Kinetic Simulation of Spacecraft–Environment Interaction

A review is presented of the physical processes and numerical approaches used to simulate the interaction of spacecraft with space environment. Following a brief survey of previous work in the field, a discussion is presented of the physics of spacecraft charging caused by plasma and radiation encountered in space environment. Relevant numerical approaches are also presented, with a particular emphasis on the particle-in-cell (PIC) approach in which space is discretized with an unstructured tetrahedral mesh, and Poisson's equation is solved with the method of finite elements. Example simulations are presented showing the interaction of a spherical object with flowing plasma, and comparisons are made with previously published results. A powerful method based on test particle backtracking and Liouville's theorem is presented to calculate particle velocity distribution functions and moments with reduced statistical errors. Results obtained with this approach are compared with similar results obtained directly from the PIC approach.