JUICE - JUpiter ICy moons Explorer - is the first large mission in the ESA Cosmic Vision 2015-2025 programme. The mission was selected in May 2012.Due to launch in June 2022 and to arrive at Jupiter in October 2029, it will spend at least three ½ years making detailed observations of Jupiter and three of its largest moons, Ganymede, Callisto and Europa. The focus of the mission is to characterise the conditions that might have led to the emergence of habitable environments among the Jovian icy satellites. Studies of Jupiter’s atmosphere and magnetosphere, their interaction with the Galilean satellites, minor moons and rings will further enhance our understanding of the evolution and dynamics of the Jovian system. The payload consists of 10 state-of-the-art instruments plus one experiment that uses the spacecraft telecommunication system with ground-based instruments. The presentation will address the science objectives, mission design, spacecraft, payload, challenges and the trajectory of the JUICE mission.