Spacecraft must exist in an environment with charged particles and electric and magnetic fields. As the charged particles strike the spacecraft, such as a satellite, the spacecraft will develop a net positive charge, which will then influence the particle trajectories near the satellite, and cause an even more complicated charging pattern. If the potential difference between two areas of the spacecraft becomes too large then shorting can occur, which can damage the spacecraft, especially the vulnerable electronics. Understanding the charging is thus important to design satellites and spacecraft that can withstand the harsh space environment.
As part of NASA funded research, Tech-X applied VSim to simulate the spacecraft charging in the case when the solar wind storm enters in the regions where the satellite operates. VSim simulations measured the net surface charges buildup on the spacecraft structures due to the solar wind and space plasma. In this simulation, the satellite's inner body is biased at a higher potential compared to the surrounding space environment. Figure 1 shows VSim electrostatic potential results on the satellite surfaces, which are due to net positive charges buildup on the satellite structures. VSIM simulation helps to determine the localized regions where the voltages peak occurs.
VSim includes sophisticated charged particle dynamics, including the self-consistent space charge effects that occur when many particles are included. By being able to study the particle motion, the simulations can predict the net charges buildup on the satellite structures under various space environments. The surface charges collected are self-consistently applied to the calculation of electric potential and localized electric field strengths. These results are useful to analyze the vulnerability of satellite structures under harsh space environment and issues such as surface breakdown in spacecraft structures.