Pub Date : 2021-01-01DOI: 10.15407/knit2021.04.021
А. Stenin, V. Pasko, I. G. Drozdovych, M. O. Soldatova, U. Kyiv
This paper considers the problem of optimal fuel consumption damping of sudden deviations of angular velocities of an axisymmetric spacecraft with a constant speed of rotation around the main axis of symmetry. This assumption has some practical significance and may be due to the creation of artificial gravity on the spacecraft. The idea of artificial gravity due to the rotation of an axisymmetric cylindrical spacecraft is based on the principle of equivalence of the force of gravity and the force of inertia. The urgency of the fuel consumption optimization problem is due to the presence of its limited stock onboard the spacecraft. The optimization problem is solved based on the maximum principle and the phase plane method. The authors of the article determine the structure of optimal fuel consumption processes with three levels of control, and the number of their switches depends on the initial conditions. Synthesized on the phase plane, the optimal switching curves divide the phase plane into eight curvilinear quadrants, which uniquely determine the values of the optimal control effects by the current values of the deviations of the angular velocities of the spacecraft. The problem of the possible presence of a delay in the control loop is proposed to be solved based on the Bess compensation method. To do this, the corresponding optimal curves of switching and disabling the controls are built as geometric locations of points remoted for the time of delay from the found curves of switching and the beginning of coordinates accordingly. It allows us to avoid the emergence of steady self-oscillations in a control contour and to provide a condition of keeping the spacecraft in a given final state after the completion of the stabilization process. Depending on the technical equipment of the spacecraft, two variants of the optimal damping algorithm are offered, namely: an autonomous device in the onboard control system of the spacecraft in the absence of a sufficiently powerful onboard computer, or the optimal damping algorithm, implemented entirely in the onboard computer of the spacecraft in case of its sufficient power.
{"title":"Optimal damping of deviations of angular speeds of an eightsymetric space aircraft","authors":"А. Stenin, V. Pasko, I. G. Drozdovych, M. O. Soldatova, U. Kyiv","doi":"10.15407/knit2021.04.021","DOIUrl":"https://doi.org/10.15407/knit2021.04.021","url":null,"abstract":"This paper considers the problem of optimal fuel consumption damping of sudden deviations of angular velocities of an axisymmetric spacecraft with a constant speed of rotation around the main axis of symmetry. This assumption has some practical significance and may be due to the creation of artificial gravity on the spacecraft. The idea of artificial gravity due to the rotation of an axisymmetric cylindrical spacecraft is based on the principle of equivalence of the force of gravity and the force of inertia. The urgency of the fuel consumption optimization problem is due to the presence of its limited stock onboard the spacecraft. The optimization problem is solved based on the maximum principle and the phase plane method. The authors of the article determine the structure of optimal fuel consumption processes with three levels of control, and the number of their switches depends on the initial conditions. Synthesized on the phase plane, the optimal switching curves divide the phase plane into eight curvilinear quadrants, which uniquely determine the values of the optimal control effects by the current values of the deviations of the angular velocities of the spacecraft. The problem of the possible presence of a delay in the control loop is proposed to be solved based on the Bess compensation method. To do this, the corresponding optimal curves of switching and disabling the controls are built as geometric locations of points remoted for the time of delay from the found curves of switching and the beginning of coordinates accordingly. It allows us to avoid the emergence of steady self-oscillations in a control contour and to provide a condition of keeping the spacecraft in a given final state after the completion of the stabilization process. Depending on the technical equipment of the spacecraft, two variants of the optimal damping algorithm are offered, namely: an autonomous device in the onboard control system of the spacecraft in the absence of a sufficiently powerful onboard computer, or the optimal damping algorithm, implemented entirely in the onboard computer of the spacecraft in case of its sufficient power.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67116796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.05.035
O. Artemenko
The results of cytological, biochemical, and molecular biological studies clearly demonstrate the significant influence of microgravity on the main processes of plant development, revealing the mechanisms which underlie the reactions of plant responses to microgravity and ensure their adaptation to this factor. The key role in cell function belongs to the cytoplasmic membrane (CM). First of all, by its qualities and functions, it can play an important role in the adaptation of plants to microgravity. However, data about the effect of altered gravity on the physicochemical properties of CM are limited. Recently, much attention has been paid to the study of functional microdomains of the lipid bilayer that have a specific localization and content of lipids and proteins - lipid rafts. They are defined as a dynamic nanosized, sterol- and sphingolipid-enriched ordered association of specific proteins, in which a metastable resting state can be activated by a combination of specific lipid-lipid, protein-lipid, and protein-protein interactions. There are more and more experimental data that confirm their participation in such live processes as endocytosis, apoptosis, internalization of toxins, bacteria, viruses, etc., as well as their important role in the protective mechanisms of the cell under different stressors. In this work, a fluorescent marker of sterols – filipin and a fluorescent probe laurdan were used to confirm the presence of cholesterol and sphingolipid-enriched lipid ranges in CM. Our results regarding the increase in generalized polarization in the clinorotation conditions correlate with the data obtained in previous studies and indicate the sensitivity of the CM to a longer action of the clinorotation.
