Dynamics of a tethered satellite formation for space exploration modeled via ANCF

This paper studies the dynamics of a spinning three-body tethered satellite formation by a flexible multibody dynamics method. The tethered system is specially designed to constitute a Space Infrared Interferometric Telescope for a space exploration mission. Two sub-satellites are deployed from the main-satellite by using long flexible tethers and moving along trajectories of Archimedes spirals. Both of the large displacement and large deformation of the variable-length tethers are described by utilizing the Absolute Nodal Coordinate Formulation method in a framework of Arbitrary Lagrange-Euler (ANCF-ALE) description. The Natural Coordinate Formulation (NCF) method is used for describing the overall rigid motions of the three satellites. Considering the mass flow of tether element, the dynamic equations of tether element are derived by using the D'Alembert's principle. The governing dynamic equations of the system are obtained with a method of Lagrange multipliers. The tether deployment is achieved by regulating deployed velocity and applied jet forces. Numerical case studies are presented for investigating the parametric influences on the deployment dynamics of the tethered system by comparisons.