...into orbit eventually falls back to Earth and burns up.But two events in the past four years - a 2007 Chinese anti-satellite weapon test and a 2009 crash-in-orbit of two satellites - put so much new junk in space that everything changed...

...acknowledging the recent test of an anti-satellite weapon. The delay raises concerns...the United States tested anti-satellite weapons in the 1980s but agreed to...atmosphere. The kind of anti-satellite weapon used by China could make...