Ever since the space-race in the 1960's, we have been putting all kinds of objects into low and high earth orbit. When first launched these satellites have performed all kinds of tasks from being communication satellites to running scientific experiments. Once their use has expired or they have been damaged they essentially become space junk because there is often no way of knocking them out of orbit.
The Horizon documentary The Trouble with Space Junk narrated by David Stewart examines how much of a problem space junk is becoming. Yes space is infinite but there is only a finite amount of space on the orbital highways of Earth; the Internation Space station has already had to change it's orbit 3 times in order to avoid potential strikes from junk that is travelling at thousands of miles-per-hour. What problems is all this junk causing and how can the problem be rectified? "The Trouble with Space Junk" aims to provide some answers.
