Normally antennas have a curved reflector dish - which works like the rounded surrounding of a flashlight to focus its beam towards its target - as well as a radio signal feed horn. It is one of the most distinctive elements of a spacecraft – and often among the most bulky. ESA scientists have developed new technology that allows them to design and build antennas with equivalent capabilities, but in two instead of three dimensions. The result is a flat antenna that is much lighter and easier to accommodate on a mission, while doing the same job as a curved antenna. The technology is called ‘modulated metasurface’: electromagnetic radiation is influenced not by the curvature of the antenna surface but through careful tailoring of the surface itself. Thousands of small metal patches of different sizes and orientations are arranged on top of a dielectric layer across the face of the antenna, through which EM radiation is fed through a single central feeding point.