Space will be unusable in 20 years unless junk is cleaned up says expert

"Space will be unusable within 20 years unless something is done to clean up the
170 million pieces of debris orbiting the Earth and constantly growing in number.

That's the opinion of Dr Ben Greene, CEO of Space Environment Research Centre
(SERC), who today (31 May) hosted an event in Canberra, Australia, to figure out
how to clean up Earth's orbital space."

See:

http://www.ibtimes.co.uk/space-will-...expert-1624141