In-Orbit-Service (IOS) has moved from visionary proposal to operational necessity for keeping orbits safe, sustainable and affordable. In fact, repairing, refuelling, upgrading or de-orbiting aging satellites lowers replacement costs and reduces collision risk. The lowering of launch prices has sharpened commercial interest; indeed, market studies foresee a multi-billion-dollar commercial sector expanding at a high growth rate over the coming decade. For these reasons, this thesis work aims to plan and validate impulsive rendezvous manoeuvres through a modular MATLAB tool for IOS that combines an optimization process based on an evolutionary algorithm (EA) with a 3-DOF orbital simulator. The aim of the optimization process is to minimize propellant consumption in terms of the ΔV provided by a classic Lambert’s problem.