Icy celestial bodies such as Europa and Enceladus stand out as prime candidates for potential extraterrestrial life within our solar system due to the presence of liquid water. However, the quest to unveil any hidden inhabitants in these alien oceans is impeded by the formidable ice cover, which can extend to depths of dozens of kilometers. Communication with these moons poses another challenge, with signals taking up to 155 minutes to travel back and forth.
In addressing these obstacles, researchers at NASA’s Jet Propulsion Laboratory (JPL) have developed a groundbreaking solution under the Exobiology Extant Life Surveyor (EELS) project. Their innovation involves the utilization of an AI-driven space snake robot, a concept that has materialized into a tangible reality.
Exploration Strategy: Geysers on Enceladus
Traditionally, thermal drilling has been the go-to method for penetrating the ice sheets on Enceladus and Europa, akin to techniques employed in glacier research on Earth. However, the accumulation of sediment poses a significant challenge for thermal drilling approaches, affecting the energy required to make substantial progress. To circumvent this issue, the EELS team has pivoted towards leveraging existing ice vents, inspired by the discovery of geyser-like jets on Enceladus by the Cassini mission. By deploying a lander near these vents, the robot can navigate the surface, descend into the vent, explore its surroundings, and further delve into the ocean depths.
Innovative Design: All-Terrain Snakes
To navigate the treacherous and uncharted terrains of these icy moons, the EELS team engineered a versatile bio-inspired snake-like robot measuring approximately 4.4 meters in length and 35 centimeters in diameter. Comprising 10 mostly identical segments, this robot incorporates a unique combination of shape actuation and screw actuation mechanisms to propel itself through various environments. The utilization of “skin propulsion” via screw rotation and shape-based movements enables the robot to maneuver effectively, including employing sidewinding gaits for enhanced traction.
Equipped with a comprehensive sensor suite, including stereo cameras, inertial measuring units (IMUs), and LIDAR sensors, the robot boasts a tactile sense with torque force sensors in each segment. This sensory array enables the EELS robot to ascend and descend the vents, anchor itself during eruptions, and even navigate by touch in the absence of visual or LIDAR cues.
Autonomous Operation: Space Snake Brains
Given the substantial communication latency, manual control of the EELS robot was deemed impractical, leading to the implementation of a highly autonomous system. Ground control is limited to issuing overarching directives, akin to Tesla’s self-driving software. The AI framework governing the robot’s actions is structured around a layered architecture comprising estimators and controllers. Estimators process data from internal sensors to determine the robot’s state and environmental mapping, while controllers manage tasks ranging from basic actuator control to high-level task and motion planning.
The EELS robot’s cognitive framework mirrors the human mind, featuring intuitive machine learning-driven movement capabilities alongside a logic-based model enforcing safety protocols and operational constraints. This dual-system approach ensures efficient and secure traversal of alien icy landscapes.
While the EELS robot is not currently slated for any flight missions, its adaptable architecture holds promise for diverse applications, including terrestrial scenarios. By leveraging its capabilities for scientific exploration, search and rescue missions, and environmental monitoring, the EELS technology remains a beacon of inspiration, with Enceladus serving as a compelling muse for future endeavors.