<http://schema.org/about>
"There is so much junk in space that collisions could start to increase exponentially, leading to a continuously growing pile of rubble in orbit, a new report wa"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/space/stories/report-says-space-debris-past-tipping-point>