Phenomena have been observed in mountain high-energy cosmic-ray experiments, namely, a delayed absorption of high-energy cascades initiated by cosmic-ray hadrons in a lead absorber at $E_0\gtrsim {10}^{14} \mathrm{e}\mathrm{V}$ (so-called long-flying component), a coplanarity of most energetic particles in the central region of γ-ray−hadron superfamilies, and the so-called Tien Shan effect in EAS cores at $E_0\gtrsim {10}^{16} \mathrm{e}\mathrm{V} \left(\sqrt{s}>5 \mathrm{T}\mathrm{e}\mathrm{V}\right)$. These effects are not described by theoretical models. The coplanarity is explained by the process of coplanar generation of most energetic secondary particles in interactions of superhigh-energy hadrons with the nuclei of air atoms. The other two phenomena are possibly explained with a high cross section for fragmentation-region charmed-hadron generation. To investigate these phenomena, a cosmic-ray detector array, including a very thick ionization calorimeter, is being upgraded to study EAS cores.

"HADRON-55" with scintillation detectors and ionization calorimeters is used for studies in high-energy gamma-astronomy and cosmic ray physics. The "HADRON-55" consists of two parts - the upper gamma block and the lower hadron block. The gamma block absorbs and detects the electron-photon components of cosmic rays, while hadrons are not absorbed when they pass through the gamma block and begins to form particles in the hadron block. Project's main idea is to select events where there is the interaction in gamma block and no interaction in hadron block. Analysis of experiments results on "HADRON-55" accounts for ~ 6% of such events. The peripheral part of "HADRON-55" consists of 8 scintillation detectors placed in 2 circles with radii of 40 and 100 m. Over 4 years, more than 120,000 events with high energy of 10¹⁵ eV were detected.

The study describes the experimental complex of the station located in the Tien Shan mountains at an elevation of 3340 m above sea level. The complex consists of detectors of different types scattered across the station area, such as scintillation particles detectors, Cherenkov detectors, radio emission detectors for the measurement of the electron component of extensive air showers (EAS) created by the (1–1000) PeV cosmic ray particles, an ionization calorimeter and neutron detectors for the study of the nuclear-active component of EAS cores, and the underground particle detectors for the detection of cosmic ray muons. The data acquisition system allows the simultaneous recording of parameters from various stand-alone detectors registering an EAS, and storage of the acquired data in the database. As an illustration of research capability, the results of the EAS study are presented here which were obtained during the last few years at the different experimental set-ups constituting the Tien Shan complex.

Tien Shan High-Altitude Scientific Station is located at an altitude of 3340 m above sea level at a distance of 30 km from the city of Almaty. The station conducted a wide range of research projects. One of them is the "Hadron-55" complex with the help of which various effects and phenomena associated with the EAS passing through the Earth's atmosphere are studied. The installation includes a network of neutron monitor, ionization calorimeters, a system of scintillation detectors. In addition, the station contains such complexes as ALMAREC, which studies radio signals from EAS and an acoustic recording system that allows recording possible acoustic effects when muons pass through the earth's crust. Scientific station "Space Station" is one of the best in the CIS.