Today is the 60th anniversary of the launch of Sputnik, the first human-created object to be successfully placed in an orbit around the Earth. Since the Russians achieved the feat, humans have taken to putting stuff in space with vigor.
There is a lot of space in, er, space. And, yet, there is enough junk up there now that it’s become a serious concern for future spacecrafts. The most recent count of just how much trash we’ve put in space comes from the US Strategic Command (pdf): As of Jul. 5, 2016, there are 17,729 artificial objects in orbit above Earth, including 1,419 operational satellites. And those are just the objects large enough to be tracked.
For the rest, we only have an estimate. According to the European Space Agency, there are 29,000 pieces of human-generated debris floating out there that are larger than 10 centimeters, 670,000 bits larger than 1 centimeter, and more than 170 million larger than 1 millimeter. An impact with any of the 670,000 bits that are larger than 1 centimeter could disable the International Space Station.
All the stuff humans have left in space weighs about 5,000 metric tons altogether—roughly 1,000 kilos of trash for every launch since Sputnik. For comparison, that’s how much 10 newborn baby African elephants (or two mid-sized adults) would weigh.
The good news is that we’ve begun to work on reducing the impact of the debris. The first is to track as many of these particles as we can. The second is to find ways of taking as many of them out of orbit as possible. Both require technological solutions, but we’re still lagging in our effort to tackle the problem full on. A 2011 US National Research Council report warned NASA that the level of space debris had “reached a tipping point, with enough currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures.”