The Ion Beam Shepherd (IBS) is a concept  in which the orbit and/or attitude of a spacecraft or a generic orbiting body is modified by having a beam of quasi-neutral plasma impinging against its surface to create a force and/or a torque on the target. Ion and plasma thrusters commonly used to propel spacecraft can be employed to produce a collimated plasma beam and point it towards the body. The fact that the beam can be generated on a "shepherd" spacecraft placed in proximity of the target without physical attachment with the latter provides an interesting solution for space applications such as space debris removal and asteroid deflection. The Space Dynamics Groups of the Technical University of Madrid (SDG-UPM) is pioneer in exploring this concept by developing analytical and numerical control models in collaboration with the Electrical Propulsion and Plasma Team of the Carlos III University (EP2-UC3M) and the Advanced Concepts Team of the European Space Agency (ACT-ESA). The concept has also been proposed independently by JAXA and CNES.