EUSO-SPB1 mission and science
G. Abdellaoui, Shinsuke Abe, Jenni Adams, D. Allard, Gustavo Alonso, Luis A. Anchordoqui, A. Anzalone, Enrico Arnone, Katsuaki Asano, R. Attallah, H. Attoui, M. Ave Pernas, Renate Bachmann, S. Bacholle, M. Bagheri, Mohammed Bakiri, J. Baláz, D. Barghini, S. Bartocci, Matteo Battisti, J. Bayer, B. Beldjilali, T. Belenguer, N. Belkhalfa, R. Bellotti, А. А. Белов, K. Benmessaï, М. Бертаина, P. F. Bertone, Peter L. Biermann, L. Conti, C. Blaksley, Nicolas Blanc, S. Blin-Bondil, P. Bobík, M. Bogomilov, Karl Bolmgren, E. Bozzo, Susana Briz, A. Bruno, K.S. Caballero, F. Cafagna, G. Cambié, D. Campana, J. N. Capdevielle, Francesca Capel, A. Caramete, L. Caramete, R. Caruso, M. Casolino, Claudio Cassardo, A. Castellina, O. Catalano, A. Cellino, K. Černý, M. Chikawa, Gabriel Chiritoi, M. J. Christl, Roberta Colalillo, L. Conti, G. Cotto, H.J. Crawford, Roberto Cremonini, A. Creusot, Austin Cummings, A. de Castro Gónzalez, C. De La Taille, L. del Peral, Julianna Desiato, A. Diaz Damian, Rebecca Diesing, P. Dinaucourt, A. Djakonow, T. Djemil, A. Ebersoldt, Toshikazu Ebisuzaki, Johannes Eser, Francesco Fenu, Secundino Fernández, S. Ferrarese, George Filippatos, William A. Finch, C. Fornaro, M. Fouka, A. Franceschi, Sebastián Franchini, C. Fuglesang, Toshihiro Fujii, M. Fukushima, P. Galeotti, Eduardo García‐Ortega, D. Gardiol, G. Garipov, Estíbaliz Gascón, Eliza Gazda, Ján Genči, Alessio Golzio, P. Gorodetzky, Richard B. Gregg, Anne M. Green
Abstract
The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of ⪆3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search.