The mad plan to clean up space junk with a laser cannon

If the notion of lasers in space sounds slightly terrifying, you’re not alone. “The problem with it is mostly political,” says Don Kessler, who spent more than 30 years at NASA’s Johnson Space Center. “Everyone is afraid you are going to weaponize space.” Kessler began the field of studying orbital debris and lends his name to “Kessler syndrome,” a scenario in which colliding debris begins a cascade of increasing debris and destruction.

If you can take out a derelict satellite or rocket body, you also have the ability to kill a working satellite. And given how important satellites are to militaries, an attack could prompt a war. But if astronomers are going to put a laser cannon anywhere above Earth, the ISS would be the place to do it. Bolting the proposed laser to the ostensibly neutral space station—which already must make frequent maneuvers to avoid larger, tracked pieces of debris—might be a way to make a scientifically sound idea politically sound as well.