Scientists from Stanford and NASA have designed a new gecko-inspired robotic gripper that can grab and dispose of space debris that pose a hazard to satellites, spacecraft and astronauts aboard those vehicles.
About 500,000 pieces of human-made debris are whizzing around space, orbiting our planet at speeds up to 28,000 kilometers per hour. This debris poses a threat to satellites, space vehicles and astronauts aboard those vehicles. What makes tidying up especially challenging is that the debris exists in space. Suction cups don’t work in a vacuum.
Traditional sticky substances, like tape, can not withstand the extreme temperature swings. Magnets only work on objects that are magnetic.
Most proposed solutions, including debris harpoons, either require or cause forceful interaction with the debris, which could push those objects in unintended, unpredictable directions.
To tackle the mess, researchers from Stanford University and NASA’s Jet Propulsion Laboratory (JPL) have designed a new kind of robotic gripper to grab and dispose of the debris. “What we’ve developed is a gripper that uses gecko-inspired adhesives,” said Mark Cutkosky, professor at Stanford University in the US.
The group tested their gripper, and smaller versions, in their lab and in multiple zero gravity experimental spaces, including the International Space Station (ISS). “There are many missions that would benefit from this, like rendezvous and docking and orbital debris mitigation,” said Aaron Parness from JPL.
“We could also eventually develop a climbing robot assistant that could crawl around on the spacecraft, doing repairs, filming and checking for defects,” said Parness. The adhesives have previously been used in climbing robots and even a system that allowed humans to climb up certain surfaces.
They were inspired by geckos, which can climb walls because their feet have microscopic flaps that, when in full contact with a surface, create a Van der Waals force between the feet and the surface. These are weak intermolecular forces that result from subtle differences in the positions of electrons on the outsides of molecules.
The gripper has a grid of adhesive squares on the front and arms with thin adhesive strips that can fold out and move toward the middle of the robot from either side, as though it is offering a hug. The grid can stick to flat objects, like a solar panel, and the arms can grab curved objects, like a rocket body. Researchers hope that they can manufacture larger quantities of the adhesive at a lower cost. He imagines that someday gecko-inspired adhesive could be as common as Velcro.