NASA plans laser method for clearing space junk

A laser-based method could help sweep debris from Earth's orbit, by slowing it down until it re-enters the atmosphere and burns up.

Space junk is cluttering the high frontier. The growing cloud of debris in Earth orbit has been worrying space-faring nations for some time, but nothing in particular has been done to clean it up.

A team of scientists from NASA and Cornell University has proposed a laser-based method to remove objects from orbit. Instead of blasting pieces of debris (which would only create more flying junk), the group’s plan calls for using a medium-powered ground-based laser combined with a terrestrial telescope to illuminate the objects, which will slow them down and cause them to reenter the atmosphere and burn up.

The Technology Review blog noted that this process isn’t as outlandish as it seems. In fact, in the 1990’s, the Air Force studied the idea, but never acted on it. The Air Force had intended to use a powerful laser, but such a system could also be used as a weapon, which would have raised concerns from other spacefaring nations, the blog said.

The NASA/Cornell system would rely on the photons of the laser itself to decelerate an object. By illuminating a targeted piece of debris for a couple of hours per day, the researchers estimated that a 5-kilowatt laser would be sufficient for the job and that such a device could zap up to 10 objects a day.