{"title":"The study of the functional state of lipid rafts in the cytoplasmic membrane of Pisum Sativum seedlings under clinorotation","authors":"O. Artemenko","doi":"10.15407/knit2021.05.035","DOIUrl":"https://doi.org/10.15407/knit2021.05.035","url":null,"abstract":"The results of cytological, biochemical, and molecular biological studies clearly demonstrate the significant influence of microgravity on the main processes of plant development, revealing the mechanisms which underlie the reactions of plant responses to microgravity and ensure their adaptation to this factor. The key role in cell function belongs to the cytoplasmic membrane (CM). First of all, by its qualities and functions, it can play an important role in the adaptation of plants to microgravity. However, data about the effect of altered gravity on the physicochemical properties of CM are limited. Recently, much attention has been paid to the study of functional microdomains of the lipid bilayer that have a specific localization and content of lipids and proteins - lipid rafts. They are defined as a dynamic nanosized, sterol- and sphingolipid-enriched ordered association of specific proteins, in which a metastable resting state can be activated by a combination of specific lipid-lipid, protein-lipid, and protein-protein interactions. There are more and more experimental data that confirm their participation in such live processes as endocytosis, apoptosis, internalization of toxins, bacteria, viruses, etc., as well as their important role in the protective mechanisms of the cell under different stressors. In this work, a fluorescent marker of sterols – filipin and a fluorescent probe laurdan were used to confirm the presence of cholesterol and sphingolipid-enriched lipid ranges in CM. Our results regarding the increase in generalized polarization in the clinorotation conditions correlate with the data obtained in previous studies and indicate the sensitivity of the CM to a longer action of the clinorotation.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.06.085
P. Kozak, Y.E. Zlochevskyi, L. Kozak, S. Stariy
We present the method for kinematic and photometric processing of results of single-station video observations of a unique bright fireball (bolide or space vehicle remnant) carried out in bad observational conditions. Due to the low sensitivity of the video camera, lots of star-shaped artifacts in the camera detector on the one hand, and the bright Moon of -10.95 mag, which was directly in the camera field of view on the other, the star images were completely absent in all the frames. It is demonstrated that using the averaging and summing algorithms applied to the whole set of frames and the display of different dynamic layers of intensity allowed us to find and identify 45 reference stars, the faintest of which were of 5.4…5.7 mag. Due to the visibility of the point of closest approach of the object trajectory to an observer, which corresponds to the maximum angular velocity, in the camera field of view and the performed modeling, we obtained the next data about the fireball from the single-station detection after the video processing. The fireball fall lasted longer than 12 seconds, the angular length of the trajectory exceeded 60 deg, maximum angular velocity was computed as 7.4 deg/sec. It was shown that the space body in the point of maximal approach could lose near 32 percent of its initial velocity. Visibility of the maximal approach point allowed us to calculate the right ascension and declination of the visible radiant as 272.0 and -0.8 deg, respectively. The luminosity of the fireball was varying in the range of -5.5 to -8.5 mag. All the calculations performed did not allow us to unambiguously identify the fireball as a meteoroid or as a cosmic debris fragment.
{"title":"Problems of videorecords processing of bright bolides and falling space vehicle remnants detected with the low-sensitive home video cameras in bad observational conditions","authors":"P. Kozak, Y.E. Zlochevskyi, L. Kozak, S. Stariy","doi":"10.15407/knit2021.06.085","DOIUrl":"https://doi.org/10.15407/knit2021.06.085","url":null,"abstract":"We present the method for kinematic and photometric processing of results of single-station video observations of a unique bright fireball (bolide or space vehicle remnant) carried out in bad observational conditions. Due to the low sensitivity of the video camera, lots of star-shaped artifacts in the camera detector on the one hand, and the bright Moon of -10.95 mag, which was directly in the camera field of view on the other, the star images were completely absent in all the frames. It is demonstrated that using the averaging and summing algorithms applied to the whole set of frames and the display of different dynamic layers of intensity allowed us to find and identify 45 reference stars, the faintest of which were of 5.4…5.7 mag. Due to the visibility of the point of closest approach of the object trajectory to an observer, which corresponds to the maximum angular velocity, in the camera field of view and the performed modeling, we obtained the next data about the fireball from the single-station detection after the video processing. The fireball fall lasted longer than 12 seconds, the angular length of the trajectory exceeded 60 deg, maximum angular velocity was computed as 7.4 deg/sec. It was shown that the space body in the point of maximal approach could lose near 32 percent of its initial velocity. Visibility of the maximal approach point allowed us to calculate the right ascension and declination of the visible radiant as 272.0 and -0.8 deg, respectively. The luminosity of the fireball was varying in the range of -5.5 to -8.5 mag. All the calculations performed did not allow us to unambiguously identify the fireball as a meteoroid or as a cosmic debris fragment.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.06.105
