In an increasingly competitive satellite market, electric satellites are expected to garner a growing share of the market, between 25% and 50% by 2020, as estimated by industry players. Among the different electric propulsion systems, Hall effect Thrusters are developed in France by SNECMA, the industrial partner of the chair. SNECMA has pioneered electric propulsion systems in Europe and has successfully sold plasma propulsion systems based on Hall effect thrusters for orbital propulsion and control of space probes and satellites. A key issue for SNECMA in coming years is to develop low power (300-500W) Hall effect thrusters to address the exploding market of small satellites in low-Earth orbits (i.e. at altitudes from 500 to 2000 km). Hall effect thrusters have been extensively studied since their invention in the 1960s. However, the physics of magnetized plasmas typical of these thrusters is complex; several plasma processes that have direct relevance to the thruster performance and lifetime are still poorly understood. Today, the design and development of Hall effect Thrusters is still semi empirical with long and expensive life tests. The final objective of the POSEIDON Chair is to develop a new experimental/numerical methodology to reduce the number of experimental tests in the development of future Hall effect thrusters. The chair is structured around four scientific axes, plus one axis on the project management and coordination, and one axis on know-how transmission, expertise, training and teaching. In the scientific axes, we propose to develop innovative fundamental and applied research activities, for both experimental and numerical studies, to better understand crucial plasma processes occurring in Hall effect thrusters: electron transport, interaction with walls and erosion, and address the question of alternative propellants. The main goals of this project are to better understand plasmas in the real architectures of Hall effect thrusters, to develop 3D numerical tools for the simulation of such problems and to make them available to the industry, to use these tools to improve the efficiency of existing products and in this manner to provide the foundation for breakthroughs in the designs of new electric thrusters. The chair is hosted by LPP, a joint research laboratory between CNRS, Ecole Polytechnique, Université Pierre et Marie Curie, Université Paris Sud and Observatoire de Paris. LPP contributes through its internationally recognized expertise in plasma physics. The Chair holder Anne Bourdon is a CNRS research director (DR2). In 2014, she joined the LPP laboratory to contribute to the development of numerical simulations. The Chair will inject the needed expertise and energy in a fundamental and applied research domain of strategic interest, both scientifically and economically. As a joint project involving academics and industry, the POSEIDON Chair will reinforce the collaboration between LPP and SNECMA. For LPP, it will allow to anchor a strategic axis of research in a long-term partnership with an industrial leader in the field. For SNECMA, the POSEIDON project will improve its reactivity, expand its market position and confirm its leadership position in the very competitive market of electric propulsion. Regarding the international recognition of the partners, this Chair will participate to the visibility of the French expertise in the field of electric propulsion worldwide. Finally, this chair will allow the training of experts on electric propulsion that could be recruited by research laboratories or the industrial partner in order to sustain its investment in a long-term strategy.