• Air Breathing Electric Propulsion
• Double Stage Hall Effect Thrusters
• Magnetic Coordinates
• Numerical Modeling

An Air Breathing Electric Propulsion (RAM-EP) system is being developed at SITAEL. The RAM-EP concept is to use electric propulsion together with gas collected from the atmosphere to provide thrust for counteracting the S/C altitude decay caused by drag. This technology would enable low altitude missions below 250 km and/or very long lifetime missions above 250 km. The purpose of this master's thesis is to investigate the main features of this relatively new kind of space propulsion and to develop a quasi-onedimensional model for describing the plasma behaviour inside the proposed RAM-EP thruster (a Double Stage Hall Effect Thruster), thus estimating its performances and verifying its capability to withstand LEO and VLEO aerodynamic drag. Since the expected inlet mass flowrates are very low, a Double Stage Hall Effect Thruster is employed in order to enhance ionization by plasma confinement in the ionization stage.
The developed model relies on a one-dimensional approach in magnetic coordinates, in which the dominant plasma gradients are assumed to be orthogonal to the magnetic field lines. All the plasma equations are then integrated over the magnetic surfaces constituting the domain: as a result, differential equations as function of a unique coordinate are obtained.
The model simulations show that the thruster may be able to compensate the drag at discharge voltages higher than 1000 V. The model predicts higher performances when the voltage dedicated to the ionization stage is increased up to one half the total discharge voltage. Due to the lack of an emissive intermediate electrode, the desidered plasma confinement is not achieved in the ionization stage and most of the ionization takes place at the acceleration channel entrance and in the near plume region. In order to validate the proposed RAM-EP system concept, an on-ground test campaign is scheduled at SITAEL's facilities.