Subject of this thesis is the design of a space robotic mission to the asteroid 433 Eros. The mission aims to grab a boulder from its surface and transport it inside the Earth's influence sphere. This work was inspired by NASA's Asteroid Redirect Mission (ARM), which was cancelled in 2017 due to lack of funding, and whose purpose was to transfer a boulder from the surface of a Near-Earth asteroid (NEA) to a stable lunar orbit, where it could be further analyzed both by robotic probes and by a future manned mission. The propulsion system used for the theorized mission consists of three autonomous ion thrusters fully adjustable in magnitude and direction of thrust.