The student will acquire the skills needed to: • understand and deal with different kinds of space missions and the systems devoted to carry out the mission, by using the methods typical of system engineering; • design and analyse space missions and systems, using methodologies, tools, processes and standards of aerospace engineering; • deal with issues such as reliability, safety and cost of complex systems and integrate them in the design; • use the most popular simulation software in support to the design. In order to enhance the capability of autonomous judgment and the communications skill, the students will be encouraged to: • Carry out design cases on specific assignments; • Estimate the order of magnitude of numerical values, that can be reasonably expected in some reference case-studies; • Write technical reports according to standards commonly used in the aerospace engineering field (ESA and/or NASA); • Present his/her work to professors and colleagues within a simulated MDR and/or PRR; • Learn the international terminology, in particular the English terminology. Knowledge of the main space maneuvers and evaluation of their propulsive requirements and extended knowledge of the most important electric propulsion system and their performance are required.

It is necessary that the students who will take this course have good skills in the fields of mathematics and physics. A good general knowledge of the existing types of space systems, astrodynamics, propulsion and electronics is required.

SPACE MISSIONS AND SYSTEMS DESIGN Lessons: Study of past and present space missions and overview on future missions. Space mission elements and their integration: mission concept and mission architecture. The elements: mission object, payload, bus, launch system, orbits, ground systems, operations, communications. The mission segments. How to define a payload: analysis of the mission object and choice of the payload. Guidelines for payload sizing. Review of onboard subsystems and their functions. Guidelines for subsystems sizing. Tools of systems engineering: methods for trade-off and decision making. Elements and tools of Project Management. Risk and Cost analyses. Space mission design (project work): Design phases: from conceptual study to the preliminary requirements review (PRR). Mission objectives definition. Study of the mission subject. Methods for analysis and definition of mission requirements and their allocation. Functional analysis to define mission architecture and functional requirements. Methods to trade-off alternative architectures. Methodologies, techniques and tools for primary system development. Mission geometry definition. Constraints and requirements review. Designing and sizing the payload, the space support systems and the ground system. Project budgets development. Design of the verification campaign for qualification and acceptance. Dependability and safety analysis. Cost analysis. Speeches given by external experts and representatives from aerospace companies and agencies. SPACE PROPULSION Principles of space propulsion. Thrust and specific impulse. Tsiolkowski's equation. Velocity losses. Comparison of chemical and electric propulsion. Optimal specific impulse. Single-stage and multi-stage rocket performance. Escape and capture maneuvers, interplanetary transfers, flyby. Electromagnetism, ionization and definition of plasma. Collisions between particles: types of collision, cross sections. Scalar electric conductivity and Hall parameter; particle motion in varying electromagnetic fields. Electrothermal propulsion; typical losses and propellant. Resistojets: characteristics and performance. Arcjets: characteristics and performance. Electrostatic propulsion: ionization and ideal efficiency. Electrostatic acceleration: Child's law and two-dimensional effects, acceleration-deceleration concept. Neutralization. Characteristics and performance of electrostatic thrusters. FEEP and colloidal thrusters. Hall's effect thrusters: geometry, operations, and performance. Electromagnetic propulsion: magnetoplasmadynamics equations; self-field MPD thrusters: pumping e blowing. Performance of self-field and applied-field MPD thrusters. Vasimr. Unsteady electromagnetic propulsion; PPT characteristics and performance. Power generators. Nuclear propulsion, advanced propulsion concepts, solar sails.

SPACE MISSIONS AND SYSTEMS DESIGN An assignment will be proposed to develop a space mission design. The students, split into separate teams, will deal with the design of a space mission in response to specific stakeholders needs. The themes of the assignment are expression of most recent trends in the aerospace research field. The assignment is configured as a project work during which methods, techniques and tools presented during the lectures are applied and tested to a real case, following the hands-on-practice approach. The project work is the most important part of the course, and it takes at least half course time duration. Several tools will be used during the development of the design, depending upon the design phase and specific needs. In addition to the most popular software for analysis (Matlab Simulink, Excel), specific software suites will be used for the purpose (SolidWorks, GMAT/ASTOS/STK). During the project work additional reference material and tolls can be given depending upon the needs. The project work is carried out for the most part in the information laboratory under the supervision of professor and her research team. The project work shall be reported in the final report and presented through presentations. SPACE PROPULSION In addition to theoretical lessons, numerical exercises will be performed, for the determination of the optimal specific impulse for a given space mission and the performance analysis of electric thrusters.

SPACE MISSIONS AND SYSTEMS DESIGN Specific reference material has been prepared by professor and is made available to the students on the web (lecture notes are provided in English). The following reference textbooks are also suggested (some of them are available on the web, others can be borrowed from the library): Space Mission Analysis and Design (SMAD), 3rd Edition, W.J. Larson and J.R. Wertz, Space Technology Library, Vol. 8 Space Mission Engineering: The New SMAD, J.R. Wertz, D.F. Everett, J.J. Puschell, Space Technology Library, Vol. 28 Elements of Spacecraft Design, C.D. Brown, AIAA Education Series Mission Geometry; Orbit and Constellation Design and Management, J.R. Wertz et alii, Space Technology Library, Vol. 13 Human Spaceflight; Mission analysis and Design, W.J. Larson, Space Technology Series, McGraw Hill ECSS standards (http://www.ecss.nl/) NASA System Engineering Handbook, NASA/SP-2007-6105, Rev1. SPACE PROPULSION R. G. Jahn, Physics of Electric Propulsion, first edition, McGraw-Hill, New York, NY, 1968. L. Casalino Handouts available on the course site.

Exam: Compulsory oral exam;

SPACE MISSIONS AND SYSTEMS DESIGN At the end of the course, an examination takes place to test the knowledge of the student. Each student shall attend the examination on both theory and project work. Each student shall present and defend his/her project work during the oral exam. It is suggested that the student brings his/her own report copy. The report shall be submitted in advance on the webpage of the course for examination by the professor (due date will be communicated during the term). The final mark is given on the basis of the overall work done by the student during the project work (verified in particular during PDR/CDR presentations) and the result achieved in the final oral exam. SPACE PROPULSION Oral examination. The exam consists in two or three questions about the course program, with discussion and execution of simple calculations to assess the acquisition of the required knowledge.

In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.