GRBAlpha, VZLUSAT-2 and GRBBeta -- GRB observations with CubeSats
Abstract
Results from GRBAlpha, VZLUSAT-2 and GRBBeta CubeSats and their on-board gamma-ray detectors for monitoring transients are summarised in this article. GRBAlpha was a 1U CubeSat launched in March 2021 to a 550 km altitude polar orbit carrying a CsI(Tl) scintillator gamma-ray burst (GRB) detector with a sensitive range of approximately 30-900 keV. It successfully operated for over four years until June 2025 when it de-orbited. VZLUSAT-2 was a 3U CubeSat launched in January 2022 to a 535 km altitude polar orbit and de-orbited in November 2025 after almost four years of smooth operation. It carried on board two GRB detectors very similar to the one used on GRBAlpha. Both missions have detected about 360 gamma-ray transients, including over 170 long and short gamma-ray bursts (GRBs), and including the most intense GRB ever recorded GRB 221009A and the second brightest GRB 230307A. The new family member, GRBBeta 2U CubeSat, integrated at Masaryk University, was launched in July 2024 to a 580 km altitude, 62 degree inclination orbit. It has been detecting GRBs since its launch without any trouble. Gamma-ray detectors on these nanosatellites are based on CsI(Tl) scintillator readout by silicon photomultipliers (SiPMs). These missions also provide a unique opportunity to study the radiation damage of SiPMs in the low Earth orbit environment and monitor the radiation belts. We have demonstrated that CubeSats can be used in missions lasting beyond three years and routinely detect GRBs.
Keywords
Cite
@article{arxiv.2601.16609,
title = {GRBAlpha, VZLUSAT-2 and GRBBeta -- GRB observations with CubeSats},
author = {Jakub Ripa and Marianna Dafcikova and Andras Pal and Norbert Werner and Masanori Ohno and Laszlo Meszaros and Filip Munz and Balazs Csak and Gabor Galgoczi and Nikola Husarikova and Tomas Vitek and Pavel Kosik and Michaela Duriskova and Martin Kolar and Lea Szakszonova and Michal Pazderka and Filip Hroch and Martin Topinka and Yasushi Fukazawa and Hiromitsu Takahashi and Tsunefumi Mizuno and Masato Yokota and Jean-Paul Breuer and Kazuhiro Nakazawa and Hirokazu Odaka and Yuto Ichinohe and Peter Hanak and Miroslav smelko and Ivo Vertat and Tomas Urbanec and Ales Povalac and Miroslav Kasal and Jakub Kapus and Jan Hudec and Marcel Frajt and Maksim Rezenov and Vladimir Daniel and Petr Svoboda and Juraj Dudas and Martin Sabol and Robert Laszlo and Martin Koleda and Hsiang-Kuang Chang and Tsung-Che Liu and Chih-Hsun Lin and Chin-Ping Hu and Che-Chih Tsao and Kaustubha Sen and Chih-En Wu and Aaron Tohuvavohu and Suresh Sivanandam and Mark Barnet},
journal= {arXiv preprint arXiv:2601.16609},
year = {2026}
}
Comments
10 pages, 3 figures, 1 table, conference: Multifrequency Behaviour of High Energy Cosmic Sources - XV (MULTIF2025), 9-14 June, 2025, Mondello, Palermo, Italy, accepted in Proceedings of Science, PoS(MULTIF2025)057