Static Structural Analysis of an Electric Sail with Finite Element Approach

To a first order approximation, the propulsive characteristics of an Electric Solar Wind Sail (E-sail) are usually estimated with a simplified model in which all of the E-sail tethers are coplanar and form a sort of rigid disk. However, the tether arrangement in a three-dimensional pattern is a fundamental information in the study of the E-sail trajectory and must be accounted for in a refined mission analysis. In this paper, a Finite Element (FE) approach has been chosen to estimate the deformed shape of the tethers, thus allowing important information on the structural response of the E-sail to be obtained. A parametric code has been developed to perform a static analysis of an E-sail whose requirements are given in terms of payload mass and characteristic acceleration. The tether structural response has been investigated with three different beam models, which have been compared in terms of accuracy and computational efficiency. The results are reported for several E-sail configurations in a Sun-facing attitude and at a reference heliocentric distance of 1 au, and are compared with those taken from analytical models.