The complexity of modern cosmic ray observatories and the rich data sets they capture often require a sophisticated software framework to support the simulation of physical processes, detector response, as well as reconstruction and analysis of real and simulated data. Here we present the EUSO-(Off) over bar(line) under bar framework. The code base was originally developed by the Pierre Auger Collaboration, and portions of it have been adopted by other collaborations to suit their needs. We have extended this software to fulfill the requirements of Ultra-High Energy Cosmic Ray detectors and very high energy neutrino detectors developed for the Joint Exploratory Missions for an Extreme Universe Observatory (JEM-EUSO). These path-finder instruments constitute a program to chart the path to a future space-based mission like POEMMA. For completeness, we describe the overall structure of the framework developed by the Auger collaboration and continue with a description of the JEM-EUSO simulation and reconstruction capabilities. The framework is written predominantly in modern C++ (compliled against C++17) and incorporates third-party libraries chosen based on functionality and our best judgment regarding support and longevity. Modularity is a central notion in the framework design, a requirement for large collaborations in which many individuals contribute to a common code base and often want to compare different approaches to a given problem. For the same reason, the framework is designed to be highly configurable, which allows us to contend with a variety of JEM-EUSO missions and observation scenarios. We also discuss how we incorporate broad, industry-standard testing coverage which is necessary to ensure quality and maintainability of a relatively large code base, and the tools we employ to support a multitude of computing platforms and enable fast, reliable installation of external packages. Finally, we provide a few examples of simulation and reconstruction applications using EUSO-(Off) over bar(line) under bar.

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~hours 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 approximately 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.

This is a collection of papers presented by the JEM-EUSO Collaboration at the 38th International Cosmic Ray Conference (Nagoya, Japan, July 26-August 3, 2023)

JEM-EUSO is an international program for the development of space-based Ultra-High Energy Cosmic Ray observatories. The program consists of a series of missions which are either under development or in the data analysis phase. All instruments are based on a wide-field-of-view telescope, which operates in the near-UV range, designed to detect the fluorescence light emitted by extensive air showers in the atmosphere. We describe the simulation software ESAF in the framework of the JEM-EUSO program and explain the physical assumptions used. We present here the implementation of the JEM-EUSO, POEMMA, K-EUSO, TUS, Mini-EUSO, EUSO-SPB1 and EUSO-TA configurations in ESAF. For the first time ESAF simulation outputs are compared with experimental data.

The time distributions of particles in extensive air showers (EASs) have been studied using the EAS array at Moscow State University [1, 2]. More than 10(5) particles are produced in an EAS during the interac- tion of cosmic rays with energies above 10(14) eV with the atmosphere. Delayed particles are detected in 3.5% of EASs with an unshielded detector located at the Earth's surface. Muons are detected in 60% of EASs using a shielded detector located under a soil ground layer equivalent to a 20 m of water column. The detector signals are recorded using a two-beam analog storage oscilloscope. It has been found that the detection probability increases when observing muons for EASs containing from 10(5) to 10(6) particles, and when observing delayed particles for EASs containing from 10(6) to 10(7) particles. The distribution over distances to the EAS axis when observing delayed particles is wider than for muons and the age distributions do not differ within errors. The features of EASs with delayed particles and the hypothesis that the height of the appearance of delayed particles can be higher than the height at which EAS electrons and muons are produced are considered.

Compilation of papers presented by the JEM-EUSO Collaboration at the 37th International Cosmic Ray Conference (ICRC), held on July 12-23, 2021 (online) in Berlin, Germany.

The number of experiments on-board Lomonosov spacecraft are preparing now at SINP MSU in co-operation with other organisations. The main idea of Lomonosov mission is to study extreme astrophysical phenomena, such as cosmic gamma-ray bursts and ultra-high energy cosmic rays. These phenomena connect with processes occurred in very distant astrophysical objects of the Early Universe and give us information about first stages of Universe evolution. Thus, the Lomonosov mission scientific equipment includes several instruments for gamma-ray burst observation in optics, ultra-violet, X-rays and gamma-rays and the wide aperture telescope for ultra-high energy particle study by detection of ionisation light along its tracks in the atmosphere. The main parameters and a brief description of these instruments are presented.

