Washington, Dec 20 (IANS): NASA scientists are working on adhesive gripping tools that could tackle objects such as orbital debris or defunct satellites that would otherwise be hard to handle.

“Orbital debris is a serious risk to spacecraft including the International Space Station (ISS). This is definitely a problem we are going to have to deal with. Our system might one day contribute to a solution,” said Aaron Parness, robotics researcher at NASA's Jet Propulsion Laboratory in Pasadena, California.

The gecko gripper project was selected for a test flight through the Flight Opportunities Programme of NASA's Space Technology Mission Directorate.

As a test, researchers used the grippers in brief periods of weightlessness aboard NASA's C-9B parabolic flight aircraft.

The gripping system developed by Parness and colleagues was inspired by geckos, lizards that cling to walls with ease.

Geckos' feet have branching arrays of tiny hairs, the smallest of which are hundreds of times thinner than a human hair.

This system of hairs can conform to a rough surface without a lot of force.

Although researchers cannot make a perfect replica of the gecko foot, they have put "hair" structures on the adhesive pads of the grippers.

The synthetic hairs, also called stalks, are wedge-shaped and have a slanted, mushroom-shaped cap.

When the gripping pad lightly touches part of an object, only the very tips of the hairs make contact with that surface.

"The stickiness of the grippers can be turned on and off, by changing the direction in which you pull the hair," Parness added.

Besides grappling orbital debris, the grippers could help inspect spacecraft or assist small satellites in docking to the ISS, the US space agency said in a statement.