S.V. Adzhamskiy, G. Kononenko, R. Podolskyi
We consider the improvement is considered of the modes of selective laser melting technology based on the design model to reduce the level of residual stresses and prevent deviations in the geometry of the part. Simulation results are presented on a universal voxel structure and a simplified object to predict metal behavior depending on the specific energy density in the region of the boundaries of a metal part made of Inconel 718. An experiment was carried out to study the influence of different strategies and process modes on the curvature of parts as a result of the effect of residual stresses in order to minimize them. Printing was carried out on a 3-D printer "Alfa-150" (LLC "ALT Ukraine") at constant power (P, W) and distance between tracks (d, mm) in each zone (up-skin, down-skin, in - skin) with a change in the speed (V, mm / s) of the laser beam movement, as well as a different pattern of sample growth by 3-D printing with 67 degrees rotation of each new layer relative to the previous one. To identify defects and deviations from the original model to the solid (sample), metallographic analysis was performed using optical microscopy (Carl Zeiss AXIOVERT 200M). It was found that the simulation of printing processes, performed on the Magics platform by breaking the model into a voxel structure, allows an analytical assessment of stresses and strains. Analysis of the appearance of the prototypes showed that the best down-skin indicators are formed at a power of 80 W and a specific energy density (40 ... 38 J / mm3). By using the 67 degrees staggered printing strategy at the optimum specific energy density, it is possible to minimize the residual internal stresses leading to distortion of the product. In the future, the results can be supplemented by studies of the effect of residual stresses of compressive forces when exposed to a laser beam at constant applied power. Using a computational model that allows calculating the residual stresses during the deposition of the next layer, depending on the speed of the laser, the power and the distance between the applied tracks, it is possible to obtain high-precision parts with specified properties. The adaptation of the model, which allows us to obtain a quantitative estimate of the residual thermal stresses depending on the speed of movement and the laser power for the Inconel 718 heat-resistant alloy, has been carried out. Optimal modes have been determined to minimize these stresses and reduce the curvature of the part.
{"title":"Influence of SLM-process parameters on the formation of the boundaries of parts of heat-resistant nickel alloy Inconel 718","authors":"S.V. Adzhamskiy, G. Kononenko, R. Podolskyi","doi":"10.15407/knit2021.06.105","DOIUrl":"https://doi.org/10.15407/knit2021.06.105","url":null,"abstract":"We consider the improvement is considered of the modes of selective laser melting technology based on the design model to reduce the level of residual stresses and prevent deviations in the geometry of the part. Simulation results are presented on a universal voxel structure and a simplified object to predict metal behavior depending on the specific energy density in the region of the boundaries of a metal part made of Inconel 718. An experiment was carried out to study the influence of different strategies and process modes on the curvature of parts as a result of the effect of residual stresses in order to minimize them. Printing was carried out on a 3-D printer \"Alfa-150\" (LLC \"ALT Ukraine\") at constant power (P, W) and distance between tracks (d, mm) in each zone (up-skin, down-skin, in - skin) with a change in the speed (V, mm / s) of the laser beam movement, as well as a different pattern of sample growth by 3-D printing with 67 degrees rotation of each new layer relative to the previous one. To identify defects and deviations from the original model to the solid (sample), metallographic analysis was performed using optical microscopy (Carl Zeiss AXIOVERT 200M). It was found that the simulation of printing processes, performed on the Magics platform by breaking the model into a voxel structure, allows an analytical assessment of stresses and strains. Analysis of the appearance of the prototypes showed that the best down-skin indicators are formed at a power of 80 W and a specific energy density (40 ... 