Space Activities Research Articles

Experimental study of ion beam interaction with target surface aimed at developing a contactless method for space debris removal by an ion beam

Research and development in the field of space debris (SD) removal technologies is one of the most important and urgent tasks facing all spacefaring nations. By now, a large number of different concepts of removal have already been proposed. One of them is the SD removal by ion beam generated by an ion source installed on board a service spacecraft (SSC). A detailed understanding of the process of ion beam interaction with the SD surface is required to develop an optimal control algorithm for the virtual SSC-SD mated configuration in order to improve this method of SD removal. In addition, when designing the SSC, it is necessary to take into account back flows of the material sputtered from the surface of removed SD by the ion beam, which can contaminate the SSC operating surfaces during the removal maneuver. Within the framework of the presented work, experimental studies were performed to determine the coefficient of accommodation of the ion impulse during the ion beam interaction with the surface of the target simulating the external surface of the removed object. Besides, the flow density of the sputtered target material was experimentally evaluated during its exposure to the ion beam. To do this, we used the radio-frequency ion source (injector) with a beam diameter of 160 mm, which is supposed to be used as an actuating unit on board the SSC designed for transporting the SD objects to the disposal orbit or to the orbits with limited life. When measuring the ion beam accommodation coefficient, the presence of additional force arising on the target due to the flow of sputtered material leaving its surface, and the ion-electron emission process on the target, which could distort the experimental data, were taken into account. To estimate the magnitude of the flows of sputtered target material under the influence of the ion beam, a special experimental design was developed for simulating the presence of a point source of sputtered material. The results obtained in this work will be used for modeling the impact of the ion beam on the surface of real SD objects with complex geometry using the finite element method, for refining the control algorithm of the virtual SSC-SDO mated configuration and for developing proposals on the SSC layout, which should reduce or completely eliminate the negative impact associated with the material sputtering from the SDO surface onto the SSC elements. Successful implementation of the developed method of SDO removal will contribute to improving the safety of space activities for all countries and to the development of the rocket-and-space industry in the Russian Federation, in particular.

Structure of the ISW1a complex bound to the dinucleosome.

Nucleosomes are basic repeating units of chromatin and form regularly spaced arrays in cells. Chromatin remodelers alter the positions of nucleosomes and are vital in regulating chromatin organization and gene expression. Here we report the cryo-EM structure of chromatin remodeler ISW1a complex from Saccharomyces cerevisiae bound to the dinucleosome. Each subunit of the complex recognizes a different nucleosome. The motor subunit binds to the mobile nucleosome and recognizes the acidic patch through two arginine residues, while the DNA-binding module interacts with the entry DNA at the nucleosome edge. This nucleosome-binding mode provides the structural basis for linker DNA sensing of the motor. Notably, the Ioc3 subunit recognizes the disk face of the adjacent nucleosome through interacting with the H4 tail, the acidic patch and the nucleosomal DNA, which plays a role in the spacing activity in vitro and in nucleosome organization and cell fitness in vivo. Together, these findings support the nucleosome spacing activity of ISW1a and add a new mode of nucleosome remodeling in the context of a chromatin environment.

Asset-Based Financing For Space Activities

The space industry—whose numbers are already substantial—has undeniable potential for further growth. However, because it no longer consists of only multibillion-dollar companies, the industry needs access to traditional financing. Venture capital alone is insufficient. This Article discusses some difficulties for the space industry’s access to traditional—and especially asset-based—financing. Some are common to all space activities, while some exist only for novel space activities. These difficulties cover a broad range of legal, regulatory, and factual issues (including insurance). While the problems are difficult, ideas to solve them are plentiful, a number of which the paper discusses. The paper also presents ways in which the industry can do much to advance its own interests. In addition, actions by governments, both at the domestic and the international level, are recommended.

Controlling active turbulence by activity patterns.

