Electric sail static structural analysis with finite element approach

The propulsive characteristics of an Electric Solar Wind Sail are usually evaluated using a simplified model in which all the sail tethers are coplanar and form a sort of rigid disk. However, the three-dimensional arrangement of the tethers is fundamental information in the study of the spacecraft performance, and must be accounted for in refined mission analyses. In this paper, a Finite Element approach is chosen to estimate the deflected shape of the tethers, thus allowing important information on the structural response of the sail to be obtained. A parametric code is developed to perform a static analysis of an Electric Solar Wind Sail, whose requirements are given in terms of payload mass and spacecraft characteristic acceleration. In particular, the tether structural response is investigated using three different beam models, which are compared in terms of accuracy and computational efficiency. The analysis is specialized to the noteworthy case of a Sun-facing sail that is placed at a distance of one astronomical unit from the Sun. The numerical results, which concern a set of possible sail configurations, are compared with those taken from analytical models.