Modular Dynamic Modeling and Simulation of a Cable-Actuated Flexible Solar Sail

This paper presents a modular dynamic modeling approach to simulate a solar sail embedded with actuated cables within its flexible structure. The cables are routed along the length of the flexible booms that hold the solar sail membrane in such a manner that tensioning the cables results in a bending deformation of the booms. This provides a mechanism where actuation of the cables can be used to create an imbalance in solar radiation pressure (SRP) on the sail and thus, impart SRP torques that can be used for momentum management of the solar sail. The modular aspect of the modeling and simulation approach presented in this paper allows for various designs of this cable-actuated solar sail concept to be assessed without having to re-derive the system dynamics. The dynamic model is developed by first deriving equations of motion of the various components of the solar sail, including a rigid hub, four flexible booms (modeled as Euler-Bernoulli beams), and a flat sail membrane, then modularly constraining the components together without the need for Lagrange multipliers. Simulation results are included that demonstrate how SRP torques can be induced by tensioning the solar sail's cables.