By patterning activity in space, one can control active turbulence. To show this, we use Doi's hydrodynamic equations of a semidilute solution of active rods. A linear stability analysis reveals the resting isotropic fluid to be unstable above an absolute pusher activity. The emergent activity-induced paranematic state displays active turbulence, which we characterize by different quantities including the energy spectrum, which shows the typical power-law decay with exponent -4. Then, we control the active turbulence by a square lattice of circular spots where activity is switched off. In the parameter space lattice constant versus surface-to-surface distance of the spots, we identify different flow states. Most interestingly, for lattice constants below the vorticity correlation length and for spot distances smaller than the nematic coherence length, we observe a multi-lane flow state, where flow lanes with alternating flow directions are separated by a street of vortices. The flow pattern displays pronounced multistability and also appears transiently at the transition to the isotropic active-turbulence state. At larger lattice constants a trapped vortex state is identified with a non-Gaussian vorticity distribution due to the low flow vorticity at the spots. It transitions to conventional active turbulence for increasing spot distance.

Space Mining

The Outer Space Treaty, the leading source of law for activities in space, has laid out various limitations and regulations regarding actions in space and how space can be used. One of these limitations is commonly referred to as the “non-appropriation principle.” The non-appropriation principle prohibits nations from making claims of sovereignty over celestial bodies in space. This presents a problem as the space industry continues to progress because it causes uncertainty regarding the meaning of appropriation, what is classified as a celestial body, what acts are allowed, and who specifically is prohibited from acting. This Comment identifies these problems and their potential solutions, specifically with the proposition of space mining in mind.

«Ядро-периферия» и периферийность в региональной науке

The article presents an analytical review of the development of the core-periphery and peripherality concepts in economic theory. The stages of formation of the core-periphery approach are marked by the contributions of the school of Latin American structuralism, theories of polarized development, dependency theory and world-system theory associated with the names of R. Prebisch, J. Friedmann, F. Perroux, S. Furtado, I. Wallerstein. The core-periphery concept has proved to be a useful analytical tool in studies of international trade and economic growth in the world economy. At the same time, uneven structures of distribution of economic activity in space, similar to the core-periphery structure, appear in many models of regional economy, starting with the model of agricultural production location by I. Thunen and ending with the core-periphery model by P. Krugman. These structures emerge without the help of the core-periphery concept, but as a result of the interaction of two fundamental factors – transport costs and economies of scale – and represent various combinations of dispersion and agglomeration. With regional inequality growing worldwide, the combination of the core-periphery approach and basic concepts of regional economics allows us to analyze the complex mechanisms of spatial polarization of economic space. Over time, the periphery has gone beyond the core-periphery dichotomy and developed into an independent category defined, defined by a combination of low accessibility of large markets, low population density and remoteness from decision-making centers. The concept of peripherality allows us to understand the processes of peripheralisation of previously prosperous territories through the interaction of power asymmetry and agglomeration effects

Effects of weightlessness on the cardiovascular system: a systematic review and meta-analysis.

Background: The microgravity environment has a direct impact on the cardiovascular system due to the fluid shift and weightlessness that results in cardiac dysfunction, vascular remodeling, and altered Cardiovascular autonomic modulation (CAM), deconditioning and poor performance on space activities, ultimately endangering the health of astronauts. Objective: This study aimed to identify the acute and chronic effects of microgravity and Earth analogues on cardiovascular anatomy and function and CAM. Methods: CINAHL, Cochrane Library, Scopus, Science Direct, PubMed, and Web of Science databases were searched. Outcomes were grouped into cardiovascular anatomic, functional, and autonomic alterations, and vascular remodeling. Studies were categorized as Spaceflight (SF), Chronic Simulation (CS), or Acute Simulation (AS) based on the weightlessness conditions. Meta-analysis was performed for the most frequent outcomes. Weightlessness and control groups were compared. Results: 62 articles were included with a total of 963 participants involved. The meta-analysis showed that heart rate increased in SF [Mean difference (MD) = 3.44; p = 0.01] and in CS (MD = 4.98; p < 0.0001), whereas cardiac output and stroke volume decreased in CS (MD = -0.49; p = 0.03; and MD = -12.95; p < 0.0001, respectively), and systolic arterial pressure decreased in AS (MD = -5.20; p = 0.03). According to the qualitative synthesis, jugular vein cross-sectional area (CSA) and volume were greater in all conditions, and SF had increased carotid artery CSA. Heart rate variability and baroreflex sensitivity, in general, decreased in SF and CS, whereas both increased in AS. Conclusion: This review indicates that weightlessness impairs the health of astronauts during and after spaceflight, similarly to the effects of aging and immobility, potentially increasing the risk of cardiovascular diseases. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42020215515.

