Space debris and the battle for space

On 10 February 2009, a decommissioned “Cosmos 2251” satellite and an operational “Iridium 33” satellite collided at an altitude of 790 km in low Earth orbit (leo), a zone heavily populated by communications satellites. The collision created two distinct clouds of more than 800 pieces of space debris—man-made objects in orbit that no longer serve a useful purpose. It was the first collision of two intact spacecraft and the fourth known accidental hypervelocity collision caused by catalogued space debris.