Overview of the JEM-EUSO program for the study of ultra-high-energy cosmic-rays from space

TL;DR

The paper reviews the progress and technological developments of the JEM-EUSO program, which aims to observe ultra-high-energy cosmic rays from space to overcome limitations of ground-based detectors.

Contribution

It provides an overview of completed, ongoing, and proposed missions within the JEM-EUSO program for space-based UHECR observation.

Findings

Multiple missions have been completed, demonstrating key technologies.

The program has developed detectors capable of observing cosmic rays from space.

Future missions like POEMMA are under study for enhanced observations.

Abstract

Ultra High Energy Cosmic Rays (UHECRs) offer a unique chance to study the universe at energies inaccessible by man-made accelerators. Observations by ground based observatories have clarified several characteristics of these particles, but their origin, nature, and acceleration mechanisms are still unclear, mostly due to their extremely low flux. Space-based observatories have the potential for an increase in statistics, up to several orders of magnitude, and would be able to cover the whole sky, allowing for a direct comparison of spectra and direction of arrival, but the detector design poses several formidable technical challenges. The JEM-EUSO program has been addressing this problem, trying to open the road of space-based UHECR observations. Several missions have already been completed (on the ground: EUSO-TA; with stratospheric ballons: EUSO-Balloon, EUSO-SPB1 and EUSO-SPB2; in space: TUS\cite{Klimov2017}, MINI-EUSO). Others are under study (K-EUSO) or proposed for the next decade (POEMMA)\cite{Olinto_2021}. In this work we report on the status of the JEM-EUSO program and the technology developed so far.