Wojna i konflikt w cyberprzestrzeni. Piąty teatr wojny

The aim of this article is to present the genesis and typology of cyberspace and the threats that result from activities carried out in this area by state and non-state entities. The basic concepts, especially cyberspace, which is treated as a potential new theater of war, have been systematized. It was also presented the characteristics of the studied phenomenon from the point of view of using it to carry out destructive activities in the digital space and in the real world. Cyberspace is becoming an area for carrying out effective activities that serve to neutralize the enemy in a short time and with little effort. To prove his theses, the author uses numerous examples from the actual international relations, such as: the cyberwarfare in Estonia, the Israeli-American operations against Iranian ICT systems and the cyber-clashes between the United States of America and China.

Kultura off-roadu w perspektywie funkcjonowania hybrydalnego

Life in the modern world has shifted to some extent in the functioning of individuals in many areas. This paper focuses mainly on such spheres as communication, tracking and sharing information, and sport-related cultures, which take on a new meaning in the hybrid reality. These fields combine to create and enable a new type of human interaction. Reporting, commenting, or posting information on sports achievements is not a novelty, but currently this state of affairs is significantly gaining in importance and expanding to tracking information about the private life and functioning of people practicing various sports disciplines. Cultures that have developed around various physical activities are much more able to expand and promote a particular sport by publishing information in the digital space. It is particularly important in relation to disciplines that are not popular or are extreme or high-budget sports. Thanks to the presence of these activities in the virtual space, it is possible to promote, disseminate them, and gain a larger group of enthusiasts.

Fighting against violations of the right to privacy in the virtual space: ensuring the security of personal data

In the article, the legal regulations on the fight against violations of the right to privacy in the virtual space and ensuring the security of personal data were studied. The formation of the global information society, the transformation of the Internet into an integral part of social life was observed with the increase of people’s activity in the virtual space. On the one hand, it is characterized by positive aspects. Because in the virtual space, any person can easily meet the needs of daily life by using the opportunities provided as a user. For example, online shopping, online communication, searching for desired information in virtual space, etc. But on the other hand, the borderless nature of the virtual space, the use of anonymity (for example, through a fake profile) makes it difficult to detect and prevent violations committed in this space. In general, this raises the issue of protecting human rights and freedoms in the digital age, and among these rights and freedoms, the right to privacy has a special weight. Because people who use the virtual space provide their personal information to various platforms, or during communication, their personal life information remains in the virtual space, so that such information can later be used by criminals for illegal purposes. Therefore, protecting the security, confidentiality and completeness of information about personal and family life in the modern era is one of the most important tasks facing the world community. The author provided information about the most common types of violations of the right to personal integrity in the virtual space, and presented his suggestions on measures to combat them. In addition, the article analyzes the differences between the Anglo-Saxon and the European practice of personal data protection and draws conclusions about more successful practices.

Data-driven modelling of brain activity using neural networks, diffusion maps, and the Koopman operator.

