Space Junk: A Catastrophe On The Horizon

More and more junk is cluttering space, threatening our satellites and rockets.

- Daniel Clery

OUT IN THE BLACKNESS OF SPACE  two astronauts are repairing the Hubble telescope and enjoying glimpses of their blue planet in the distance. At the same time, Russia decides to test an anti-satellite missile. Within minutes, the debris shower takes out the space shuttle and damages the International and Chinese space stations. Will the astronauts survive?  

Many readers will recognise the plot of the movie Gravity. Fewer may know that on 10 February 2009, a real space nightmare came true. A satellite belonging to Iridium Communications relaying data to and from mobile phone users was passing over Siberia’s Taymyr Peninsula. At 16.56 GMT Iridium 33 was there; at 16.57 it was not. It had collided with a dead Russian military communications satellite. Weighing one tonne and travelling at a relative speed of 12 kilometres per second, the Kosmos 2251 satellite hit Iridium 33 with three times the kinetic energy of an Airbus A380. Both spacecraft disintegrated, scattering wreckage far and wide.

The loss of one of its 66 satellites was a blow to Iridium, but what caused sleepless nights for satellite operators and space agencies everywhere was the floating debris. The US Space Surveillance Network catalogued more than 2,000 fragments bigger than a grapefruit from the collision and a much greater number of smaller ones. At the speeds required for low-Earth orbit, an object the size of a marble can cripple a satellite or punch a hole in a space station. The Iridium-Kosmos crash did not cause the kind of devastation depicted in