38 J / mm3). By using the 67 degrees staggered printing strategy at the optimum specific energy density, it is possible to minimize the residual internal stresses leading to distortion of the product. In the future, the results can be supplemented by studies of the effect of residual stresses of compressive forces when exposed to a laser beam at constant applied power. Using a computational model that allows calculating the residual stresses during the deposition of the next layer, depending on the speed of the laser, the power and the distance between the applied tracks, it is possible to obtain high-precision parts with specified properties. The adaptation of the model, which allows us to obtain a quantitative estimate of the residual thermal stresses depending on the speed of movement and the laser power for the Inconel 718 heat-resistant alloy, has been carried out. Optimal modes have been determined to minimize these stresses and reduce the curvature of the part.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67116970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.06.003
O. Pylypenko, O. O. Prokopchuk, S. Dolgopolov, O. Nikolayev, N. Khoriak, V.Yu. Pysarenko, I. D. Bashliy, S.V. Polskykh
Liquid-propellant rocket propulsion systems of the first stages of launch vehicles of medium, heavy, and super-heavy class usually include POGO-suppressors, which are one of the most widely used methods to eliminate launch vehicle longitudinal structural vibrations (POGO phenomena). However, until now, the theoretical studies and analysis of the effect of the POGO-suppressors’ installation in the feedlines of main liquid rocket engines on transient processes in systems during rocket engine starting have not been carried out due to the complexity of such analysis and the lack, first of all, reliable nonlinear models of cavitation phenomena in rocket engine pumps. A mathematical model for the start-up of a clustered rocket propulsion of the Cyclone-4M launch vehicle has been developed that takes into account the low-frequency dynamics of the POGO-suppressors and the asynchronous start-up timeline sequences of the rocket engines. The first stage of the launch vehicle propulsion system includes four RD-870 rocket engines. A nonlinear mathematical model of low-frequency dynamic processes of the POGO-suppressor with bellows separation of liquid and gaseous media is presented. A significant effect of cavitation in the pumps of engines and the POGO-suppressor installation to the LOX feedline on the propulsion system dynamic gains is shown. Based on the developed mathematical model of the clustered rocket propulsion start-up, the studies of the Cyclone-4M main engines’ start-up transients were carried out. The asynchronous start-up timeline sequences of the rocket engine and the places of installation of the POGO-suppressors in the LOX feedline branches to the RD-870 rocket engine – near the general feedline collector as standard placement or directly at the entrance to the engines – were investigated. The analysis of start-up transients in the oxidizer feed system of the considered propulsion (the time dependences of the flowrate and pressure at the engine inlet) showed the following. Firstly, while the synchronous start-up of the engines, the installation of the POGO-suppressors near the feedline collector makes it possible to eliminate all engine inlet overpressures that exist in the rocket propulsion system in case of the absence of the POGO-suppressors. Secondly, the RD-870 engine asynchronous start-up operation affects negatively the time dependences of the propellant flowrate and pressure at the engine inlet if the POGO-suppressors are located near the feedline collector. So, in the propulsion system’s start-up timeline interval 0.95 s - 1.35 s, for some computational variants of the initial moments of the engine operation start, an abnormally large drop in the LOX flow rate and the overpressures at the engine inlet is observed. The asynchronous start-up of the RD-870 engines with the installation of the POGO-suppressors at the engine inlet does not significantly change the start-up transients compared to the synchronous starting of the engines. Th
中型、重型和超重型运载火箭的一级液体推进剂推进系统中，通常都有POGO抑制装置，这是消除运载火箭纵向结构振动(POGO)现象最常用的方法之一。然而，由于分析的复杂性和缺乏可靠的火箭发动机泵内空化现象的非线性模型，迄今为止，主要液体火箭发动机进给线中安装pogo抑制器对火箭发动机启动过程中系统瞬态过程影响的理论研究和分析尚未开展。建立了旋风- 4m运载火箭集束火箭推进启动数学模型，该模型考虑了pogo抑制器的低频动力学特性和火箭发动机的异步启动时间轴序列。运载火箭推进系统的第一级包括四个RD-870火箭发动机。建立了波纹管分离液、气介质pogo抑制器低频动态过程的非线性数学模型。结果表明，发动机泵的空化和液氧馈线上的pogo抑制装置对推进系统动态增益有显著影响。基于建立的集束火箭推进启动数学模型，对旋风- 4m型主发动机启动瞬态进行了研究。研究了火箭发动机的异步启动时间序列和在RD-870火箭发动机的液氧馈线分支中安装pogo抑制器的位置——靠近一般馈线收集器作为标准位置或直接在发动机入口处。对考虑推进的氧化剂进料系统启动瞬态的分析(发动机入口流量和压力的时间依赖性)显示如下。首先，当发动机同步启动时，在馈线收集器附近安装pogo抑制器可以消除在没有pogo抑制器的情况下存在于火箭推进系统中的所有发动机进口超压。其次，RD-870发动机异步启动操作对发动机进气道推进剂流量和压力的时间依赖性产生负面影响，如果pogo抑制器位于馈线收集器附近。因此，在推进系统启动时间间隔0.95 s - 1.35 s内，对于发动机启动初始时刻的一些计算变量，可以观察到发动机进气道液氧流量和超压的异常大的下降。与发动机同步启动相比，在发动机进气道安装pogo抑制器的RD-870发动机的异步启动不会显著改变启动瞬态。第三，结果表明，在发动机进气道和RD-870分支靠近收集器处安装pogo抑制器对旋风- 4m运载火箭一级主发动机启动瞬态过程的质量有显著的积极影响。将pogo抑制器放置在发动机进气道不是标准的，并且在考虑时没有参考推进系统的布局。然而，安装在发动机入口的pogo抑制器是防止液体火箭发动机参数超调和下降的有效手段，包括在集群推进系统中液体火箭发动机的异步启动条件。所得结果可用于与助推火箭并联使用的多级支撑火箭或包含pogo抑制器的集束式多发动机火箭推进系统的一级推进系统启动的数学建模。
