australia to clean up space junk

[nathj]

i was angry when i read this, how about we get a space program before we help to clean up other countrys spac garbage,

[ATTITUDE]

we have been cleaning up other countries garbage for years.......boat people for one.

[Tradesman]

couldnt download that article , just how do they intend to clean up space junk? doesnt it all just fall back to earth and vapourise over time? not sure

[trash]

It doesn't quite work that way.
If an object's orbit is low enough, atmospheric drag will slow it down over a long enough period of time and its orbit will decay to the point where it re-enters the atmosphere.
The larger the surface area of the object with respect to its mass, the quicker it will de-orbit.
But there comes a point where there will never be enough atmospheric drag to slow the object down and so it will become a permanent resident in orbit. In some cases tidal effects of the sun and the moon combined with the solar wind will alter the orbit and then it will be influenced by atmospheric drag or flung out of orbit. This takes a very long time.

Basically what Hilary is suggesting is that rather than chucking the styrofoam containers out of the window of the space shuttle, the yanks are going to try and drive them to the next road stop and put them in the bin.

If we think of a standard geo-sync satellite going into orbit then all of its components need to be accounted for. The first stage of the booster is dumped and quickly falls back to earth. Sometimes it is recovered and other times it burns up.
The second stage is next. It gets the payload into orbit. If it is dumped, it may take several months or years to decay. As part of the efforts such a stage may carry a retro stage to help de-orbit it quicker after the payload has be separated. The cowling and components are the real problem. It's not possible to put engines on each of these items, so they need to be ejected where they will decay.
The third stage which delivers the satellite into its higher orbit then becomes the next problem. Generally this is part of the satellite itself and when the satellite is moved into its permanent orbit the engines remain attached to the satellite itself.
Finally the satellite itself becomes space junk. Before the satellite reaches the end of its serviceable life it is either de-orbited, or it is pushed out into a higher graveyard orbit. The higher the better.

What's out there already is basically impossible to clean up. While it might sound bad that there are so many objects, they are relatively small and space is very very big.
If I took all of those objects and put them in a much smaller volume or even a flat surface area like Australia, scattering them around at random they would be still very difficult to come in contact with.
The larger satellites would be more practical to de-orbit. Sending a drone to rendezvous with the satellite, attach to it and then decelerate (or accelerate) it.