Gagarin Research and Test Cosmonaut Training Center

Research into the mechanisms by which gravity influences spermatozoa has implications for maintaining the species in deep space exploration and may provide new approaches to reproductive technologies on Earth. Changes in the speed of mouse spermatozoa after 30 min exposure to simulated weightlessness (by 3D-clinostat) and 2 g hypergravity (by centrifugation) were studied using inhibitory analysis. Simulated microgravity after 30 min led to an increase in the speed of spermatozoa and against the background of an increase in the relative calcium content in the cytoplasm. This effect was prevented by the introduction of 6-(dimethylamino) purine, wortmannin, and calyculin A. Hypergravity led to a decrease in the speed of spermatozoa movement, which was prevented by sodium orthovanadate and calyculin A. At the same time, under microgravity conditions, there was a redistribution of proteins forming microfilament bundles between the membrane and cytoplasmic compartments and under hypergravity conditions—proteins forming networks. The obtained results indicate that even a short exposure of spermatozoa to altered gravity leads to the launch of mechanotransduction pathways in them and a change in motility.

This paper presents the first results of the study of changes in microcirculatory-tissue systems functioning under spaceflight conditions.

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Dust acoustic waves were investigated in an experiment under microgravity conditions, using the European Space Agency-Roscosmos facility PK-4 on the International Space Station. A three-dimensional dust cloud was confined in a glow-discharge plasma powered by a radio-frequency coil in low-pressure neon gas. Low-frequency dust acoustic waves (DAWs) were spontaneously excited due to the flowing ions in the plasma. Dust motion was imaged using video cameras, yielding the position for individual dust particles. Besides these particle-level measurements, the dust was also measured as a fluid continuum to obtain its velocity and density fluctuations. A space–time diagram of the dust-fluid velocity reveals that the waves changed properties as they propagated across the dust cloud, in the direction of the ion flow. Density fluctuations were characterized by a wave spectrum, indicating the emergence of collective vibration modes in a broad range of wave numbers. The decay of the modes was characterized by density correlation functions. Fitting the correlation functions to an analytical model yields an experimental measurement of the dispersion relation for DAWs, which is compared to that of linear theory.

The article discusses the possibility of synthesizing highly filled polymer composites based on polystyrene and titanium hydride. The composites were prepared by solid-phase compaction at high specific pressure. For uniform distribution, titanium hydride was preliminarily milled in a jet-vortex mill. The particle size of titanium hydride after grinding is in the range from 0.1 to 107 μm. The modal particle diameter is 35.41 μm, and the specific surface area of the particles is 15279 cm2 / cm3. The titanium hydride content in the composites did not exceed 60 wt%. The article presents data on the density and microhardness of the obtained composites. It was found that the introduction of titanium hydride increases the physicomechanical characteristics of the composites. The Vickers microhardness of a pure polystyrene sample is 19.87 ± 0.20 HV, and a sample containing 60 wt% titanium hydride is 36.17 ± 0.78 HV (at a load of 200 g).

The paper represents the ISS crew for Expedition 60/61/62 as well as main tasks and results of training. The great attention is paid to the results of the crew’s activities aboard the “Soyuz MS-15” manned transport vehicle (MTV) and International Space Station (ISS). The preliminary analysis of the implementation of the Russian scientific applied research and experiments is made. Extravehicular operations (EVA) under the programs of the ISS USOS are also briefly represented.