JEM-EUSO is a science mission to explore extremes of the Universe.　It observes the dark-side of the Earth and detects UV photons emitted from the giant air shower caused by an extremely high energy particle (about 10^20 eV). Such a particle arrives almost straightly through our Milky Way Galaxy and is expected to allow us to trace the source location by its arrival direction. This will open the door to the new astronomy with charged particles: JEM-EUSO can determine the arrival direction of the particles within several degrees and energy of them within 30%. In its five years operation including the tilt mode, JEM-EUSO will detect at least 1,000 events with E>7x10^19 eV and determine the energy spectrum of trans-GZK region with a statistical accuracy of several percent. JEM-EUSO is planned to be transported with HTV (H2 Transfer Vehicle) and attached to the Japanese Experiment Module/ Exposure Facility (JEM/EF) of International Space Station. JAXA released the call for proposals for the mission candidates of the second phase utilization of JEM/EF for the launch of 2011 and 2013. Two years of phase-A study will be carried out under JAXA for selected candidates. *the JEM-EUSO Collaboration: the list of authors is attached.

JEM-EUSO

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 5 (HE part 2), pages 1045-1048