Orbital Trash

Humans have been shooting rockets into Earth orbit for over 50 years. Although a few satellites have perished in spectacular reentry burnings, most of them are still up there. Their number increases almost daily. Once a satellite breaks up or a bit of junk gets loose up there, it will likely stay in orbit for decades, even centuries.

NASA tracks many thousands of pieces of space junk that could cause harm by flying into orbiting satellites or even manned spacecraft. The International Space Station (ISS) has been nudged into a slightly different orbit a few times, in order to avoid colliding with some debris.

Two recent events have added thousands of additional bits of trash to Earth orbit. In January 2007 the Chinese deliberately blew up (in a well-aimed collision with a rocket) one of their own defunct weather satellites, in what appears to have been a menacing warning to other space-faring nations: “We can be fearsome in space.” That explosion alone increased orbital trash by some 20%. Then in February 2009, a US and a Russian communication satellite collided—in an astonishing coincidence. That crash added much more debris, which is still being counted.

We humans seem to be prone to trashing our environment—whether on land, sea, or air (and now space). It’s as if we think that the great outdoors is so vast that our junk will somehow get swallowed up and never accumulate. But we’re trashing our world, and it’s accumulating fast. Our landfills are filling, our oceans are getting clogged up, our atmosphere is getting inundated with too much CO2. Now space junk surrounds the planet.

Back in 1978 a NASA scientist, Donald Kessler, sounded an alarm about orbital trash. He described (30 years ago!) an ever-increasing accumulation of litter that can get out of hand and begin to cause a cascading number of collisions out there. The US-Russian satellite accident may be an augur of things to come. Kessler warned that all that junk may eventually become so plentiful as to shut down space flights for generations. His ominous scenario is known as the Kessler Syndrome.

The major current concern about space litter is a calamitous collision with a space shuttle or with the ISS. A tiny piece of metal the size of your thumbnail can wreak lots of damage, when it smashes into your spacecraft at 15,000 mph. Close examinations of returning space shuttles have revealed small dents and holes from minuscule bits of space trash. What can be done about the accumulation? No technology that we now possess can vacuum the stuff up.

Will the problem continue to increase, to the point of completely stopping space launches? Will we wake up and quit trashing space, before it goes that far? Or will we follow the same path we have with global warming—ignoring the problem until it’s out of control? Tune back in, in a generation or so, for the answers.