EUSO-BALLOON: a Pathfinder for the Extreme Universe Space Observatory Mission*

EUSO-BALLOON is a pathfinder for the JEM-EUSO (Extreme Universe Space Observatory on the Japanese Experiment Module) mission which is being developed by an international collaboration of scientists from 15 countries. JEM-EUSO is designed to observe Ultra-High Energy Cosmic Ray-induced air showers by measuring the fluorescent and Cherenkov light they emit in the near ultraviolet. Video clips of the showers will be recorded and used to reconstruct the energies and arrival directions of the cosmic rays. EUSO-BALLOON will demonstrate the key JEM-EUSO technologies and techniques including an infrared camera to characterize the atmosphere. It will be flown on stratospheric balloons by the French Space Agency, CNES. The first flight will be in the summer of 2014. The instrument will point to the nadir from an altitude of about 40 km recording both showers and background transient luminous events. EUSO-BALLOON will monitor a 12 by 12 degree field of view. It is currently being integrated and tested at IRAP in Toulouse.