Listened to a program on Oz radio about space junk - don't worry, there's many thousands of pieces of it floating around in various orbits. Apparently the potential for major damage to existing in-use satellites is very high. There are clever people trying to find ways to clear some of the debris up there, like giant sails that can capture junk and then close like a string bag. It's a bit like junk up on Everest left behind by littering thrill seekers, just that the stuff floating 'up there' is genuinely dangerous pollution, not just unpleasant pollution.