Design of Space Systems

The course is focused on Electric Space Propulsion, as the new leading technology for in-space propulsion both in Near-Earth and Inner-Solar system applications. The goals of the course are that the students acquire a solid understanding of - the benefits and limitations of electric rocket propulsion versus classical chemical rocket propulsion, for different missions, and from microsatellites to large platforms. - the different types of electric thrusters and their main principles of operations - the main plasma physics concepts inherent to these thrusters - the derivation of performance models to support design, testing, and optimization of these technologies - the main technological constraints found in practice

1. IN-SPACE PROPULSION Propulsion figures of merit: thrust, specific impulse, efficiencies. Propulsive requirements in space missions. Rocket equation. Chemical versus electric propulsion Optimum specific impulse Electric propulsion technologies Missions with electric propulsion 2. CHEMICAL PROPULSION IN SPACE Figures of merit in chemical rockets (nozzles): thrust coefficient, characteristic velocity, etcetera. Monopropellant rockets: cold gas and hydrazine-based rockets. Bipropellant rockets: analysis of fuels and oxidizers. Review of thermochemistry. 3. ELECTRIC PROPULSION: PHYSICAL PRINCIPLES Operation principles of Ion and Hall Thrusters. Maxwell and Fluid equations. Quasineutrality, Debye sheaths, and plasma wall interaction. Collisional processes. Dynamics of magnetized populations. Generalized Ohm¿s and Fourier¿s laws. 4. GRIDDED ION THRUSTERS Thruster elements and electrical configuration. Global model of the discharge chamber: current and power balances. Grid model: Child¿s model and optimal perveance Model of expansion of the plasma jet. Performance laws and efficiencies. Physics of the hollow cathode: thermionic emission. Thruster lifetime. 5. HALL EFFECT THRUSTERS Plasma discharge structure and operational parameters. Global model: current and energy balances, efficiencies. Axial and radial fluid models: electron transport, interaction with walls. Technological aspects: chamber erosion, thermal loads, oscillations, magnetic circuit and topology. Alternative configurations.

They combine - lectures with audiovisual support - discussion and solving of exercises and problems - homework assignements - quizzes Tutorials can be both personally or through Aula Global