Do objects in orbits remain in orbits forever? Why do some satellites fall back to earth? Is there any?

Question

aerodynamic drag in space to slow down objects in orbits?

Answer 1

Objects in orbit will, depending on mass and speed, either expand their orbit, or eventually fall back to earth, due mainly to the effect of gravity.  The solar wind and some space debris may have minimal effect, but does contribute to the eventual return of most of our manmade satellites.

Answer 2

An object will fall from orbit when the gravitational pull from Earth overtakes the inertia of the object.  This happens as the object gets too close and gravity becomes stronger than the speed of the object.

Answer 3

The atmosphere of Earth does not end suddenly, but extends up to 1500 km above the surface on solar active years.

All satellite below this limit experience a small drag, which slows them down. When the satellites slow down, their orbits first loose eccentricity and become nearly circular, then the satellites spiral deeper into the atmosphere.

Satellite above 1500 km are also not safe. Sun and Moon can change the satellite orbits slowly and can cause them to reenter the atmosphere or leave the gravity well of Earth.

The ISS looses about 30 m altitude every orbit, that's why it needs reboost maneuver to raise the orbit again and to not drop so deep into the atmosphere, that it can't get saved from burning up.

Answer 4

its  based on centrifugal or centripetal force, i am not sure which one is which ( i always get confused in this topic)

1) the force which revolves around the object towards the object is i think centripital force

2) the force which revolved around and about away from the object is centrifugal force

or maybe vise versa..

eg.. a gold chain.. attach an object to the chain and start spinning it, after a while it will disslodge and fly away

2) the moon revoling around the earth.. it revoles in it orbit but is still attracted to earth...

what you are speaking is of 2).. in order for this to happen, the object has to change its orbit by force..

and there is no aerodynamic drag in space as it is a vaccum

Answer 5

no orbit is perfect in space since there is always an effect from other bodies.  Only a perfect 2 body system can have true stability.