{"title":"Mathematical modelling of start-up transients at clustered propulsion system with POGO-suppressors for CYCLON-4M launch vehicle","authors":"O. Pylypenko, O. O. Prokopchuk, S. Dolgopolov, O. Nikolayev, N. Khoriak, V.Yu. Pysarenko, I. D. Bashliy, S.V. Polskykh","doi":"10.15407/knit2021.06.003","DOIUrl":"https://doi.org/10.15407/knit2021.06.003","url":null,"abstract":"Liquid-propellant rocket propulsion systems of the first stages of launch vehicles of medium, heavy, and super-heavy class usually include POGO-suppressors, which are one of the most widely used methods to eliminate launch vehicle longitudinal structural vibrations (POGO phenomena). However, until now, the theoretical studies and analysis of the effect of the POGO-suppressors’ installation in the feedlines of main liquid rocket engines on transient processes in systems during rocket engine starting have not been carried out due to the complexity of such analysis and the lack, first of all, reliable nonlinear models of cavitation phenomena in rocket engine pumps. A mathematical model for the start-up of a clustered rocket propulsion of the Cyclone-4M launch vehicle has been developed that takes into account the low-frequency dynamics of the POGO-suppressors and the asynchronous start-up timeline sequences of the rocket engines. The first stage of the launch vehicle propulsion system includes four RD-870 rocket engines. A nonlinear mathematical model of low-frequency dynamic processes of the POGO-suppressor with bellows separation of liquid and gaseous media is presented. A significant effect of cavitation in the pumps of engines and the POGO-suppressor installation to the LOX feedline on the propulsion system dynamic gains is shown. Based on the developed mathematical model of the clustered rocket propulsion start-up, the studies of the Cyclone-4M main engines’ start-up transients were carried out. The asynchronous start-up timeline sequences of the rocket engine and the places of installation of the POGO-suppressors in the LOX feedline branches to the RD-870 rocket engine – near the general feedline collector as standard placement or directly at the entrance to the engines – were investigated. The analysis of start-up transients in the oxidizer feed system of the considered propulsion (the time dependences of the flowrate and pressure at the engine inlet) showed the following. Firstly, while the synchronous start-up of the engines, the installation of the POGO-suppressors near the feedline collector makes it possible to eliminate all engine inlet overpressures that exist in the rocket propulsion system in case of the absence of the POGO-suppressors. Secondly, the RD-870 engine asynchronous start-up operation affects negatively the time dependences of the propellant flowrate and pressure at the engine inlet if the POGO-suppressors are located near the feedline collector. So, in the propulsion system’s start-up timeline interval 0.95 s - 1.35 s, for some computational variants of the initial moments of the engine operation start, an abnormally large drop in the LOX flow rate and the overpressures at the engine inlet is observed. The asynchronous start-up of the RD-870 engines with the installation of the POGO-suppressors at the engine inlet does not significantly change the start-up transients compared to the synchronous starting of the engines. Th","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.06.053
V. Vlasenko, V. M. Mamarev, V. Ozhynsky, O. Ulyanov, V. Zakharenko, M. Palamar, A. Chaikovskyi, S. Fryz
On March 15th, 2021, scientists of the National Space Facilities Control and Tests Center and the Radio Astronomical Institute of the National Academy of Sciences of Ukraine carried out preliminary observations with the Ukrainian new generation radio telescope RT-32 (Zolochiv, Lviv region). The extragalactic radiation of radio galaxy 3C84 (Perseus-A), masers from the galactic molecular cloud W3, radio emission of methanol maser from the galactic radio source G188.946 + 0.886 were observed and successfully recorded. Observations were performed as training in the framework of preparation for the launch of a joint Ukrainian-Latvian radio astronomy project lzp-2020/2-0121. The results of the observations confirmed the world level of RT-32 radio telescope characteristics, the efficiency of the primary error matrix and revealed several shortcomings in the functioning of the tracking system. It was found that the primary tracking error matrix has insufficient discreteness and contains errors of the first and second types. In the article, we present a method of automatic construction of the radio telescope error matrix according to the data of a radiometric receiver and receivers-recorders. The method of construction provides automatic processing of the obtained radiometric data. The results of verification of the developed method using the reference radio sources of different types and the elements of tracking errors’ matrix by the elevation and azimuth obtained when using it are presented. The results obtained with the proposed method were included in the radio telescope control system and allowed us to increase the aiming accuracy of the RT-32 radio telescope.
