Satellite surface charging in LEO with ProPIC

ProPIC is a fully kinetic particle-in-cell (PIC) solver developed for space electric propulsion. This work has extended its capabilities to simulate satellite surface charging and wake generation in low Earth orbit (LEO). A novel scaling approach has been implemented, decreasing computational cost by more than one order of magnitude. The methodology and scaling approach have been verified against the revised orbital-motion-limited theory. The surface charging and wake generation in LEO have been examined for a satellite that is more complex and larger than what is typically handled with a fully kinetic PIC approach in LEO, particularly due to the presence of large solar panels. Notably, the simulated wake can be used to identify the optimal position for the plasma diagnostic sensor that minimizes interference with the wake. Moreover, despite not being a failure risk, the attitude greatly influences the surface charging of a satellite with large solar arrays installed parallel to the satellite speed vector. The study suggests that, for high positive pitch angles ($>$45${}^{\circ }$), the surface charging of the solar panels can increase by as much as 75% compared to low negative pitching cases. Additionally, the study highlights that the pitch angle and satellite envelope along the motion direction significantly influence the potential gradients on the solar panels.