Lightning is an extremely energetic electric discharge process in our atmosphere. It significantly affects the concentration of greenhouse gases and it threatens electrical and electronic devices, in particular, when placed on elevated structures like wind turbines or aircraft, and when these structures are built with modern composite materials with inherently low electric conductivity. In addition, even our fundamental understanding of atmospheric electricity is far from complete. New discharge processes in the atmosphere above thunderstorms have been discovered, the so-called Transient Luminous Events (TLEs) in the stratosphere and mesosphere, and Terrestrial Gamma-ray Flashes (TGFs) that emit particle beams of antimatter. These phenomena demand thorough investigations, in geophysics and in the related fields of plasma and high-voltage technology where similar discharges appear.These challenges are approached within the SAINT project with a multidisciplinary and inter-sectorial training platform for 15 ESRs. The platform brings together satellite and ground observations with modelling and lab experiments. It couples scientific studies to applications relevant to industries developing satellite data products, plasma discharge technologies, lightning detection systems and lightning protection devices. With SAINT, we take advantage of the extraordinary opportunity presented by three simultaneous space missions with dedicated instruments to study lightning discharges, TLEs and TGFs, to integrate the unique space data with dedicated novel ground observations, model developments and lab experiments. SAINT will train the next generation of young, innovative scientists to shape the future of research and technology in Europe.