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.