Study and analysis of energy-optimal pointing manoeuvres for an astrometric space telescope with exoplanet detection purposes

The search for extrasolar planets is a fundamental resource for expanding our understanding of the Universe and investigating the likelihood that other worlds might harbour life. Among the several approaches employed for this purpose, the astrometric method offers significant advantages, as it provides an accurate estimate of the mass of the planet under consideration, which is not required to be necessarily aligned with the line of sight of the observer as for the transit or radial velocity techniques. This thesis aims at analysing and simulating the pointing manoeuvres required by a future spacecraft carrying an optical instrument such as RAFTER (Ring Astrometric Field Telescope for Exoplanets and Relativity) to properly fulfil the objectives of an exoplanet astrometric search mission whilst minimizing the associated energy cost. RAFTER is an annular field telescope conceived and proposed with the goal of achieving consistent optical response over a wide field of view, which exhibits a compact and scalable design and enforces circular symmetry for each optical element. Following an outline of the scientific case under scrutiny and a thorough dissertation of the theoretical aspects covered, the present work introduces the potential configurations selected for the satellite and an overview of the mission it shall undertake, with a particular focus on the field-of-view shift manoeuvres evaluated in this study. Subsequently, the mathematical model addressing the dynamics of the system and the optimal control problem implemented to simulate the manoeuvres at stake are detailed. Finally, the results obtained are provided and discussed.