Trying to Clean a Junkyard That's Out of This World

Scientists are stumped over how to clear the heavens of junk left from five decades of space travel and satellite launches. Although there has been some research on using lasers to change the orbit of small debris and on employing large foam balls that would encase and slow down speeding junk (forcing pieces to drop into the atmosphere at a faster rate), these methods are not yet technically feasible. Says Gene Stansbery, an orbital debris scientist at NASA Johnson Space Center: You can't go up and knock down or blow up a piece of debris because that just creates more particles. Scientists have focused their efforts instead on designing spacecraft that leave behind less waste, though that doesn't help clear the existing junk. To a limited degree, the problem will sort itself out. Debris in orbits below 600 km will drift down toward Earth in a few years, and most pieces won't survive the heat of friction with the atmosphere upon reentry. Yet waste orbiting at higher altitudes isn't expected to return for decades, even centuries. Meanwhile, every time there's a launch, more debris is added to the inventory, says Perry Nouis, a spokesman for the Colorado-based U.S. Space Command, which tracks orbital debris. Don't expect clear skies anytime soon. Illustration for TIME by Daryll Collins