Russia's latest interplanetary attempt to launch a science mission to Mars has just burned-up on re-entry into Earth’s atmosphere this weekend (15th January, 2012). Maybe it should have come back down on Friday the 13th but that isn’t an unlucky day or number in Russian. Nonetheless, with a 13.2 metric ton mass, Phobos-Grunt was a heavy piece of space junk and it was full of noxious fuel for its planned trip to Mars and back. Check out the surreal YouTube video below, which is a telescope view of Phobos-Grunt as the atmosphere heats it a few days before it came back down to Earth.
As it re-entered the atmosphere the spacecraft gets superheated by molecular air friction and tumbles as it starts to burn-up and releases ablated (burnt off) particles. What’s left is a whole bunch of small particles and a couple of big ones, some of which make it back down to Earth, most likely in an ocean, but the others drift slowly down, a veritable garbage trail of destruction and a bit like following a garbage truck on the highway that doesn’t have a net over the trash it is carrying.
It is the left-over space junk that is the main worry, and CBC (Canada) just published online some really thought-provoking factoids (to go with the orbital micro-meteoroids that are the floating space junk). Check out an earlier GreenMuze article too – Unknown Facts About Space Junk.
Apart from spent rocket casings, some non-operating spacecraft, and the occasional US$100,000 (€78,500) Space Station tool bag (lost during a 2008 space walk), lots of bolts, paint flakes, and mangled hardware is speeding around at 28,800 km/h (17,900mph) in orbits up to 2000kms (1,242 miles). So launching a rocket through the debris is a little risky, and having a satellite (or space station) operate there is quite risky.
The International Space Station is going to be the biggest human piece of space junk yet, and weighing in at 417,000kgs (417 metric tons, 460 US short tons), it could come down around 2020, especially if Russia keeps on having problems launching re-supply rockets to it. The quantity of space junk is growing annually by 2-5%, due to more launches, the occasional stupidity of shooting down satellites (China, 18th January, 2007, which created more than 900 chunks of space junk), and when debris bumps into itself and shatters into smaller pieces.
There are over half a million pieces of junk bigger than 1cm (0.4inch), and 2,300,000kgs (2,300 metric tons, 2,535 US short tons) is in low earth orbit, and 6,300,000kgs (6,300 metric tons, 6,944 US short tons) up to geostationary orbit. 90% of this mass is junk, only 10% of it constitutes working satellites.
According to NASA, only one piece of debris leaves orbit per day, so the problem isn’t going to get any better, although there is only a one in-a-trillion chance of being hit by debris. Unless you are a Siberian, in which case you may want to reinforce your roof when satellites are launched from Plesetsk Space Center in northern Russia. When a recent launch went wrong, a 5kg (11lb) titanium fuel tank went through a man's roof, in (Tobolsk, Ordyn). Thankfully, he was downstairs at the time the tank destroyed his roof.
Via CBC
Trevor Williams is a University of Victoria Mechanical Engineering PhD candidate specializing in renewable energy, power grid modeling and plug-in hybrid electric vehicles. He has a bachelors in Aeronautical Engineering, a Masters in Management Science and over 23 years international experience in the space industry, having worked on Earth observation and telecommunications satellites. He is the author of the Eco-Geek blog.
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