventually was abandoned and finally crashed somewhere in remote Austrailia as I recall.

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Answer 5

Oh but they do crash.

It is the speed at which they orbit that keeps them up there.

However some of them are in low orbits where there is some thin atmosphere. This puts a drag on them and slows them down. They fly lower and hit more atmosphere. Eventually they crash into the atmosphere and burn up.

The high ones can stay up there forever, only the low ones fall.

Answer 6

convinced, they are going to attempt to shoot it down with a missile! The Pentagon stated the day surpassed by that it will attempt to shoot down a malfunctioning satellite tv for pc earlier it has a probability to go back to Earth and spread dangerous supplies over populated elements. The protection branch will attempt to blast the U.S.-made satellite tv for pc with a missile released from a military deliver in coming weeks earlier the satellite tv for pc re-enters Earth's environment, officials stated. they ought to attend till the area commute lands, i wager so it would not get stuck interior the crossfire or get hit by technique of any debris.

Answer 7

They have software where it calculates when it will crash, they have points of where to deploy the satellites. So when that time is due, they have to fly up there to redeploy.

Answer 8

Um hello....skylab!!

Answer 9

because