A novel concept for Titan robotic exploration based on soft morphing aerial robots

This work introduces a novel approach for Titan exploration based on soft morphing aerial robots leveraging the use of flexible adaptive materials. The controlled deformation of the multirotor arms, actuated by a combination of a pneumatic system and a tendon mechanism, provides the explorer robot with the ability to perform full-body perching and land on rocky, irregular, or uneven terrains, thus unlocking new exploration horizons. In addition, after landing, they can be used for efficient sampling as tendon-driven continuum manipulators, with the pneumatic system drawing in the samples. The proposed arms enable the drone to cover long distances in Titan's atmosphere efficiently, by directing rotor thrust without rotating the body, reducing the aerodynamic drag. Given that the exploration concept is envisioned as a rotorcraft planetary lander, the robot's folding features enable over a 30$\%$ reduction in the hypersonic aeroshell's diameter. Building on this folding capability, the arms can morph partially in flight to navigate tight spaces. As for propulsion, the rotor design, justified through CFD simulations, utilizes a ducted fan configuration tailored for Titan's high Reynolds numbers. The rotors are integrated within the robot's deformable materials, facilitating smooth interactions with the environment. The research spotlights exploration simulations in the Gazebo environment, focusing on the Sotra-Patera cryovolcano region, a location with potential to clarify Titan's unique methane cycle and its Earth-like features. This work addresses one of the primary challenges of the concept by testing the behavior of small-scale deformable arms under conditions mimicking those of Titan. Groundbreaking experiments with liquid nitrogen at cryogenic temperatures were conducted on various materials, with Teflon (PTFE) at low infill rates (15-30%) emerging as a promising option.Comment: Presented at International Astronautical Congress 2023 (Baku, Azerbaiyan

Thermally-Resilient Soft Gripper for Space Debris Removal

Space debris poses a significant and growing threat to orbital operations, demanding urgent solutions. Soft manipulators, with their adaptability to various shapes and sizes, present a promising approach to mitigate this concern and facilitate orbital maintenance tasks. Challenges such as radiation, vacuum, and microgravity are significant, but the predominant issue is ensuring these devices operate effectively in the extreme temperature swings from -180{\deg}C to over 200{\deg}C. The majority of soft materials become brittle and hard due to crystallization at cryogenic temperatures or undergo drastic shifts in their elasticity near their melting points. This work pioneers experiments using liquid nitrogen to simulate cryogenic conditions and heat guns for elevated temperatures. It derives insights into the behavior of these materials, leading to the design of a soft gripper tailored for space debris removal in LEO orbits. The multi-layered design leverages the properties of thermoplastic polyurethane at low infill rates for lightweight inherent flexibility, silicone rubber ensuring structural integrity, PTFE (Teflon) for unparalleled thermal stability, and aerogel for insulation. The nylon-crafted tendon-driven mechanism incorporated uses molybdenum disulfide grease as a lubrication layer for cryogenic temperatures. The insights from this experiments and the modeling of the temperature-driven property alterations are pivotal for the advancement of soft manipulators tailored for on-orbit operations.Comment: Submitted to ICRA 202