The Program

fig-missionJEM-EUSO is a new type of observatory to be attached at the International Space Station or orbiting as a free flyer, based on a UV very large telescope, which uses the whole Earth as detector. It will observe, from an altitude of several hundreds of km, the fluorescence tracks produced at (330-400) nm by Extensive Air Showers (EAS)  originated by UHE primaries which traverse the Earth’s atmosphere at ultra-relativistic speed.

JEM-EUSO will be operated for three years in Nadir configuration to maximize statistics at the lowest energies in order to cross calibrate with the current generation of ground-based detectors. The instrument will be then tilted (about 30°) with respect to Nadir in order to exploit a larger amount of atmosphere and to maximize the statistics of events at the highest energies. JEM-EUSO will significantly increase the exposure to UHECRs compared to the largest ground-based air shower arrays presently in operation.

At present the JEM-EUSO program involves the realization of small different fluorescence detectors already installed or to be installed on ground (EUSO-TA), on board stratospheric balloons for short (EUSO-Balloon) or long duration (EUSO-SPB) flights, inside the International Space Station (Mini-EUSO) and of a much larger detector to be attached outside the ISS (K-EUSO).

The final goal of the JEM-EUSO program is to send in orbit an experiment with a year time exposure more of one order of magnitudine of Auger.