Aerospace engineering

The course aims to provide a preliminary understanding of mission profiles for space exploration and the instrumentation used as payload. The program is structured as follows: ----- Introduction ----- • Types of missions for solar system exploration: flyby spacecraft, orbiter, lander, rover, atmospheric probes, aerostatic balloons, quadcopters, penetrators, and formations • Reference systems (ICRF and body fixed) and time systems (UTC and TDB) • Keplerian orbits and flybys for space exploration • Local Mean Solar Time and Local True Solar Time ----- Orbital Configuration ----- • Orbital perturbations: Gravitational and non-conservative forces • Methods to determine orbital evolution: special perturbation (Cowell and Encke) and general perturbation methods (variation of constants) • Heliosynchronous and (quasi-)frozen orbits for space exploration • Elliptical Lunar Frozen Orbits for Moon's exploration ----- Attitude ----- • Definition of attitude matrix • Euler axis and angle • Nadir and off-nadir pointing ----- Observation and Exploration Geometry ----- • Celestial sphere geometry • Taxonomy and theorems of spherical triangles • Relative geometry between spacecraft and central body • Definition of planetary surface pointing • Field of view and area access rates • Surface coverage determination • Error sources for pointing and mapping ----- Instrumentation for Space Exploration ----- • Objectives of space exploration missions • Science themes for space exploration • Surface composition, geology, and geomorphology • Geodesy, geophysics, and internal structure • Atmospheric science and magnetosphere • Classification of sensors for space exploration • Overview and operational parameters of direct-sensing instruments • Detectors • Plasma instruments • Mass spectrometers • Magnetometers • Fundamental principles and properties of electromagnetic waves • Overview and operational parameters of remote sensing instruments Passive instruments: • Optical cameras • Polarimeters • Photometers • Visible and near-infrared spectrometers • Radiometers • X-ray and Gamma-ray spectrometers, and neutron detectors Active instruments: • Synthetic Aperture Radar (SAR) • Altimeters • Sounders • Optical cameras and spectrometers • CCD and optical configuration • Pinhole camera model • Reflectance and spectral signature • Multi- and hyper-spectral cubes • Framing camera and scanning/pushbroom systems • Spatial, temporal, radiometric, and spectral resolution • Global and local topography models • Altimeters Radar altimeters • Microwave frequency bands • Radar equation and backscatter • Pinhole camera model • Range measurement and slant range resolution • Footprint size Laser altimeters • Transmitter and receiver • Time-of-flight measurement • Laser pulse divergence • Footprint size • Geometry of the altimetric measurement • Corrections and error budget ----- Preliminary Design of a Space Exploration Mission ----- To access the simplified mode of the final exam, which involves a written test, students may complete an individual report that includes the preliminary study of a space exploration mission. The exercise text will provide mission requirements and objectives related to exploring the target body. • Orbital phases: 1. Transfer phase; 2. Capture phase; 3. Primary scientific phase • Selection of a stable orbit aligned with mission requirements. • Selection of space exploration systems that fulfill scientific objectives. • Surface coverage of areas of interest providing performance in terms of spatial and temporal resolution.

The prerequisites of the course are all the compulsory courses of the Degree in Aerospace Engineering.

Larson, Wiley J., and James Richard Wertz. Space mission analysis and design. No. DOE/NE/32145-T1. Torrance, CA (United States); Microcosm, Inc., 1992. Wertz, J.R., 2001. Mission geometry; orbit and constellation design and management. Space Technology Library. Battin, R.H., 1999. An Introduction to the Mathematics and Methods of Astrodynamics, revised edition. American Institute of Aeronautics and Astronautics. Hintz, G.R., 2015. Orbital mechanics and astrodynamics. Techniques and Tools for Space Missions. Springer.

As a result of the emergency caused by the Covid 19 pandemic, the course is based on the blended learning. The lectures will consist in face-to-face classroom practices with a reduced number of students, and will be simultaneously presented online through video conferencing (e.g., Zoom, GoogleMeet). To attend the lectures in the classroom, the students will need to follow Sapienza's guidelines. The educational material will be recorded and shared with the students through Google Classroom.

In-person attendance is recommended. Lecture recordings are provided through Google classroom.

1) First written exam (duration: 2 hours) The first part consists of 5 multiple-choice questions (3 points each) and one applied exercise (15 points) based on scenarios from existing or planned space missions. The maximum score is 30/30. Each multiple-choice question requires a brief justification of the reasoning behind the selected answer; choosing the correct option alone is not sufficient to receive full credit. The purpose of this exam is to assess the student’s ability to independently apply course knowledge to problem-solving. Students are allowed to consult official course materials (slides), but personal notes, exercises, and their solutions are not permitted. 2) Second written exam (duration: 30 minutes) The second part, held on the same day as the first exam after a break of 1–2 hours, focuses on theoretical knowledge. It consists of 3 open-ended questions, each worth up to 10 points, requiring concise answers supported by a brief demonstration or explanation. This part is also graded on a 30-point scale. Final grade: The final score is determined by the arithmetic mean of the two written exam scores, rounded to the nearest whole number. The evaluation criteria are: minimum knowledge (scoring between 18 and 20); average knowledge (21-23); ability to apply knowledge sufficiently (24-25); good ability to apply knowledge (27-28); ability to apply knowledge in an excellent way and critical approach (29-30 with honors)

The course is held in person in the classroom. Lectures are recorded and made available online via videoconferencing platforms (e.g., Zoom). All teaching materials, including lecture recordings, will be uploaded and accessible to students through Google Classroom.