Tracking Space Trash
(Inside Science) -- When you look up at the sky on a clear night, you might be able to see stars, and a planet if you’re lucky. But what you don’t see is all the space junk that’s up there floating around and orbiting earth.
Most of it is useless bits and pieces of things like nonfunctioning space rockets, abandoned launch crafts and old satellites that no one cares about anymore. However, this space trash is traveling over 17,000 miles per hour, plenty fast enough to do serious damage to working satellites and the International Space Station. NASA and the Department of Defense are keeping an eye on the debris, but now MIT researchers are helping the tracking efforts with a cool laser.
There are more than 20,000 pieces of space junk larger than a softball orbiting the Earth. There are over 500,000 pieces of debris the size of a marble or larger. And there are many millions of pieces of space trash that are so small they can’t be tracked.
Michael Pasqual, from the Massachusetts Institute of Technology, said, “Even tiny flecks of paint can damage a spacecraft when traveling at such high speeds. In the past, windows on the space shuttle have been replaced because of damage caused by paint flecks.” He has been watching this mounting problem.
“Even a piece of debris as small as a baseball could completely torpedo a satellite and destroy it,” said Pasqual.
The U.S. already uses telescopes and laser radars to keep an eye on the growing number and location of the debris.
Now, engineers at MIT are using a technique called laser polarimetry to help with the space trash tracking mission. It can identify what the junk is made of, and help determine its mass and where it came from. The information could help NASA predict damage-causing impacts and move satellites out of the way.
Right now, the International Space Station is the most heavily protected spacecraft. It can withstand impacts from debris about one centimeter in diameter. If the pilots know a larger object is headed their way, they can move to avoid it. Laser technologies can help identify that bigger, damaging space junk.
“We care a lot about difficult space problems, and space debris is one of the most critical problems that the country and the world will face in the near future, and applying very exciting technologies with lasers, there’s a lot of potential there to tackle this difficult problem,” concluded Pasqual.
