FISHER-X: A Bioinspired Robotic Alternative for The Exploration of the Oceanic Environment on a Jupiter's Moon

A planetary science mission seeking to explore an ocean world has challenging requirements and demands for a novel design. This work presents the conceptual design of a small probe able to explore the alleged pristine subsurface aquatic environments of Europa, the natural satellite of Jupiter. Assuming a future mission scenario, after the success of Europa Clipper and JUICE, the probe would travel to Europa inside an ice-perforation robot onboard a spacecraft that once on the icy moon orbit would send both probes to the surface inside a lander. On the surface the cryobot would travel drilling through the crust, transporting the underwater probe to the ice-water interface. Once a water layer is reached, being this a brine pocket or the ocean itself, the underwater probe is deployed to map the surroundings while evaluating the habitability of the aqueous environment and search for biosignatures in the water column and the ice. The deployment of a small underwater probe is justified in that it extends the analysis range of its mothership, exploring areas not affected by the perforation of the ice, and through a bioinspired propulsion-stabilisation system that prioritises the non-disturbance of the environment when it is carefully analysed. The basic structure of the concept, named FISHER-X, was modelled using 3D design software. The fin-based propulsion of this concept, which mimics the fully undulatory motion of the biological model, was for the first time described and modelled, based on the biological model visual records. The preliminary mission requirements, and proposed technology for FISHER-X are reviewed, considering the extreme conditions expected in the aqueous layer under the Europa ice shell and the current developments regarding ocean-access mission technologies. Materials and technology associated with navigation, power and payload sensors are proposed based on the most advanced probes to date tested, collecting data and samples, from polar subglacial environments, submerged caves and the bottom of the Earth ocean, among other ocean world analogues.