When mankind puts an item in earth orbit, do all of their orbits decay and eventually fall back to earth?

Answer 1

Yes. Even though the item in orbit is in the "vacuum" of space, there is still some resistance (drag) to its momentum. This drag can be caused by a thin atmosphere (planetary orbit), solar storms, space dust, micro meteors, etc. Over time, the resistance adds up in the form of orbital decay. What goes up, must come down.

Second Edit: Someone later spoke of Lagrange points as providing stable orbits. This is not true and is only a mathematical construct. Because of the size and mass of any object, like a satellite, there is not possible way that you could ever place it in orbit so that it always travels around an infinitesimally small center of gravity at an infinitesimally small point is space--i.e., a Lagrange point. Fact is, given enough time, all orbits decay!

Answer 2

no, some orbits are stable some are put on trajectories that will after the lifetime of the satellite it will naturally fall to earth.
Some satellites that were in a stable orbit are propelled by onboard thrusters into what is termed a "graveyard orbit" which means a satellite is intentionally put into an orbit that will bring it down into the atmosphere.
Satellites act the same way as the moon orbits in nature. The moon is in a stable orbit and has been for billions of years and will continue so and satellites if put in a stable orbit will do so the same, it is the same physics. Geostationary satellites (those in orbit 36000 km from Earth) are those that can potentially stay in orbit for countless years.

Answer 3

No, think of the Moon! It never falls to Earth, nor does a satellite that is high enough.

It depends on the distance from the Earth. There is still a small amount of air in space (since the atmosphere does not just abrubly stop somewhere, but gradualely tapers off). A satellite in low Earth orbit is gradually losing speed due to friction between the satellite and the faint wisps of the remmants of the Earth's atmosphere; as it loses speed, it comes closer to the Earth; as it comes closer to the Earth, the satelite encounters more (denser) air, which slows it down even more. Eventually it loses so much speed that it falls to Earth.

Answer 4

Hi. Most orbits decay due to very slight astmospheric drag. Very high orbits decay more slowly. Your question was do ALL there orbits decay and the answer is no. There are orbits that are stable. These involve Langrage points, points in space where an object is influenced by two larger bodies. In our case these are the Earth and the Moon. Objects in the Langrange points maintain stable positions. Hope this helps!

Answer 5

Only if they are in low Earth orbit. The decay is due to tiny amounts of friction with the thin upper atmosphere. If the satellite is way high then it is completely out of even the thinnest traces of the atmosphere and the orbit will not decay. Geosynchronous satellites are in this category, too high to decay. Operators of such satellites save some fuel so that they can be pushed into slightly different orbits (called graveyard orbits) when their useful lifetime is over, to get them out of the way.

Answer 6

In most cases, yes. Low Earth Orbits decay fairly rapidly due to air friction. Solar flares cause the Earth's atmosphere to swell a bit and rise, which causes air friction at higher elevations, and helped bring Skylab down earlier than expected. Geosync orbits are very high (25000 miles) and will most likely last thousands to millions of years since there's very little drag there. Lagrange points can be used to offer stable points, but some of them are "troughs" (truly stable) and some are "humps" (balanced gravity between the moon and Earth, but requires station-keeping by the satellite to stay on the hump). There are 5 Lagrange points, and I don't believe we have satellites in any of them.
There are also solar winds to contend with, since they can push a satellite out of position, forcing it away from Earth. However, Robert Forward wrote about a "statite" satellite that balances the force of the solar wind against the force of Earth's gravity to keep a satellite in a stationary position above the poles, somewhat like using the solar wind with a solar-sail.

Answer 7

yes and no. As a satelite or any other item orbits the Earth, it draws closer and closer to the Earth with each rotation due to the Earth's gravity. It will eventually fall out of orbit but most of it will burn up into the atmosphere if it's planned right.

Answer 8

Yes they will eventually all decay, but some take a really long time. Since there is no atmosphere in space there is relatively no friction on the satellite, but there is some in the form of cosmic rays, gamma rays, x-rays, etc.

Some satellites they let decay and fall back to earth, and others have their orbits corrected once in a while to get them back on track.

Answer 9

Eventually, but some of them stay up in orbit for a long time. There are a number of dead satellites circling the globe as we speak (so-called space junk).

Answer 10

There are 2 kind of orbits:stable and unstable.From an unstable orbit the body fall down to a stable one,if it is.If not,the body may fall down in time.