Sunday, June 13, 2010

The Kessler Syndrome

I am not making this up. There really is a Kessler syndrome. An article in Wired Magazine for May 24 explains that there is a lot of space junk such as dead satellites, live satellites, pieces of rockets, and general space debris accumulating in orbit around the earth.

In 1978 a NASA astrophysicist named Donald Kessler (no relation) predicted that as the number of things in orbit went up the likelihood of collisions between them would go up exponentially (actually combinatorily which is much faster, but who's counting?). Since all the stuff in orbit is moving fast fast fast, when it runs into other stuff in orbit, the impact is at several miles per second. Both objects shatter into lots of other objects. Which quickly increases the number of things in orbit with a potential to crash into one another. It becomes a runaway chain reaction in which the earth becomes surrounded by a debris cloud.

In that seminal paper, “Collision Frequency of Artificial Satellites: The Creation of a Debris Belt,” Kessler painted a nightmare scenario: Spent satellites and other space trash would accumulate until crashes became inevitable. Colliding objects would shatter into countless equally dangerous fragments, setting off a chain reaction of additional crashes. “The result would be an exponential increase in the number of objects with time,” he wrote, “creating a belt of debris around the Earth.”

His description of a runaway cascade of collisions—which he predicted would happen in 30 to 40 years—became known as the Kessler syndrome.

That chain reaction is the Kessler syndrome. It has just started.

On February 10, 2009—just a little more than three decades after the publication of his paper—the Kessler syndrome made its stunning debut. Some 500 miles over the Siberian tundra, two satellites were cruising through space, each racing along at about 5 miles per second. Iridium 33 was flying north, relaying phone conversations. A long-retired Russian communication outpost called Cosmos 2251 was tumbling east in an uncontrolled orbit. Then they collided. The ferocious impact smashed the satellites into roughly 2,100 pieces. Repercussions on the ground were minimal—perhaps a few dropped calls—but up in the sky, the consequences were serious. The wreckage quickly expanded into a cloud of debris, each shard an orbiting cannonball capable of destroying yet another hunk of high-priced hardware.
Note that 2 things in orbit became 2100 things in orbit. The cosmic crap is beginning to hit the cosmic fan. The Kessler syndrome is upon us.


  1. Nick Danger1:53 AM

    Perhaps this is how planetary rings are formed, except that on planets without human space junk the original source of the debris might be fragments of moons ripped apart by tidal forces.

  2. Anonymous6:11 AM

    If one wanted to be tuly contemporary it would have to be "Kessler's kosmic krap...". Alliteration and spelling are very important in this doomed world. :<)