There are about 25,000 human-made objects larger than your fist flying around in orbit, and about half a million pieces bigger than a dime. If you include millimeter-scale shrapnel, the number of rogue bits reaches deep into the millions. Typical speeds in low-Earth orbit are about 30,000 kilometers per hour (18,000 miles per hour), ten times the velocity of a rifle bullet.
Once a piece of junk is identified, the laser would blast it out of orbit and into Earth’s atmosphere, where it would burn up and never hit the ground.
The researchers behind the project announced in April that they plan to deploy a small-scale proof of concept on the International Space Station, and if that’s successful, they’ll build a bigger system that would be able to zap trash within a roughly 65-mile radius.