Snake-like robots will travel to outer space

A team at NASA's Jet Propulsion Laboratory is working tirelessly to develop a snake-like robot that can traverse extreme terrain and reach areas that are difficult for humans to reach. This robot can explore uncharted territory without the need for real-time human control.

Initially, scientists wanted to descend through narrow vents in the icy crust of Saturn's moon Enceladus to search for signs of life in the ocean hidden beneath the icy shell of Saturn's moon Enceladus. The geysers that entered space have produced highly adaptable robots designed for such a challenging destination, so this self-propelled autonomous robot was born.

The robot, called EELS (for Exobiology Extant Life Surveyor), can pick a safe route through a variety of terrains on Earth, the Moon and beyond, including undulating sand and ice, cliff walls, craters too steep for rovers, underground lava tubes and the labyrinthine spaces inside glaciers.

Due to the communication lag time between Earth and deep space, EELS will need to autonomously sense its environment, calculate risks, act and collect data using yet-to-be-determined scientific instruments. When problems arise, the robot will need to resolve them on its own without human assistance.

The robot began research in 2019 and is expected to be released online in the fall of 2024. Its applicability is currently being extensively tested in various environments to ensure that it can operate autonomously without control in extreme environments and transmit the collected data to scientific researchers.

The current version of the robot weighs 100 kilograms and is about four meters long. It is made up of 10 identical rotating parts and uses threads for propulsion, traction and gripping. Currently, 3D printed plastic threads are tested on looser terrain, while narrower and sharper black metal threads are used for testing on ice.

The robot's "snake head" uses 3D cameras and lidar that can send real-time video to the operator. Four pairs of stereo cameras and lidar can create a 3D map of its surroundings, and using data from these sensors , the navigation algorithm can find the safest way forward; the robot's body is also equipped with payloads and sensors, allowing scientists to capture underground pressure, conductivity and temperature. It is currently necessary to create a "gait" library for the robot as soon as possible, so that the robot can move in response to terrain challenges, from sideways to self-curling, which the team calls the "banana" action.

The robot's action mechanism is an actuator group composed of 48 small motors, which allows it to flexibly adopt a variety of configurations, but increases the difficulty of the hardware and software teams. These actuators can be seen as 48 "steering wheels" with many torque sensors built in, which work like skin, allowing the robot to feel the force exerted on the terrain, which helps the robot move up and down in narrow passages with uneven surfaces and configure itself to propel itself on the opposite wall like a rock climber.

"Imagine a self-driving car, but there are no stop signs, no traffic lights, or even any roads," said project leader Carolyn Miller, as she introduced the robot. "The robot has to figure out what the road is and then try to follow it, and it needs to descend 100 feet without falling off. So far, our focus has been on autonomous capabilities and mobility, but eventually we will look at what scientific instruments can be integrated with EELS."

The advantage of the EELS snake robot is that it has the ability to go where other robots cannot go. Although some robots perform better in certain environments, EELS aims to be a more versatile robot that can perform on any terrain. When you are going to a place where you don’t know what you will find, you will think of sending a versatile, risk-aware robot that can make its own decisions to deal with uncertainty.

It is reported that once the EELS snake robot is ready, it will take about 12 years for the spacecraft to transport EELS to Saturn's moon. Researchers hope that once the robot finds a vent to enter Saturn's moon, it will only take a few days to reach the ocean ice shell. If all goes well, this snake robot can take the exploration of ocean worlds to a new level. NASA said when talking about the robot that the EELS system is a mobile instrument platform designed to explore internal terrain structure, assess habitability and ultimately search for evidence of life. It is designed to adapt to traversing ocean world-inspired terrain, fluidized media, closed maze environments and liquids.