Low-Orbit Cascading Collisions

Could a Space-Exploration accident occur in low-Earth orbit?

gravity, kessler, satellite, china, russia, movie, space, explorationIn 1978, Donald Kessler, a NASA astrophysicist proposed a catastrophic low orbit scenario.  What if the density of objects in low earth orbit hit critical mass, whereby a single collision could set off a runaway chain reaction? What if this endless cascade of debris rendered space exploration impossible for generations?

This scenario plays out in the film Gravity. However, the film is not completely based in fiction. At the beginning of the movie we learn that a Russian missile strike on one of its own satellites is the catalyst that sets the films’ Kessler Syndrome in motion.

While this action may seem ridiculous, something like it just happened. China destroyed one of its obsolete weather satellites, with a missile, in a demonstration of technical prowess. Today, the remnants of that demonstration are orbiting the Earth joining the vast, growing network of potentially dangerous debris.

In fact, according to Donald Kessler, as of 2012 the amount of space debris currently orbiting the planet has already accumulated to the point where his scenario is mathematically possible.

gravity, kessler, satellite, china, russia, movie, space, explorationFortunately, space-faring nations around the globe have begun to take this issue seriously. DARPA, NASA, the ESA and Switzerland’s École Polytechnique Fédérale de Lausanne (EPFL) are all developing solutions to clean up Space. Unfortunately, a test vehicle has yet to be launched.

Did intelligent civilizations capable of space-flight shackle themselves to their own worlds because of meandering space debris?  

The scenario might be unlikely in the long-term —satellites, space stations, and debris all have decaying orbits. Eventually they will burn up while re-entering Earth’s atmosphere.  

While Kessler’s Syndrome might not be our, or any worlds’, fate it might be wise to start testing and sending orbital janitors. Otherwise, an unforeseen disaster just might strike.

Also, see Gravity. I did last night and it is incredible.

Image Courtesy of Warner Bros.