  The next generation of ultra-high energy cosmic ray (UHECR) and very-high
energy neutrino observatories will address the challenge of the extremely low
fluxes of these particles at the highest energies. EUSO-SPB2 (Extreme Universe
Space Observatory on a Super Pressure Balloon2) is designed to prepare space
missions to address this challenge. EUSO-SPB2 is equipped with 2 telescopes:
the Fluorescence Telescope, which will point downwards and measure fluorescence
emission from UHECR air showers with an energy above 2EeV, and the Cherenkov
Telescope (CT), which will point towards the Earth's limb and measure direct
Cherenkov emission from cosmic rays with energies above 1PeV, verifying the
technique. Pointed below the limb, the CT will search for Cherenkov emission
produced by neutrino-sourced tau-lepton decays above 10PeV energies and study
backgrounds for such events. The EUSO-SPB2 mission will provide pioneering
observations and technical milestones on the path towards a space-based
multi-messenger observatory.
