Earth is surrounded by 600 thousand of human-made debris. Some of them are big, some of them are the size of a hand, and most of them are smaller than a fingernail. Thousands of little plates, nuts, bolts and even gloves become a serious threat to any passing spacecraft when traveling at orbital speeds (around 25000 or 30000 km/h). How hard can be cleaning the space?

http://repo.openpandora.org/?page=detail&app=spacejunk-spacejunk-26575