Simulation study of the plasma brake effect
  The plasma brake is a thin negatively biased tether which has been proposed as an efficient concept for deorbiting satellites and debris objects from low Earth orbit. We simulate the interaction with the ionospheric plasma ram flow with the plasma brake tether by a high performance electrostatic particle in cell code to evaluate the thrust. The tether is assumed to be perpendicular to the flow. We perform runs for different tether voltage, magnetic field orientation and plasma ion mass. We show that a simple analytical thrust formula reproduces most of the simulation results well. The interaction with the tether and the plasma flow is laminar (i.e., smooth and not turbulent) when the magnetic field is perpendicular to the tether and the flow. If the magnetic field is parallel to the tether, the behaviour is unstable and thrust is reduced by a modest factor. The case when the magnetic field is aligned with the flow can also be unstable, but does not result in notable thrust reduction. We also fix an error in an earlier reference. According to the simulations, the predicted thrust of the plasma brake is large enough to make the method promising for low Earth orbit (LEO) satellite deorbiting. As a numerical example we estimate that a 5 km long plasma brake tether weighing 0.055 kg could produce 0.43 mN breaking force which is enough to reduce the orbital altitude of a 260 kg object mass by 100 km during one year. 
Pekka Janhunen
astro-ph.IM physics.plasm-ph