{"title":"The method for RT-32 radio telescope error matrix construction in automatic mode. Automatic assesment of tracking errors","authors":"V. Vlasenko, V. M. Mamarev, V. Ozhynsky, O. Ulyanov, V. Zakharenko, M. Palamar, A. Chaikovskyi, S. Fryz","doi":"10.15407/knit2021.06.053","DOIUrl":"https://doi.org/10.15407/knit2021.06.053","url":null,"abstract":"On March 15th, 2021, scientists of the National Space Facilities Control and Tests Center and the Radio Astronomical Institute of the National Academy of Sciences of Ukraine carried out preliminary observations with the Ukrainian new generation radio telescope RT-32 (Zolochiv, Lviv region). The extragalactic radiation of radio galaxy 3C84 (Perseus-A), masers from the galactic molecular cloud W3, radio emission of methanol maser from the galactic radio source G188.946 + 0.886 were observed and successfully recorded. Observations were performed as training in the framework of preparation for the launch of a joint Ukrainian-Latvian radio astronomy project lzp-2020/2-0121. The results of the observations confirmed the world level of RT-32 radio telescope characteristics, the efficiency of the primary error matrix and revealed several shortcomings in the functioning of the tracking system. It was found that the primary tracking error matrix has insufficient discreteness and contains errors of the first and second types. In the article, we present a method of automatic construction of the radio telescope error matrix according to the data of a radiometric receiver and receivers-recorders. The method of construction provides automatic processing of the obtained radiometric data. The results of verification of the developed method using the reference radio sources of different types and the elements of tracking errors’ matrix by the elevation and azimuth obtained when using it are presented. The results obtained with the proposed method were included in the radio telescope control system and allowed us to increase the aiming accuracy of the RT-32 radio telescope.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.06.016
N. Baranets, Y. Ruzhin, J. Vojta
We present the results of the active space experiment with charged particle beam's injection (electrons and xenon ions) carried out onboard Intercosmos-25 station and daughter Magion-3 subsatellite. The ones are obtained under conditions when the particle beams were injected in opposite directions relative to the magnetic field B0 in such a way that the electron injection was directed towards the Earth. Mechanisms of beam-plasma instabilities relative to the excitation of electrostatic and electromagnetic waves are considered during the electron beam injection (~10 keV, 0.1 A) from the Intercosmos-25 station. Development of transverse instability on the first cyclotron resonance leads to the excitation of whistler mode waves backward-propagating relative to the injected electrons (from the Earth). The investigation object was the beam-excited differential fluxes of ionospheric electrons in a wide energetic range of 27 eV — 412 keV registered by the charged particle spectrometers onboard the Magion-3 subsatellite. Thereby, the interaction of whistler waves with ionospheric electron fluxes is stimulated by the energy transfer mechanisms such as 'particle-wave-particle'. Numerical results of beam-plasma instabilities are compared also with thermal plasma parameters registered at different space points on the station and subsatellite. Excitation of longitudinal and transverse beam-plasma instabilities will inevitably lead to their competition, which will affect the results of the experiment. The data of stimulated fluxes of ionospheric electrons allow us to investigate the various effects of the wave-particle interaction, taking into account the influence of the growth rate of longitudinal instability on the excitation angle of whistlers and their structure. This approach is based on the results of laboratory experiments to determine the pattern of excited whistlers for an electric dipole antenna and the analogy of the beam-plasma channel with the radiating system. The results of the active space experiment confirm the dependence of the growth rate of whistler mode waves on the development of longitudinal beam instability.
本文介绍了在Intercosmos-25空间站和其子卫星Magion-3上进行的带电粒子束注入(电子和氙离子)主动空间实验的结果。当粒子束以相对于磁场B0的相反方向注入时，电子注入是指向地球的，在这种情况下获得的。研究了来自Intercosmos-25站的电子束注入(~10 keV, 0.1 A)过程中相对于静电和电磁波激发的束等离子体不稳定性机制。第一回旋共振上横向不稳定性的发展导致了相对于注入电子(来自地球)反向传播的哨声模式波的激发。研究对象是由星载带电粒子谱仪记录的27 eV - 412 keV宽能量范围内电离层电子的束激微分通量。因此，哨声波与电离层电子通量的相互作用受到“粒子-波-粒子”等能量传递机制的刺激。并将束等离子体不稳定性的数值结果与站内和星下不同空间点记录的热等离子体参数进行了比较。纵向和横向光束等离子体不稳定性的激发将不可避免地导致它们之间的竞争，从而影响实验结果。电离层电子受激通量的数据使我们能够研究波粒相互作用的各种效应，同时考虑到纵向不稳定性的增长速度对哨子激发角及其结构的影响。这种方法是基于实验室实验的结果来确定电偶极子天线的激发哨声模式，并将光束-等离子体通道与辐射系统进行类比。主动空间实验结果证实了哨声模波的增长速度与纵梁失稳发展的相关性。
{"title":"Wave-particle interaction during electron beam-modulated injection into the ionospheric plasma. Theory and experiment","authors":"N. Baranets, Y. Ruzhin, J. Vojta","doi":"10.15407/knit2021.06.016","DOIUrl":"https://doi.org/10.15407/knit2021.06.016","url":null,"abstract":"We present the results of the active space experiment with charged particle beam's injection (electrons and xenon ions) carried out onboard Intercosmos-25 station and daughter Magion-3 subsatellite. The ones are obtained under conditions when the particle beams were injected in opposite directions relative to the magnetic field B0 in such a way that the electron injection was directed towards the Earth. Mechanisms of beam-plasma instabilities relative to the excitation of electrostatic and electromagnetic waves are considered during the electron beam injection (~10 keV, 0.1 A) from the Intercosmos-25 station. Development of transverse instability on the first cyclotron resonance leads to the excitation of whistler mode waves backward-propagating relative to the injected electrons (from the Earth). The investigation object was the beam-excited differential fluxes of ionospheric electrons in a wide energetic range of 27 eV — 412 keV registered by the charged particle spectrometers