  This perspective paper deals with an overview of particle-in-cell / Monte
Carlo collision models applied to different plasma-propulsion configurations
and scenarios, from electrostatic (E x B and pulsed arc) devices to
electromagnetic (RF inductive, helicon, electron cyclotron resonance)
thrusters, with an emphasis on plasma plumes and their interaction with the
satellite. The most important elements related to the modeling of plasma-wall
interaction are also presented. Finally, the paper reports new progress in the
particle-in-cell computational methodology, in particular regarding
accelerating computational techniques for multi-dimensional simulations and
plasma chemistry Monte Carlo modules for molecular and alternative propellant
