I recently watched a program about space and NASA and was amazed to discover that the space agencies are tracking over 8,000 items of space debris orbiting the planet! Thinking about it, that sort of makes sense given the decades of space launches and old and broken satellites, but it was the imagery of the earth surrounded by a cloud of detritus that really shocked me:
The question is, is this really a problem? Well there was the news story a couple of weeks ago about 2 whole satellites colliding and destroying each other, the first time ever that this has happened. Add to that the fact that the international space station has to actually change its orbit regularly in order to avoid space debris. How soon will it be before a space shuttle or rocket launch is compromised by some lost bolt doing 18,000 mph? The space shuttle even suffered a cracked window due to being hit by a speck of paint! And take a look what the night’s sky looks like when you add the debris in:
I’ve wondered what the solution to this problem is, as surely sorting it out now before it gets much worse, is the right thing to do. There are 2 sources of space junk: there are thousands of old satellites that are now defunct but just left in space; then there are accidental losses, like the NASA astronaut that dropped her tool kit whilst on space walk.
The satellites should be easily fixable. The addition of a rocket or similar thrusting device should be able to shunt the satellite out of its orbit. I guess there are 2 options, but both have issues:
1) Decay the orbit so the satellite burns up in the atmosphere. I’m not a great fan of this approach as who knows what we’re contaminating the atmosphere with, and I guess there’s always the chance that some part of the satellite won’t burn up and will land on someone’s head.
2) Shoot the satellite out of orbit at the Sun. The Sun is certainly the best place to incinerate old satellites, but it occurs to me that the amount of thrust required to actually escape the earth’s orbit, might make this approach prohibitive. Actually I don’t know the numbers, but I imagine that’s so.
3) The third and by far the most complicated solution is to get some garbage disposal robotised satellites into orbit, that will track down space junk and destroy it. Of course the question is how?
It’s a tricky issue, but I do hope that the human race is capable of continuing space exploration without trashing our own orbital space and storing up a more problem for our children.