Study and analysis of pointing manoeuvres for the RAFTER mission

The search for extrasolar planets is fundamental 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 work aims at analysing 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. 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. A mathematical model describing the dynamics of the system and the evaluation of an appropriate optimal control strategy will be presented. At the end, the selection of proper actuators will also be discussed.