9 Dec 2012


I write mostly about advertising, and occasionally science & technology when it relates to new developments such as 3D printing and Augmented Reality. And this stuff is really, really cool, and we presume with little doubt that it will emerge one day. Just look at the film Minority Report and how futuristic it was back in 2002, but yet in 10 short years, most of that technology is real today.

Most of these new technologies rely on a backbone of communication which includes a need for satellites - a lot of them. And that's not a problem right? They are so easy to build now that amateurs have started to do so, and find ways to launch them into low orbit.

Well, the Kessler Effect (or Kessler Syndrome) might change your thinking. It was proposed by Donald J. Kessler back in 1978 whilst he was a scientist at NASA. In brief, the Kessler Effect says that there will be so much 'stuff' up in orbit that eventually collisions will start to occur, and those will cause more 'stuff' to be in orbit, which will lead to more collisions...

The opposing theory of there being so much space that collisions are extremely unlikely, is now looking pretty weak when you start to look at maps that track all the satellites - and garbage - that floats around in our 'little' orbit. It is reported by the United States Space Surveillance Network (SSN) that there are some 3,000 satellites orbiting the Earth today, and a further 5,000 other man made objects (mostly garbage leftover from our space activities) up there too - and that's only the stuff over 4 inches in size!

A tiny piece of junk travelling at 20,000 MPH could destroy a satellite or the International Space Station (ISS) quite easily, or certainly puncture a hole big enough to give astronauts serious worries. And in fact, the SSN has tracked nearly 25,000 pieces of debris in its time, with most now having burnt up in the atmosphere, or fallen to Earth.

What made this all very real for me was a trip to the Science Museum in London with my kids. They were watching a video of satellites orbiting the Earth and simply couldn't believe it; and I don't blame them, if you do get to see it, it is quite astonishing what we have done in the short 60 years since Russia launched the first Sputnik.

And so I started to look into this problem, and discovered that Kessler was quite right. In February 2009, two satellites collided at over 24,000 MPH. One was an active communications device, and the other a defunct Russian Space Forces unit, deactivated back in 1995. Of deep concern is the report from SSN that over 2,000 pieces of additional space debris measuring over 4 inches were created from the impact, and a countless number of smaller pieces.

Without wanting to sound alarmist, all of those pieces are now also in orbit ready to cause the next collision, which in turn will create thousands more pieces of debris, which in turn... will prove Kessler right.

All this debris causes real concern. Space launches have to be planned around it, satellites maneuvered to avoid it, and in March of this year, one large piece caused the residents of the ISS to take shelter in their escape pod until it had passed. And we are talking about objects 4 inches small that is thousands of miles away and happen to be moving at incredible speeds, and so accurate tracking is almost impossible. Indeed, it was estimated that the two satellites in 2009 that collided would actually miss each other by 584 metres!

Some scientists are concerned that Kessler will be proved right on a grand scale, and that we will have so much debris in space soon that we will be limited in the number of satellites we can use successfully, and that manned space missions may be cancelled for several generations whilst we wait for all that garbage to burn up.

1 comment:

Anne Smith said...

I´ve always loved space! Still considering the size of space and the (still) relatively few objects that means that collisions are still incredibly unlikely and even less so for ibhabited satellites. I read somewhere that they were considering the possibility of some kind of giant space cleaning machine? Did you ever hear about that? No idea how it would work though...