Space is getting crowded. And it's filling up with junk every time we launch a satellite. But this isn't like Earth-bound debris. It's travelling at speeds of up to 17,000 mph. This makes it extremely dangerous, not just for the astronauts living and working in space but also for modern life on Earth. Because everything we do - from making phone calls, flying planes, taking money out of the bank, to watching television or getting the weather forecast - is all run from vulnerable satellites orbiting the planet. This documentary explores the threat from space junk and joins the scientists searching for ways to clean up the debris.