Mini-EUSO: a pathfinder for JEM-EUSO to measure Earth's UV background from the ISS

For any experiment aiming at the observation of Ultra High Energy Cosmic Rays(UHECR) from space, one key measurement is related to the UV background produced in Earth atmosphere. In view of the planned missions (KLYPVE/K-EUSO, JEM-EUSO) at the International Space Station(ISS), a small, compact UV telescope, Mini-EUSO, aiming at the study of the UV night emissions from Earth, is being developed by the JEM-EUSO International Collaboration to be placed at the transparent, nadirlooking UV window of the Russian module of the ISS. Mini-EUSO is a mission approved by the Italian Space Agency (ASI) and, under the name ”UV atmosphere”, by the Russian Space Agency Roscosmos. Scientific, technical and programmatic aspects of this project will be described.