Area-of-Effect Softbots (AoES) for Asteroid Proximity Operations

This paper will provide an introduction and overview of Area-of-Effect Softbots (AoES), which are currently in development under a Phase 2 NASA Innovative Advanced Concepts (NIAC) project. AoES are designed to operate in proximity to, and on the surface of, small asteroids to support mining and planetary defense missions. Their unique design and capabilities are dependent on the incorporation of soft, compliant, and lightweight materials. AoES have a large area-to-mass ratio which allows them to take advantage of the peculiarities of the dynamical environment around small asteroids. Specifically, AoES will use solar radiation pressure to sail to the surface of the target asteroid after being deployed at a safe altitude from a mothership around the asteroid. This capability and the associated control laws will be demonstrated, removing the need for propulsion systems. Furthermore, the large, flexible surface area allows for robustness with respect to uncertainty about the asteroid surface structure - it can provide flotation to prevent sinking into a very loose, dusty regolith, and also provide anchoring to the surface through natural and electroadhesion forces. The enabling technology that will allow the AoES design loop to close is a new class of soft actuators known as HASEL actuators. These actuators harness an electrohydraulic mechanism, whereby electrostatic forces generate hydraulic pressure to drive shape change in a soft fluid-filled structure. HASELs provide an extremely power- and mass-efficient mechanism for actuating the large flexible surface areas that are the essential components defining AoES. Current system design, requirements, and key tradeoffs will be discussed - with a particular focus on the actuation, mobility, anchoring, materials, and power systems/components. The nominal mission profile and concept of operations for using AoES in an asteroid mining mission will be outlined.