TUS (Tracking Ultraviolet Set-up) is the world's first orbital detector of ultra-high-energy cosmic rays (UHECRs). It was launched into orbit on 28th April 2016 as a part of the scientific payload of the Lomonosov satellite. The main aim of the mission was to test the technique of measuring the ultraviolet fluorescence and Cherenkov radiation of extensive air showers generated by primary cosmic rays with energies above ∼100 EeV in the Earth atmosphere from space. During its operation for 1.5 years, TUS registered almost 80,000 events with a few of them satisfying conditions anticipated for extensive air showers (EASs) initiated by UHECRs. Here we discuss an event registered on 3rd October 2016. The event was measured in perfect observation conditions as an ultraviolet track in the nocturnal atmosphere of the Earth, with the kinematics and the light curve similar to those expected from an EAS. A reconstruction of parameters of a primary particle gave the zenith angle around 44̂ but an extreme energy not compatible with the cosmic ray energy spectrum obtained with ground-based experiments. We discuss in details all conditions of registering the event, explain the reconstruction procedure and its limitations and comment on possible sources of the signal, both of anthropogenic and astrophysical origin. We believe this detection represents a significant milestone in the space-based observation of UHECRs because it proves the capability of an orbital telescope to detect light signals with the apparent motion and light shape similar to what are expected from EASs. This is important for the on-going development of the future missions KLYPVE-EUSO and POEMMA, aimed for studying UHECRs from space.

The MEMSTEL (Micro Electro Mechanical Systems Space Telescope) is a space-based experiment being designed to investigate the origin of extreme energy cosmic-ray (EECR) particles above 5 × 10 eV. The fluorescent light generated in extensive air showers (EAS) when EECRs hit the atmosphere can be detected from low Earth orbit. MEMSTEL will implement a novel idea of a tracking mirror based on semiconductor MEMS technology. The light signal will be focused on a relatively small area of readout photo-sensors using a tracking mirror. One candidate for MEMSTEL photo-sensors is the conventional multi-anode photo multiplier tube (PMT). Recently, a new type of photo-sensor was developed for particle detector readouts the silicon photo multiplier (Si-PM). This compact photo-sensor is comprised of a large array of micro-cells operating in a limited Geiger mode, and provides high gain (~ 10) with low operating voltage (~ 50 V). The compact design, light weight and low power consumption make this device an excellent photon-detector candidate for space-based experiments. In this paper, we report on the comparative performance of a 1 × 1mm Si-PM, a conventional PMT, and a Hybrid Photo Diode (HPD) in lab tests, reading out light generated by Light Emitting Diode (LED) as well as by scintillating fibers excited with a radioactive source.

The results obtained by studying temporal distributions of particles of energy in excess of 5 GeV in extensive air showers (EAS) of energy above $$10^{15}$$ eV at distances shorter than 200 m from the EAS axis with the aim of searches in data from the MSU EAS setup for delayed and advanced new particles that could arise in the interactions of primary cosmic rays in the Earth’s atmosphere are presented. These investigations were performed with the aid of an unshielded ground-based detector and an underground detector shielded by a ground layer 20 m.w.e. thick. It is shown that delayed particles having a delay time between 100 and 300 ns and an exponentially descending temporal distribution with an exponent of 120 ns exhibit a higher ionizing ability than relativistic muons. The flow of such particles is attenuated by the ground layer between the unshielded and shielded detectors by a factor of about 30. Particles moving ahead of the EAS disk were not detected in the present study. Properties of delayed particles are discussed. Special features of calibrations and auxiliary tests confirming data from the present measurements are analyzed.

The search for microorganisms in cosmic bodies of the Solar System is of great importance for understanding the problem of the origin of life. At present, it is difficult to create specialized laboratories searching for living microorganisms on the surface of planets or cosmic bodies that either formed in the Solar System or were captured by the Solar gravity from interstellar space. Existing experiments on search for life on landers and planet research vehicles allow this research to be conducted on the surface of planets and their satellites, but on a limited area near the landing site. This paper considers a method of remote sensing of outer space by light flashes of cosmic objects to detect bioactivity on almost all of their surfaces. The presence of bioactivity is the detected by specific luminescence of microorganisms when they are illuminated by probing radiation that causes their fluorescence.

Tracking Ultraviolet Setup (TUS) detector is a detector of ultraviolet (UV) radiation of the atmosphere in the wavelength range of 300–400 nm (near-ultraviolet) with high sensitivity (tens of photons emitted within the solid angle of 10–4 sr in 0.8 μs), which operated for a year and a half aboard the Lomonosov satellite. The TUS telescope had a multipurpose operational program, which made it possible to detect UV flashes from the shortest ones created by extensive air showers generated by cosmic rays to long ones, up to 1 s, created by meteors. Among these various phenomena, most often are flashes from lightning strikes, both directly creating a glow and causing the development of secondary discharges in the atmosphere, in the upper atmosphere and in the ionosphere. These discharges differ in both nature and phenomenology—in particular, they have different durations and luminosities.

