Modeling, Estimation, and Prototype Design for the Cable-Actuated Bio-inspired Lightweight Elastic Solar Sail

Abstract

Traditional spacecraft that utilize rocket engines for propulsion have a fundamental drawback in that they require the use of rocket fuel. As a result, there is a need to develop spacecraft with alternative means of propulsion that can extend the effective mission range without relying on heavy, expensive rocket fuel. One of the most promising alternative means of propulsion is the solar sail. These sails utilize the reflection of solar radiation pressure and the corresponding transfer of momentum to achieve propulsion. However, one of the most significant challenges pertaining to solar sail design is the means by which stabilization and attitude control are achieved. To address these challenges, this thesis presents the concept of the Cable-Actuated Bio-inspired Lightweight Elastic Solar Sail (CABLESSail). This novel solar sail concept uses cable-actuated flexible beams to achieve stabilization and attitude control by means of sail shape modulation. Analysis is shown that confirms the feasibility of the CABLESSail model by demonstrating that NASA mission attitude control requirements for both Solar Cruiser and Solar Polar Imager can be achieved through cable actuation. A method to predict the end-effector pose given the cable lengths or cable tension is discussed, with intended application in a control algorithm to control the end-effector pose. A prototype cable-driven continuum manipulator is designed for use as the cable-actuated flexible beam. The cable-driven continuum manipulator is modeled in simulation, and the simulation results of the beam deflection, induced cable torque, and the change in motor position are compared to experimental results.