Modeling of Plasma Flow Around SMART-1 Spacecraft

SMART-1 is the first European spacecraft that uses electric propulsion as the main propulsion system. The thruster characteristics and plasma measurements performed during SMART-1 mission lay a good foundation for understanding spacecraft/plasma interactions. This paper discusses the applications and modifications of spacecraft plasma interaction system software, which originally was developed to simulate an interaction of the space plasma with the spacecraft-surface materials and to compute a plasma-induced charging. The particle-in-cell and Monte Carlo collision (PIC-MCC) method and a simplified and fast approach that tracks only slow ion motion are implemented to model the plasma flow around the spacecraft with electric propulsion. The simplified approach consists of a consecutive application of a direct simulation MC (DSMC)-based software for neutral flow, axisymmetric PIC-MCC for plume flow, and three-dimensional (3-D) PIC software for plasma flow around the spacecraft. Three-dimensional computations are performed to analyze the effects of single- and double-charged Xenon ions, constant and spatially variable electron temperature, an application of quasi-neutral assumption or Poisson solver, and low Earth orbit environment on plasma flow around SMART-1. It was shown that a spatially variable electron temperature has the most significant effect on the plasma-flow properties