A study published in the journal Science Robotics describes a robot developed at Stanford University specifically for cleaning up space debris. The robot can grasp moving objects in sub-gravity conditions. In this study, the researchers developed robotic pincers inspired by the gecko. In experiments at NASA (the US space agency), the researchers showed that the tweezers were able to capture floating objects in microgravity conditions
By Dafna Haim-Langford
When we look up at the sky, it's hard for us to guess that apart from the moon that surrounds us, over five hundred thousand pieces of space debris of various sizes orbit the earth. Scientists from Stanford are developing a tool to collect this waste inspired by the gods.
Space debris consists of decommissioned satellites, remnants of rockets and a lot of man-made garbage that has reached space in the last decades. The movement of debris in space can reach a speed of thousands and tens of thousands of km/h, thus posing a significant risk to all those engaged in space exploration - astronauts, satellites and spaceships. In addition, the collision of pieces of space debris can create an explosion, and this will increase the amount of moving parts in space, a situation that can lead to a catastrophic chain of collisions, known as Kessler Syndrome.
The need to develop a dedicated device for collecting space debris is due to the fact that the tools that exist today are generally not suitable for collecting large parts with a smooth surface. The magnets are not effective in picking up pieces of aluminum or glass (eg, leftover solar cells from satellites), and vacuum suction is not active in the absence of an atmosphere. In addition, various materials such as adhesives are not resistant to the extreme temperatures in space.
In a study published in the journal Science Robotics last June, a robot developed at Stanford University specifically for the purpose of cleaning up space debris is described. The robot can grasp moving objects in sub-gravity conditions. In this study, the researchers developed robotic pincers inspired by the gecko. In experiments at NASA (the US space agency), the researchers showed that the tweezers were able to capture floating objects in microgravity conditions.
The gecko's attachment mechanism, which allows it to walk on smooth surfaces and stick upside down on the ceiling just by touching its fingers, is based on tens of thousands of microscopic hairs that produce attachment to smooth surfaces through weak bonds. Many weak ties create a strong attachment mechanism. The gecko's attachment mechanism has inspired developments in various fields, from gloves for climbing walls to biological adhesives for gluing tissues.
The researchers from Stanford developed the surfaces of the gecko similarly to the gecko's leg, where they based the adhesion ability of the gecko on elements with a thickness of forty micrometers (the hairs of the gecko are approximately two hundred nanometers thick). Movement of these elements in one direction produces linkage, and movement in the other direction causes detachment. The low amount of energy needed to create the movement that leads to attachment is very important for any action in space, as careless movement in space can cause uncontrolled migration of objects in unspecified directions. At this stage, clamps can hold objects weighing up to four hundred kilograms and with a volume of one hundred times the volume of the clamp itself.
Enthusiastic about the results of the experiments so far, the researchers plan to optimize the use of tweezers or connect them to a robot that will one day be able not only to clean space, but also be used to maintain space stations, satellites, telescopes and everything that comes out of the atmosphere in the service of man.