A crash course in space junk
Pieces of man-made space junk are constantly orbiting around the Earth at speeds of up to 17,400 miles per hour. According to NASA, there are more than 20,000 pieces of debris larger than a softball, 500,000 pieces about the size of a marble, and tens of millions of microscopic pieces as small as a speck of paint.
The growing amount of debris is leading experts to conclude that this serious environmental and safety issue in space needs to be addressed. [email protected] spoke to Victoria Coverstone, professor and chair of Mechanical and Aerospace Engineering at the College of Engineering, to learn more about the problem.
Why is space littered with so much debris?
More space debris is accumulating as the planet launches more objects into space. Nothing lasts forever, and the same goes for satellites. There are many dead satellites that are stuck orbiting right now. After 20 years or so, many times a satellite runs out of fuel, leading the satellite to just drift around, causing it to potentially collide with other objects. Debris can also come from humans who travel into space. Astronauts, for example, have accidentally dropped objects as small as a screw during space walks that then float off.
Who is tracking these pieces of debris and how do they keep track of it?
Led by the U.S. military, the Space Surveillance Network has a central location that detects, tracks, catalogs and identifies objects orbiting Earth. A lot of these objects are big, but most of them are very small, so they’re hard to detect. I know our government is investing money to upgrade the sensors that detect this space debris. The goal is to update the sensors to continually get more accurate information of where the smaller pieces are located.
Why does space junk pose such a threat?
I think people are paying more attention to this problem because it could cause severe economic and safety problems if more debris keeps building up. Some of the satellites that are being launched cost millions of dollars, and if it gets hit by even a tiny piece of space debris, it could be left not operational. Another aspect is, if you’re moving astronauts into space, and a piece of debris hits a pressurized vessel, it could be catastrophic for the people onboard. The satellite that is the most monitored is the International Space Station, for obvious reasons. Thankfully there hasn’t been severe collisions, but there’s pictures of windows in the International Space Station that have dents from impacts from high velocity objects that don’t penetrate through. They’re getting hit by smaller objects very frequently. That’s why people on board the station have to maneuver often to avoid getting struck.
Are there regulations that have been put into place to reduce the amount of junk in space?
So far, NASA has put restrictions on themselves. The agency has implemented a rule that once a satellite mission in low earth orbit is complete, the party responsible for that satellite must have a plan on how to deorbit the satellite within 25 years. The only problem is that the United States can regulate ourselves and put restrictions on companies, but unless there’s an international agreement, there are other players that need to be motivated and convinced that this is a problem. Right now, there aren’t any specific international rules of what you have to adhere to when you launch an object into space. The United Nations General Assembly endorsed some guidelines for orbital debris mitigation standard practices, but these do not contain specific requirements. As far as being more sustainable, organizations are also trying to figure out how to make satellites more recyclable, but this will require a change in the design approach to building satellites.
Are there any ideas on how to remove space debris that is orbiting in space?
There’s been several ideas proposed. One of the ideas is to launch a collector satellite that has some sort of mechanism, like a net, to capture junk and bring it back to a collecting space craft. The idea is when it eventually reaches its maximum garbage potential, then it reenters the atmosphere and burns up. This will require countries to come together and form an international group and figure out who will pay for this service. It all depends on when people choose to make the decision that this is an important issue to tackle moving forward.
source: University of Miami