The EUSO-Balloon pathfinder

Abstract

EUSO-Balloon is a pathfinder for JEM-EUSO, the Extreme Universe Space\ud Observatory which is to be hosted on-board the International Space\ud Station. As JEM-EUSO is designed to observe Ultra-High Energy Cosmic\ud Rays (UHECR)-induced Extensive Air Showers (EAS) by detecting their\ud ultraviolet light tracks ``from above{''}, EUSO-Balloon is a\ud nadir-pointing UV telescope too. With its Fresnel Optics and\ud Photo-Detector Module, the instrument monitors a 50 km(2) ground surface\ud area in a wavelength band of 290-430 nm, collecting series of images at\ud a rate of 400,000 frames/sec. The objectives of the balloon demonstrator\ud are threefold: a) perform a full end-to-end test of a JEM-EUSO prototype\ud consisting of all the main subsystems of the space experiment, b)\ud measure the effective terrestrial UV background, with a spatial and\ud temporal resolution relevant for JEM-EUSO. c) detect tracks of\ud ultraviolet light from near space for the first time. The latter is a\ud milestone in the development of UHECR science, paving the way for any\ud future space-based UHECR observatory. On August 25, 2014, EUSO-Balloon\ud was launched from Timmins Stratospheric Balloon Base (Ontario, Canada)\ud by the balloon division of the French Space Agency CNES. From a float\ud altitude of 38 km, the instrument operated during the entire\ud astronomical night, observing UV-light from a variety of ground-covers\ud and from hundreds of simulated EASs, produced by flashers and a laser\ud during a two-hour helicopter under-flight

The onboard software of the EUSO‐SPB pathfinder experiment

“… The EUSO‐TA experiment aimed to demonstrate the capability of a UV telescope with a conceptual design similar to the one to be located on the ISS in detecting air showers. It is ground based and has been installed at the Telescope Array site in the desert of Utah, USA, in 2013 and it is still in operation, with ongoing plans to upgrade it. The EUSO‐Balloon experiment launched on a stratospheric balloon in August 2014, from Timmins (Canada, Ontario), was an engineering mission with the aim of increasing the Technical Readiness Level (TRL) of the hardware in near‐space conditions and performing an estimation of the UV background by observing the Earth's UV emission from the sky. The EUSO‐SPB experiment is the evolution of EUSO‐Balloon; it was designed for a long duration balloon mission using a Super‐Pressure Balloon technology. It was launched by NASA on April 24, 2017 from Wanaka, New Zealand.…”

The JEM-EUSO mission: An introduction

“…The instrument has been built by the JEM-EUSO collaboration. EUSO-Balloon is an imaging The first flight was launched on August 25, 2014, from the Timmins Stratospheric Balloon Base in Canada, in a CNES balloon campaign [27] (Fig. 7).…”

“…The background was measured under several conditions and although no cosmic ray tracks were detected, the instrument was able to detect artificial UV tracks induced by a laser beam shot from a helicopter flying in the field of view of the balloon. The main features of the instrument and mission, together with several results of the first flight, are summarised in [27]. Given the success of the first flight, the EUSO-Balloon program will continue with future flights.…”

EUSO-TA – First results from a ground-based EUSO telescope

“…The first observations in EUSO family has been performed with an on-ground EUSO-TA experiment, the main focus of this paper. Then a flight of EUSO-BALLOON, with similar design, followed in 2014 [2], that successfully observed laser-simulated EAS, LED flashes and night-time UV background of Earth. In 2017 a super pressure balloon with upgraded electronics -EUSO-SPB -has flown with an aim of observing UV light from EAS looking down at the atmosphere for the first time in history.…”