onboard the Magion-3 subsatellite. Thereby, the interaction of whistler waves with ionospheric electron fluxes is stimulated by the energy transfer mechanisms such as 'particle-wave-particle'. Numerical results of beam-plasma instabilities are compared also with thermal plasma parameters registered at different space points on the station and subsatellite. Excitation of longitudinal and transverse beam-plasma instabilities will inevitably lead to their competition, which will affect the results of the experiment. The data of stimulated fluxes of ionospheric electrons allow us to investigate the various effects of the wave-particle interaction, taking into account the influence of the growth rate of longitudinal instability on the excitation angle of whistlers and their structure. This approach is based on the results of laboratory experiments to determine the pattern of excited whistlers for an electric dipole antenna and the analogy of the beam-plasma channel with the radiating system. The results of the active space experiment confirm the dependence of the growth rate of whistler mode waves on the development of longitudinal beam instability.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.06.038
S. Khoroshylov, M. Redka
The advances in deep learning have revolutionized the field of artificial intelligence, demonstrating the ability to create autonomous systems with a high level of understanding of the environments where they operate. These advances, as well as new tasks and requirements in space exploration, have led to an increased interest in these deep learning methods among space scientists and practitioners. The goal of this review article is to analyze the latest advances in deep learning for navigation, guidance, and control problems in space. The problems of controlling the attitude and relative motion of spacecraft are considered for both traditional and new missions, such as orbital service. The results obtained using these methods for landing and hovering operations considering missions to the Moon, Mars, and asteroids are also analyzed. Both supervised and reinforcement learning are used to solve such problems based on various architectures of artificial neural networks, including convolutional and recurrent ones. The possibility of using deep learning together with methods of control theory is analyzed to solve the considered problems more efficiently. The difficulties that limit the application of the reviewed methods for space applications are highlighted. The necessary research directions for solving these problems are indicated.
{"title":"Deep learning for spacecraft guidance, navigation, and control","authors":"S. Khoroshylov, M. Redka","doi":"10.15407/knit2021.06.038","DOIUrl":"https://doi.org/10.15407/knit2021.06.038","url":null,"abstract":"The advances in deep learning have revolutionized the field of artificial intelligence, demonstrating the ability to create autonomous systems with a high level of understanding of the environments where they operate. These advances, as well as new tasks and requirements in space exploration, have led to an increased interest in these deep learning methods among space scientists and practitioners. The goal of this review article is to analyze the latest advances in deep learning for navigation, guidance, and control problems in space. The problems of controlling the attitude and relative motion of spacecraft are considered for both traditional and new missions, such as orbital service. The results obtained using these methods for landing and hovering operations considering missions to the Moon, Mars, and asteroids are also analyzed. Both supervised and reinforcement learning are used to solve such problems based on various architectures of artificial neural networks, including convolutional and recurrent ones. The possibility of using deep learning together with methods of control theory is analyzed to solve the considered problems more efficiently. The difficulties that limit the application of the reviewed methods for space applications are highlighted. The necessary research directions for solving these problems are indicated.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.06.098
E. Dzhur, N. Kalinina, O.E. Dzhur, A. Kalinin, T. Nosova, S. Mamchur
The objective of the work is to obtain a dispersed structure and increase the mechanical and technological properties of deformed aluminum alloys by treating melts with nanodispersed modifiers. The effect of the modification by refractory nanodispersed compositions of titanium carbonitride and silicon carbide on the grain structure and properties of aluminum alloys has been established. Aluminum alloys of the Al-Mg, Al-Mg-Sc system have been studied. The scientific novelty of the work lies in the establishment of the mechanism of influence of the nanodispersed modifier on the grain structure and the set of properties of aluminum alloys. The composition of the modifier is proposed — nanodispersed powders of silicon carbide (SiC) and titanium carbonitride (TiCN) with fractions of 50 ... 100 nm. The microstructure of alloys was studied under optical microscopes. The strength properties of the alloys were determined on a TIRAtest300 machine. Fluidity was determined using the spiral test method. In the modified samples of aluminum alloys, improved technological properties were achieved. It was found that, in alloys AMg5 and 1545, the fluidity increased by an average of 10 %. After the modification, we obtained a homogeneous dispersed structure of aluminum alloys. It turned out that the average grain size in the modified samples of alloy 1545 decreased 1.6 times in comparison with the initial state due to the increase of strength characteristics by 14… 20 %. A series of experimental-industrial melting of AMg5 and 1545 alloys has been carried out. The effective influence of a refractory modifier based on silicon carbide and titanium carbonitride on the properties of aluminum alloys has been proved. The results of the work are of practical importance for aviation and space technology products.
