33 RD I NTERNATIONAL COSMIC RAY CONFERENCE,RIO DE JANEIRO 2013 THE ASTROPARTICLE PHYSICS CONFERENCE Space Mission Lomonosov on Study Gamma-Ray Bursts and UHECR A.M. AMELUSHKIN 1 , V.V. BENGHIN 1 , V.V. BOGOMOLOV 1 , G.K. GARIPOV 1 , E.S. GORBOVSKOY 2 , B. GROSSAN 3 , A.F. I YUDIN 1 , B.A. KHRENOV 1 , P.A. KLIMOV 1 , J. LEE 4 , V.M. LIPUNOV 2 , G. NA 4 , V.I. OSEDLO 1 , M.I. PANASYUK 1 , I.H. PARK 4 , V.L. PETROV 1 , S.A. SHARAKIN 1 ,YU.SHPRITS 5 , G.F. SMOOT 3 , S.I. SVERTILOV 1 , N.N. VEDENKIN 1 , I.V. YASHIN 1 1 Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow, Russia 2 Lomonosov Moscow State University, Shternberg Astronomical Institute, Moscow, Russia 3 Berkeley Center for Cosmological Physics, Berkeley, California, USA 4 Department of Physics, Sungkyunkwan University, Seobu-ro, Jangangu, Suwonsi, Gyeongido, 440-746, Korea 5 Institute of Geophysics and Planetary Physics, UCLA, 405 Hilgard Ave / 7127, Los Angeles, CA, USA. [email protected] Abstract: The main idea of Lomonosov space mission is to study extreme astrophysical phenomena in the Universe, such as cosmic gamma-ray bursts (GRB) and ultra-high energy cosmic rays (UHECR). GRB being one of the most powerful events in the Universe occur not only in gamma-range, but also in optics and UV. Due to unusually powerful brightness of GRBs, studying of their properties allows the researchers to look in the epoch of early Universe, i.e. to study evolution of stars and stellar populations with red shift starting from z ∼ 0.1. Other extreme phenomenon in the Universe is a flux of UHECR, which is most likely produced in Active Galactic Nuclei (AGN). The fundamental problem is to estimate maximal particle energy, to which they could be accelerated in such sources. AGN are very distant objects, UHECR go a long way before coming to the Earth. During their propagation UHECR lose energy due to photo-production of secondary particles (mostly pions) on the microwave background photons. It leads to a natural limit of observable cosmic ray particle energy, Greisen- Zatsepin-Kuzmin limit,and to UHECR energy spectrum cut-off at energy of about 5 · 10 19 eV. Studies of mentioned above problems of extreme phenomena dictate scientific objectives of large scale space experiment Lomonosov with a specific set of instruments: detectors of GRB in wide range of wavelengths (in optics, ultra-violet, X-rays and gamma-rays) and large aperture telescope for recording fluorescence light from the atmosphere generated by UHECR. Main parameters and brief description of these instruments are presented. Keywords: Lomonosov, UHECR, GRB. 1 Introduction Studies of extremely high energy and power processes such as GRB and UHECR are of great importance not only for understanding these phenomena, but also for developing theory of the early Universe. GRBs are observed as short (from dozens of milliseconds up to dozens of seconds) increases of gamma-quanta flux with quanta energies from 10 5 eV up to at least 10 9 eV. Discovered in 60s years of 20th century they are still at the cutting edge of astrophysics. These phenomena being the most powerful in the Universe occur not only in gamma- range, but also in optics and UV. The power of the explosion of these most bright astrophysical objects achieves 10 51 – 10 53 erg/s. GRB optical emission lasts up to several hours or even days, it can be an evidence of afterglow which appears after a giant explosion in the external shock wave expanding in the interstellar space and stellar wind of the exploded star. Probably, it is a process of collapse of a fast-rotating very massive star to a black hole in the case of so-called long- duration (more than a few seconds) bursts or merging of a neutron stars in tight binary system in the case of so-called short-duration (less than a second) bursts. However, those models are under discussion and nature of this extraordinary phenomenon is still unknown. Due unusually powerful brightness of GRBs, studying of their properties allows researchers to look in epoch of the early Universe, i.e. to study evolution of stars and stellar populations within the wide range of red shift from z ∼ 0.1 up to z ∼ 15–20, which is more than 98% of age of the Universe. The other extreme phenomena in the Universe are ultra- high energy cosmic rays, which are most likely produced by the Active Galactic Nuclei (AGN). The fundamental prob- lem is to estimate maximal particle energy, to which they could be accelerated in such sources, and whether there is a maximum energy to which particles can be accelerated anywhere in the Universe. Because AGN are very distant objects, UHECR go a long way before coming to the Earth. During their propagation UHECR lose energy due to photo- production of secondary particles (mostly pions) on the mi- crowave background photons. It leads to a natural limit of observable cosmic ray particle energy and to UHECR en- ergy spectrum cut-off at the photo-production energy thresh- old, i.e. about 5 · 10 19 eV (Greisen-Zatsepin-Kuzmin cut- off). However, at present we have only limited and contra- dictory information from ground-based experimental arrays about the energy spectrum and composition of cosmic parti- cles at extremely high energies. UHECR detectors on board of satellites promise to get new and rich information in this interesting field of science [1, 2, 3, 4].