Imagine the space around Earth being so full of junk that objects collide with other objects, tearing them apart, creating more junk. Imagine that new junk collides with other objects, creating even more junk until all that is left in Earth’s orbit is a cloud of debris moving seven times the speed of a bullet. No satellites, no space station, no astronauts — only junk.
This was the idea behind the 2013 movie Gravity, starring Sandra Bullock. In that film, space debris from a collision between two objects collided with the astronauts’ space shuttle, creating more debris, which then collided with the space station and other objects, eventually taking out basically everything in space.
Sure, it was just a film, but aside from a handful of things the film got objectively wrong about space and science, could such a chain reaction of collisions actually happen? Scientists say yes.
In 1978, a NASA scientist named Donald J. Kessler published a theory in the American Journal of Geophysical Research that the portion of space where most satellites live, known as Low-Earth Orbit (LEO), would soon be filled with so much orbiting debris that astronauts could not safely work in space, and objects could not be sent up there. Kessler surmised that as the number of objects in space increased, the number of collisions between objects would also increase, creating an exponential expansion of space debris, until eventually we would have to abandon LEO entirely.
The effect Kessler described is now known as Kessler Effect, or the Kessler Effect. NASA calls it “collisional cascading,” and it is a very real concern.
Right now there are approximately 500,000 pieces of marble-sized space waste in Earth’s orbit, and more than 20,000 pieces are larger than a softball. Each of these pieces of junk are traveling at approximately 17,500 miles per hour, making each small piece of waste a hyper-fast bullet, capable of destroying anything with which it comes into contact.
Satellite launches, manned space missions, and every other conceivable use of space introduce objects into orbit. Some of the objects fall harmlessly into the atmosphere and “burn up” on re-entry. Most, however, remain in orbit. Everything orbiting the Earth right now, whether it is a usable piece of equipment or a piece of junk is called the “orbital population.” Less than 10 percent of the orbital population is satellites. The rest is waste.
Each year, as more satellites and manned space missions are launched, the orbital population grows. In 1978, when Kessler published his theory, just 21 years after the launch of the first satellite, approximately 125 satellites were put into space. Today there are over two thousand. Even if we were to cease putting objects into space today, the amount of space waste due to collisions of objects already in orbit would continue exponentially, and, due to the Kessler Effect, LEO would become unusable for generations.
Although the film Gravity presented a realistic scenario, the one major plot point it got incredibly wrong was the speed at which the Kessler Effect transpired. In the film, the effect happened over the course of a few minutes. In reality, the Kessler Effect would happen slowly, with pieces of debris spreading out from the source of a collision like an explosion in slow motion.
Aside from the speed, however, the effect was captured perfectly. Objects collided with debris, creating more debris, which collided with more objects until the whole of LEO was rendered useless. Although the film was fiction, its premise is very real. In fact, we might already be at the beginning of the Kessler Effect.
To tackle this problem of galactic proportions, Rubicon has launched Clear Constellation, a project aimed to generate new ideas for capturing space waste and cleaning up LEO.