The study of Ultra High Energy Cosmic Rays (UHECRs) offers unique possibilities to probe the energies currently inaccessible by man-made accelerators. The last years have shed light on several characteristics of these particles, but - due to their extremely low flux - their origin, nature and acceleration mechanisms are still unclear.

Space-based observations have a potential for a large increase in statistics and capability to cover the whole sky, allowing for a direct comparison of spectra and direction of arrival from different regions and sources. Even a relatively small detector, with the exposure of a few times that of Auger, would be able to clarify the differences between the Northern and Southern sky, confirm the existence of TA hot spot, and measure multipolar anisotropies with high precision.
To achieve this goal within the constraints of power, mass, size and bandwidth of space detectors, a number of novel technologies -- from optics to sensors, front-end and read-out electronics -- have been developed over the years. Several scaled versions of a large area space-borne telescope have been built: in August 2014 a balloon flight (EUSO-BALLOON) was successfully launched from Timmins (CA); since February 2015 a ground based detector (EUSO-TA) has been operating at the Telescope Array site in Utah. In 2017 a Super Pressure Balloon (EUSO-SPB) flew from Wanaka, New Zealand. In parallel, a series of missions have been realized by the Moscow State University to study the UV background and transient phenomena from night-time Earth: the Tatiana-1 and -2, Vernon, and TUS satellite-borne detectors. The next steps of the JEM-EUSO program include: a) MINI-EUSO -- a detector to be placed inside the International Space Station (2017); b) A second SPB flght, c) K-EUSO -- the first reflector based mission to perform UHECR science from space, paving the way to d) POEMMA, a Multi-Messenger devoted mission. In this work we discuss the current status of research and plans of the JEM-EUSO program.