The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) Mission: summary and some first results*

The Extreme Universe Space Observatory on a Super Pressure Balloon II (EUSO-SPB2) was launched as an Ultra Long Duration Balloon (ULDB) mission of opportunity flight May 13th , 2023, from Wanaka NZ. Its science objectives were to search for PeV energy neutrinos, observe PeV and EeV cosmic rays, measure backgrounds, and explore new techniques as a pathfinder toward the Probe of Extreme Multi-Messenger Astrophysics (POEMMA) space observatory. The payload featured two astroparticle telescopes and an IR cloud camera. All were field-tested in the Utah desert prior to launch. A fluorescence telescope was pointed down to measure EeV-energy cosmic rays. A Cherenkov telescope pointed toward the earth's limb measure PeV energy air showers. In flight it was tilted a few degrees above the limb to explore Cherenkov emission from PeV cosmic-rays and tilted a few degrees below the limb to search for air showers induced through neutrino interactions in the earth's limb. The gondola could be rotated in azimuth to aim the CT at neutrino candidate sources. Unfortunately, the flight was terminated in the Pacific Ocean 36 hours after launch due to a balloon leak. Despite this setback, both telescopes collected data and the mission achieved the first observation of PeV cosmic ray air-showers from near-space. This presentation will summarize the mission and present some first results. Planning for a follow-up flight, POEMMA Balloon Radio (PBR), is in progress.