关键词: 航天器, 静电场, 表面电位, 介电常数, 静电放电

Abstract:

 The analytic expression of the electrostatic potential near the spacecraft surface is obtained by solving the Poisson equation based on the electrostatic field theory, and the mathematical expression of the electric field intensity near the spacecraft surface is deduced. Using the boundary condition of the electromagnetic field, the dielectric surface potential-permittivity model is established, and the relationship among the dielectric surface potential, surface charge and permittivity is gained. Taking the practical cases for example, the change regulation of the surface charge with surface potential and the distribution of the electrostatic field near the spacecraft surface is discussed, and the effect of the dielectric constant on the surface charge and surface potential is analyzed. The results show that the electrostatic field induced by the dielectric surface charge decreases as the distance incrases when the surface potential of media is constant, and the surface potential of media decreases with the increase of the dielectric permittivity and tends to a stable value under the condition that the dielectric material has equal charge. Therefore, it is possible to select the dielectric materials with smaller permittivity under certain conditions to reduce their surface potential, and to reduce the probability of the electrostatic discharge between different media.

Key words: Spacecraft, Electrostatic field, Surface potential, Permittivity, Electrostatic discharge