The natural and “man-made” space environment generates serious risks for the implementation of space missions, both automatic and human. The main natural and technogenic risk factors that limit or pose a threat to the implementation of space-based automatic and manned space missions in the near-Earth space are cosmic radiation and space debris. In the upper layers of the atmosphere, natural transient electromagnetic phenomena associated with significant energy release are also risk factors for suborbital flights. It is planned to create a system of spacecraft in the proposed “Universat-SOCRAT” project that makes it possible, in a mode close to real-time, to determine the radiation conditions in a significant part of the area of trapped radiation, up to the orbits of global navigation satellite systems or the geostationary orbit. It is also planned to create a space segment of monitoring space debris and electromagnetic transients in the upper atmosphere. Monitoring of space debris will allow all-weather and global tracking of near-Earth objects and, thereby, increase the efficiency of analyzing data and making necessary decisions. In some cases it will improve the accuracy of determining the coordinates of objects for their subsequent cataloging. Successful realization of the project will make it possible to create a space system for monitoring and preventing space hazards for both ongoing and planned space missions for the first time in the world.

TUS (Tracking Ultraviolet Set-up) is the world’s first orbital detector of ultra-high-energy cosmic rays (UHECRs). It was launched into orbit on April 28, 2016, as a part of the scientific payload of the Lomonosov satellite. The main aim of the mission was to test the technique of measuring the ultraviolet fluorescence and Cherenkov radiation of extensive air showers generated by primary cosmic rays with energies above ∼ 100 EeV in the nocturnal atmosphere of the Earth from space. During its operation period, TUS registered almost 80,000 events, with a few of them satisfying the criteria expected for UHECR candidate events. Here we discuss the phenomenology and possible interpretations of an outstanding event registered in perfect observational conditions on October 3, 2016.

The JEM-EUSO (Joint Experiment Missions for the Extreme Universe Space Observatory) program aims at developing Ultra-Violet (UV) fluorescence telescopes for efficient detections of Extensive Air Showers (EASs) induced by Ultra-High Energy Cosmic Rays (UHECRs) from satellite orbit. In order to demonstrate key technologies for JEM-EUSO, we constructed the EUSO-Balloon instrument that consists of a similar to 1 m(2) refractive telescope with two Fresnel lenses and an array of multi-anode photo-multiplier tubes at the focus. Distinguishing it from the former balloon-borne experiments, EUSO-Balloon has the capabilities of single photon counting with a gate time of 2.3 mu s and of imaging with a total of 2304 pixels. As a pathfinder mission, the instrument was launched for an 8 h stratospheric flight on a moonless night in August 2014 over Timmins, Canada. In this work, we analyze the count rates over similar to 2.5 h intervals. The measurements are of diffuse light, e.g. of airglow emission, back-scattered from the Earth's atmosphere as well as artificial light sources. Count rates from such diffuse light are a background for EAS detections in future missions and relevant factor for the analysis of EAS events. We also obtain the geographical distribution of the count rates over a similar to 780 km(2) area along the balloon trajectory. In developed areas, light sources such as the airport, mines, and factories are clearly identified. This demonstrates the correct location of signals that will be required for the EAS analysis in future missions. Although a precise determination of count rates is relevant for the existing instruments, the absolute intensity of diffuse light is deduced for the limited conditions by assuming spectra models and considering simulations of the instrument response. Based on the study of diffuse light by EUSO-Balloon, we also discuss the implications for coming pathfinders and future space-based UHECR observation missions. (C) 2018 Published by Elsevier B.V.

Compilation of papers presented by the JEM-EUSO Collaboration at the 36th International Cosmic Ray Conference (ICRC), held July 24 through August 1, 2019 in Madison, Wisconsin.

EUSO-TA is a ground-based telescope, installed at the Telescope Array (TA) site in Black Rock Mesa, Utah, USA. This is the first detector to successfully use a Fresnel lens based optical system and multi-anode photomultipliers (64 channels per tube, 2304 channels encompassing a 10.6 degrees x 10.6 degrees field of view) for detection of Ultra High Energy Cosmic Rays (UHECR). The telescope is located in front of one of the fluorescence detectors of the TA experiment. Since its installation in 2013, the detector has observed several ultra-high energy cosmic ray events and, in addition, meteors. The limiting magnitude of 5.5 on summed frames (similar to 3 ms) has been established. Measurements of the UV night sky emission in different conditions and moon phases and positions have been completed. The performed observations serve as a proof of concept for the future application of this detector technology. (C) 2018 Elsevier B.V. All rights reserved.