Unless space debris is actively tackled, some satellite orbits will become extremely hazardous over the next 200 years, a new study suggests.
There are some 20,000 man-made objects in orbit that are currently being monitored regularly. About two-thirds of this population is in Low-Earth orbit.
These are just the big, easy-to-see items, however. Moving around unseen are an estimated 500,000 particles ranging in size between 1-10cm across, and perhaps tens of millions of other particles smaller than 1cm.
All of this material is travelling at several kilometres per second - sufficient velocity for even the smallest fragment to become a damaging projectile if it strikes an operational space mission.
Two key events have added significantly to the debris problem in recent years. The first was the destructive anti-satellite test conducted by the Chinese in 2007 on one of their own retired weather spacecraft. The other, in 2009, was the collision between the Cosmos 2251 and Iridium 33 satellites.
Taken together, these two events essentially negated all the mitigation gains that had been made over the previous 20 years to reduce junk production from spent rocket explosions.
Via Dr. Stefan Gruenwald