"Apart from some tiny areas where cleaning is mandatory (e.g. our own orbit" Very true, and may I add this: http://www.bbc.co.uk/news/science-environment-14763

"Apart from some tiny areas where cleaning is mandatory (e.g. our own orbit" Very true, and may I add this: http://www.bbc.co.uk/news/science-environment-14763668 http://www.bbc.co.uk/news/science-environment-14763668 Basically, we're going to have a lot of cleanup problems in the very near future with Earth's orbit.