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The Extreme Universe Space Observatory on a Super Pressure Balloon II Mission (EUSO-SPB2) is a precursor for a next generation space observatory for multi-messenger astrophysics. The EUSO-SPB2 instrument will measure PeV and EeV-scale cosmic rays, optical backgrounds that could mimic tau neutrino interactions in the Earth’s limb, and search for optical signatures consistent with the upward-going candidate events that the Antarctic Impulse Transient Antenna (ANITA) reported.

The payload, now in the design and fabrication stage, features a pair of optical telescopes that have 1 meter diameter apertures. The Fluorescence Telescope will have sensitivity in the UV to target extensive air showers at EeV energies. The Cherenkov Telescope will have UV/VIS sensitivity to target Cherenkov emission from air showers at PeV energies. The balloon was successfully launched on May 13, 2023 at Wanaka, New Zealand.

Reference: EUSO-SPB2 paper at ICRC2021 ( and at ICRC2023 (

The EUSO-SPB2 payload including gondola structure shown in a preliminary configuration, telescopes, solar panels, antennas, and ballast hoppers.