What happens to the old satellites and other debris that is left in space? Why is it even acceptable to leave our trash / garbage out there?

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    $\begingroup$ Related question: space.stackexchange.com/questions/4859/… $\endgroup$
    – Hobbes
    Oct 28, 2015 at 18:59
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    $\begingroup$ What exactly do you mean by "acceptable"? Acceptable to whom? When? $\endgroup$ Oct 28, 2015 at 19:03
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    $\begingroup$ Potential duplicate of space.stackexchange.com/questions/4948/… $\endgroup$
    – called2voyage
    Oct 28, 2015 at 19:17
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    $\begingroup$ How about just typing your question into Google? It's not that you cannot ask that here (although these kinds of wide open questions risk getting 'too broad' close votes), but Googling What happens to the old satellites and other debris that is left in space gives nearly 6 million hits and you have your answer immediately. $\endgroup$
    – user10509
    Oct 29, 2015 at 13:40
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    $\begingroup$ Possible duplicate of Space debris half life $\endgroup$
    – kim holder
    Oct 30, 2015 at 18:37

2 Answers 2


Once something is in space, there's only a few ways it'll ever come back down.

  1. It rockets down to re-enter Earth
  2. It is in the upper part of the atmosphere, which slowly will bring it down.
  3. Sunlight pushes it into an orbit where it intersects the atmosphere, or even leaves Earth orbit.
  4. It hits another object, changing it's velocity.

Once debris is up there, it's hard to get down. Spacecraft are required to put themselves into either a graveyard orbit, or an orbit where the spacecraft will naturally return to Earth shortly thereafter. However, some spacecraft fail, others were built before this was a known problem, and overall, it's expensive to ensure that it happens.

  • $\begingroup$ If I get it correctly, boulders on the Moon are pulverised by (micro)meteoroids over time and are thus only present where they formed near young craters. Shouldn't spacecrafts in cis-lunar space be similarly pulverized over time? $\endgroup$
    – LocalFluff
    Oct 30, 2015 at 11:12
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    $\begingroup$ It happens anywhere in the Solar System actually. That basically falls under the "It hits another object" category. $\endgroup$
    – PearsonArtPhoto
    Oct 30, 2015 at 12:00

Currently there are thousands to millions of objects orbiting around earth's surface. These items are just as "acceptable" as Saturn's rings. Whether everything will stay there or come down to earth depends on the object.

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    $\begingroup$ It's not exactly true that the debris in (mostly) LEO is just as acceptable as Saturn's rings; the rings are a navigational obstacle to only a very few purpose-built probes, while the debris is a potentially rather serious threat to pretty much any continued use of space. $\endgroup$ Oct 30, 2015 at 6:45

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