There are strict rules about how you can get rid of your old appliances on this planet, and it would certainly be frowned upon if you just opened your door and tossed out your old fridge freezer. The same cannot be said in space, however.
On the record, NASA says that it likes to minimise the amount of junk it deposits into space, but the reality is that sometimes the only thing to do with equipment is to toss it away. In recent years, for example, ABC News reported how astronauts based on the International Space Station took out their rubbish by throwing it out into space. Clay Anderson used his very first spacewalk to toss away a camera mount weighing 212 pounds and an ammonia tank which weighed no less than 1,300 pounds.
At NASA's Disposal
He perched himself at the end of the International Space Station's robotic arm and then simply threw away the unwanted equipment as he was orbiting the Earth 220 miles over the south Atlantic. At the time, he promised Mission Control that he would be mailing them a bill for his ‘space trash disposal’ services.
NASA does try to keep down the amount of trash it gets rid of into space, but sometimes there are few other options, especially when huge items are involved. There are questions that need to be answered before something can be tossed overboard, however, including whether it would be safe for the astronauts and the space station, whether it would pose a risk for other orbiting vehicles and whether it would pose any potential danger for the Earth and the people on it.
The practicalities also have to be considered. In the case of Anderson and his Russian comrade Fyodor Yurchikhin, it certainly took a bit of planning and agility to get rid of the equipment that wasn’t needed anymore. It is believed that the tank tumbled away from the International Space Station at a rate of around three feet a second.
The Biggest Trash Can in the Universe
There is a long history of space junk being thrown out into the abyss, and many of the items would make even a huge commercial refrigeration unit look like a speck of dust. In 2006, an unwanted spacesuit was packed with rubbish from the space station and cast off, along with its own transmitter. You can read about SuitSat at http://science1.nasa.gov/science-news/science-at-nasa/2006/26jan_suitsat/, and it is believed that a newer version is now being developed. This item joined an estimated 13,000 items of junk, each one measuring in excess of 30 feet long, currently orbiting in space.
It is thought that there are another 100,000 smaller pieces of trash, measuring from one to ten centimetres, along with millions of other even smaller pieces orbiting right now. This may not seem that much considering the vastness of space, but it would take just one small object travelling at thousands of miles per hour to cause catastrophic damage to a shuttle or the space station.