It's no secret that in our decades of space travel, we haven't always cleaned up after ourselves. Space debris--like dead satellites, empty rocket fuel containers, and shrapnel from past collisions like the 2009 Russian satellite crash--is gradually building up in the Earth's orbit. The off-world litter is causing current astronauts real problems, as new missions require careful calculations to keep track of and avoid obstacles. The International Space Station makes adjustments several times a year to avoid disastrous collisions with such space junk. But no one knows how to pull the trash in and get rid of it. Some debris can be hooked if it has a handle, but much of the trash is made of up smooth surfaces that have no access points.

In space, grabbing onto things is hard. A new robot that uses grippers inspired by gecko feet could solve that problem, helping clear up the mess of debris that orbits Earth. The toaster-sized device can grip, hold onto and move around even large, smooth surfaces in microgravity, on both flat and curved objects. To do this, it uses a "dry adhesive" material created by Hao Jiang at Stanford University in California and his colleagues. "This ability to grab onto an object nearly anywhere, instead of needing a specific grapple point that may not even be there, is really advantageous," says Matthew Spenko at the Illinois Institute of Technology in Chicago.

You're so hard to explore. Sometimes you bombard spacecrafts with hurtling rocks and deadly cosmic rays, and other times you're so empty you don't give astronauts a darn thing to hold on to. But while scientists haven't quite figured out how to keep radiation at bay, the scientists at NASA's Jet Propulsion Laboratory--specifically, its Planetary Robotics Laboratory--are building machines that can get a grip on the most difficult surfaces astronauts will find out there. Adhesion-wise, space presents a couple problems. First, robots typically struggle with uneven surfaces, let alone the kind of cliffs and crags you see on Mars.