Space debris, also known as “space junk,” is the collection of natural and manmade objects that orbit Earth. These objects range in size from tiny meteoroids to fragments from nonoperational satellites and spacecraft that are left to deteriorate in space. Scientists have tracked down more than 500,000 pieces of space junk that can threaten the safety of all space vehicles.
Space junk, traveling at speeds up to 20,000 miles per hour, can pose a severe threat to satellite or spacecraft. High-speed collisions from even the smallest pieces of space junk can threaten the lives of astronauts and cause serious damage to the International Space Station and other orbiting spacecraft.
Fortunately for astronauts, most space junk is located between 500 to 700 miles above Earth. Today, our manned spacecraft are between 200 to 300 miles above Earth. Even though space programs today are being designed to limit the amount of debris that can be sent into space during a launch, the amount of space junk has been increasing. With many objects flying near Earth, the resulting collisions between those objects can create even more fragments in space.
Even if we stopped launching rockets or spacecraft, the amount of space junk would remain constant for many years. The higher the altitude an object is from Earth, the longer it will take to fall to Earth’s surface due to gravity. Even then, there are fears that the material already in orbit will inevitably collide, creating even more space junk.
NASA and the Department of Defense are working together to monitor space junk. They maintain a highly accurate satellite catalog and establish ongoing guidelines for assessing the threat of collisions between space junk and spacecraft. Depending on the threat, evasive action can be taken or other safety precautions can help protect spacecraft and the people on board.
By Bryan Demapan, intern, Buhl Planetarium