Earth is now surrounded by so much space junk that a leading expert on the issue has declared that we are at a “tipping point” — it may soon become too dangerous to venture into low-Earth orbit (LEO) through fear of having a manned spaceship punctured or a communications satellite trashed.
Ex-NASA scientist Donald Kessler led a National Research Council study into the orbital situation, and the outlook is grim. In Thursday’s announcement on the study’s findings, the amount of orbital rubbish “has reached a tipping point, with enough currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures.”
This is the nightmare scenario of the Space Age, and Kessler is all-to familiar with its ramifications. In 1978, when working in NASA’s Environmental Effects Project Office at Johnson Space Center in Houston, Texas, he developed what became known as the “Kessler Syndrome.”
As a space debris expert, Kessler realized that at some point in the future, after mankind has dumped all kinds of refuse, dead satellites, and nuts and bolts in LEO, the condition may be met when collisions between pieces of space junk become commonplace. After each collision, more and more pieces of debris are created, causing further collisions — a cascade effect would follow. Kessler now has the dubious pleasure of having a space “syndrome” named after him.
“We’ve lost control of the environment,” he said. And he’s not wrong — more junk is being left in orbit than ever and we have no way (yet) of removing the trash.
Although we may not be seeing the Kessler Syndrome in full-swing, there have been two recent incidents that dramatically demonstrate what’s going on above our heads.
In 2009, two satellites — a defunct Soviet-era satellite and a functioning Iridium communications satellite — smashed into one other at a relative speed of 7.2 miles per second, creating 1,700 pieces of debris large enough to be tracked from Earth. Each of those chunks of shredded satellite became more pieces of space junk to be avoided.
When you consider how big space is (even in LEO) and the vanishingly small likelihood of two spacecraft bumping into one another, you suddenly realize that it must be getting crowded up there.
However, the worst contributor to the space junk problem came two years earlier when the Chinese tested an anti-satellite missile on their Fengyun-1C satellite. The system obviously worked; over 2,700 pieces of the destroyed craft remain in orbit today.
These two incidents doubled the amount of debris buzzing around.
So what can be done?
The study doesn’t thoroughly examine the ways we might clean up our orbital neighborhood — although it does single out some ideas examined by DARPA — but it does stress that we need to act soon, before it’s too late.
Image: An artist’s impression of the space junk problem (satellites are overemphasized). Credit: ESA