Mid-Space Collision - We Can't Say We Weren't Warned

This article was first posted on October 14, 2006. I brought it back because today it finally happened - a major collision between an American and a Russian satellite resulting in an explosion that launched hundreds of bits of space shrapnel into a heavily used satellite band in low orbit. From Reuters:


Space officials in Russia and the United States were on Thursday tracking hundreds of pieces of debris that were spewed into space when a U.S. satellite collided with a defunct Russian military satellite.

The crash, which Russian officials said took place on Tuesday at about 1700 GMT above northern Siberia, is the first publicly known satellite collision and has raised concerns about the safety of the manned International Space Station.

The collision happened in an orbit heavily used by satellites and other spacecraft and the U.S. Strategic Command, the arm of the Pentagon that handles space, said countries might have to manoeuvre their craft to avoid the debris.

The U.S. Joint Space Operations Center was tracking 500 to 600 new pieces of debris, some as small as 4 inches (10 cm) across, in addition to the 18,000 or so other man-made objects it previously catalogued in space, he said.Russian Space Forces said it was monitoring debris that was spread over altitudes between 500 km (310 miles) and 1300 km (807 miles) above earth.

The priority is guarding the International Space Station, which orbits at 220 miles (350 km), substantially below the collision altitude. One Russian and two U.S. astronauts are currently aboard the station.




For years we've been living with the risk of cascade. The feared phenomenon called the "Cascade Effect" refers to what may, perhaps inevitably will, happen when space junk collides.

There is all manner of debris orbiting earth. Bits of old rockets, satellites old and new, space stations and random stuff that has fallen off all of these. The material is all over the place and - here's the problem - it's all going at speeds of up to 20,000 miles per hour. At those speeds, a bolt-sized object ploughing into a satellite will probably blow that device into hundreds of bits, each of them in turn launchd in some skewed orbit. The odds are other space vehicles will start getting hit, transforming them also into hundreds or thousands of destructive bits of debris. Once this begins it won't take long for the satellite systems to be destroyed.

Right now, the cascade effect is a threat but no immediate certainty. There is even talk about developing the equivalent of a space janitor to go around sweeping up these items and rendering them harmless. However, for all the talk, these programmes aren't being funded and so they remain theoretical.

So,who cares? You ought to care and, if you don't, try learning more about this problem. Our societies are dependent on our satellite networks. We need them for our security. We need them for our science and research. We need them for our very communications. They guide our aircraft and our ships. They enable us to respond quickly to downed aircraft. They help us predict weather catastrophes.





We've become utterly dependent upon a functioning space technology system to the point where, if it went down, we don't have effective, terrestrial backups.

Maybe we'd could just put up new satellites, right? Sorry, no. The junk fallout of a cascade pretty much stays up there for many, many years and that would make space unusable for a couple of decades.

Right now the Cascade Effect is something we need to address while we still have time. The last thing mankind needs is to develop ways to make it a certainty.