{"title":"Promotion of properties of deformed aluminium alloys in modification with nanocomposites","authors":"E. Dzhur, N. Kalinina, O.E. Dzhur, A. Kalinin, T. Nosova, S. Mamchur","doi":"10.15407/knit2021.06.098","DOIUrl":"https://doi.org/10.15407/knit2021.06.098","url":null,"abstract":"The objective of the work is to obtain a dispersed structure and increase the mechanical and technological properties of deformed aluminum alloys by treating melts with nanodispersed modifiers. The effect of the modification by refractory nanodispersed compositions of titanium carbonitride and silicon carbide on the grain structure and properties of aluminum alloys has been established. Aluminum alloys of the Al-Mg, Al-Mg-Sc system have been studied. The scientific novelty of the work lies in the establishment of the mechanism of influence of the nanodispersed modifier on the grain structure and the set of properties of aluminum alloys. The composition of the modifier is proposed — nanodispersed powders of silicon carbide (SiC) and titanium carbonitride (TiCN) with fractions of 50 ... 100 nm. The microstructure of alloys was studied under optical microscopes. The strength properties of the alloys were determined on a TIRAtest300 machine. Fluidity was determined using the spiral test method. In the modified samples of aluminum alloys, improved technological properties were achieved. It was found that, in alloys AMg5 and 1545, the fluidity increased by an average of 10 %. After the modification, we obtained a homogeneous dispersed structure of aluminum alloys. It turned out that the average grain size in the modified samples of alloy 1545 decreased 1.6 times in comparison with the initial state due to the increase of strength characteristics by 14… 20 %. A series of experimental-industrial melting of AMg5 and 1545 alloys has been carried out. The effective influence of a refractory modifier based on silicon carbide and titanium carbonitride on the properties of aluminum alloys has been proved. The results of the work are of practical importance for aviation and space technology products.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67117434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15407/knit2021.04.065
N. Japashov, A. Mansurova, N. Balta, Almaty Kazakhstan Biology, A. Mathematics
Plants are essential types of human nutrition, both in terrestrial and in space station conditions. The cultivation of plant foods in space conditions at the near-Earth stations has become possible due to the modern achievements in agricultural technologies. The proposed article aims to study the creation of optimal conditions for growing plants used in human nutrition in the space stations. In the work, a selection of plants and soil types for space station conditions was made. For this purpose, a three-stage experiment was carried out. In the first experiment, an experimental method was exploited to select the types of plants that are most suitable for growing under extreme conditions. The composition and structure of the soil were determined experimentally. It is shown that hydrogel can be used to accumulate water in space station conditions and can be a suitable medium for growing plants. Studies have shown that just hydrogel (without any nutrient mixtures) can promote plant growth. At the second stage of research, plants were successfully grown on the mixture of the hydrogel and the soil. In the third experiment, the authors added biostimulants and organic products to the hydrogel, and as a result, there was an increase in the speed and stability of plant growth. The experimental prototype of the container for growing plants in space conditions, which was tested in the above experiments, created by the authors, is shown.
{"title":"Creating a microgreen growing environment at the space station","authors":"N. Japashov, A. Mansurova, N. Balta, Almaty Kazakhstan Biology, A. Mathematics","doi":"10.15407/knit2021.04.065","DOIUrl":"https://doi.org/10.15407/knit2021.04.065","url":null,"abstract":"Plants are essential types of human nutrition, both in terrestrial and in space station conditions. The cultivation of plant foods in space conditions at the near-Earth stations has become possible due to the modern achievements in agricultural technologies. The proposed article aims to study the creation of optimal conditions for growing plants used in human nutrition in the space stations. In the work, a selection of plants and soil types for space station conditions was made. For this purpose, a three-stage experiment was carried out. In the first experiment, an experimental method was exploited to select the types of plants that are most suitable for growing under extreme conditions. The composition and structure of the soil were determined experimentally. It is shown that hydrogel can be used to accumulate water in space station conditions and can be a suitable medium for growing plants. Studies have shown that just hydrogel (without any nutrient mixtures) can promote plant growth. At the second stage of research, plants were successfully grown on the mixture of the hydrogel and the soil. In the third experiment, the authors added biostimulants and organic products to the hydrogel, and as a result, there was an increase in the speed and stability of plant growth. The experimental prototype of the container for growing plants in space conditions, which was tested in the above experiments, created by the authors, is shown.","PeriodicalId":42936,"journal":{"name":"Space Science and Technology-Kosmicna Nauka i Tehnologia","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67116499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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