It might sound hard to believe but after only a few decades of space exploration, we have already managed to fill space with junk. In fact experts are insisting that there is so much debris flying around that there is a major risk of collisions – a fact agreed upon in a major international meeting this month.
It was also agreed in a summary of the meeting that there is an ’urgent need’ to start pulling some of this unused junk out of the sky. The estimates suggest that there are now more than 30,000 objects circling the planet of more than 10cms in size. These include the bodies from rockets, whole satellites and of course a large amount of fragments and general debris. Many have been cause by collisions and impacts between various objects. The size of 10cms is noted because this is the level where they can be tracked using radar, there are most definitely many thousands more fragments of sizes slightly smaller than that.
It was held as a general consensus of opinion that the amount of debris is becoming a real concern. The suggestion is that within a decade or so then a phenomenon known as the Kessler Syndrome could occur which specifies instability in the sky. ESA have a space debris office and they are suggesting that only the removal of five to ten large redundant objects can make an impact on reducing the levels of debris. Check out their site for some great footage about these redundant satellites – however be aware you’ll need a fast connection.
There are some rules regarding debris that space operators are meant to adhere to. These are mainly concerned with low-earth objects (LEO) and state that equipment should naturally fall out of the sky within 25 years of the end of a mission. The problem is that the adherence to these guidelines was very much ad-hoc and removal was very much now needed to be placed on the agenda.
It was not suggested that the situation was untenable at the moment, however there was a very real concern that the problem could become much worse. Even removing a few objects a year would take some heavy investment and development. At the moment there is no real agreed method to complete this job but it would almost certainly require a spacecraft to be launched specifically tasked with removing redundant satellites from the sky.
There have already been some collisions between satellites and debris, and specific objects at risk are thought to be a priority for removal. There are some very interesting articles on the BBC website and some documentaries covering this issue stored on the BBC Iplayer application. It’s worth checking these out – http://thenewproxies.com/british-ip-address/ although you may require a UK IP address to access some of the content on the Iplayer if you are based outside the UK.
The other good place to check is some of the European media sites, which generally cover these sort of subjects well. The broadcaster M6 Replay based in Paris is one of those, but again you’ll need a French proxy in order to access the site and the reports.