We propose a machine-learning approach to construct reduced-order models (ROMs) to predict the long-term out-of-sample dynamics of brain activity (and in general, high-dimensional time series), focusing mainly on task-dependent high-dimensional fMRI time series. Our approach is a three stage one. First, we exploit manifold learning and, in particular, diffusion maps (DMs) to discover a set of variables that parametrize the latent space on which the emergent high-dimensional fMRI time series evolve. Then, we construct ROMs on the embedded manifold via two techniques: Feedforward Neural Networks (FNNs) and the Koopman operator. Finally, for predicting the out-of-sample long-term dynamics of brain activity in the ambient fMRI space, we solve the pre-image problem, i.e., the construction of a map from the low-dimensional manifold to the original high-dimensional (ambient) space by coupling DMs with Geometric Harmonics (GH) when using FNNs and the Koopman modes per se. For our illustrations, we have assessed the performance of the two proposed schemes using two benchmark fMRI time series: (i) a simplistic five-dimensional model of stochastic discrete-time equations used just for a "transparent" illustration of the approach, thus knowing a priori what one expects to get, and (ii) a real fMRI dataset with recordings during a visuomotor task. We show that the proposed Koopman operator approach provides, for any practical purposes, equivalent results to the FNN-GH approach, thus bypassing the need to train a non-linear map and to use GH to extrapolate predictions in the ambient space; one can use instead the low-frequency truncation of the DMs function space of L2-integrable functions to predict the entire list of coordinate functions in the ambient space and to solve the pre-image problem.

Relationship between imaginary space and ritual activities in the traditional village of Tenganan Pegringsingan, Bali, Indonesia

Relationship between imaginary space and ritual activities in the traditional village of Tenganan Pegringsingan, Bali, Indonesia

Relationship between imaginary space and ritual activities in the traditional village of Tenganan Pegringsingan, Bali, Indonesia

Relationship between imaginary space and ritual activities in the traditional village of Tenganan Pegringsingan, Bali, Indonesia

Analysis of Factors Affecting Space Teleoperation Safety Performance Based on a Hybrid Fuzzy DEMATEL Method

Teleoperation is one of the highest-risk activities in manned space activities. An appropriate set of influencing factors is essential for the safety assessment of teleoperation. The examination of the impact of a single factor or two factors on space teleoperation as done in the existing works suffers from the lack of a systematic analysis of factors. To address this gap, a hybrid α-level set incorporated in the hesitant fuzzy decision making trial and evaluation laboratory (DEMATEL) method was adopted in this study to identify and analyze teleoperation factors. The findings are as follows: (a) A system of influencing factors for teleoperation safety performance was constructed based on an extensive literature review and using the Delphi method with the aid of 30 space experts. The system covered 16 factors grouped based on individual, crew, machine, and context perspectives. (b) The α level affects the screening results of the pivotal influencing factors. For the average α level, five pivotal influencing factors, namely, team communication, basic cognitive ability, display interface information, control mode design, and task complexity, are identified from the 16 influencing factors. The present study represents a valuable effort in extracting the crucial influencing factors that affect teleoperation safety performance. It provides valuable insights from an ergonomic viewpoint and aids in determining priorities for enhancing operational safety.

Five-Meter Nonmagnetic Telescopic Tubular Mast: Design, Test, and On-Orbit Application

Space deployable masts, as one of the most widely used branches of space deployable structures, can provide driving, positioning, and transmission functions for spacecraft in orbit, which are irreplaceable in complex space activities. The nonmagnetic telescopic tubular mast (NMTTM) is designed and manufactured by the Shenyang Institute of Automation, Chinese Academy of Sciences, aboard the SATech-01 satellite to keep the magnetic probe assembly away from magnetic interference and realize global magnetic field measurement. The NMTTM can withstand complicated vibration and shock during rocket launching in the retracted state of 0.95 m, while it can be stably released and deployed to 5.28 m in orbit. NMTTM was successfully launched into Sun-synchronous orbit on 27 July 2022, fully deployed, and generated the positioning signal after a duration of 19 min and 16 s for the deployment process on 7 November. This paper focuses on the whole process of NMTTM from mission requirements to structure design and manufacture, through to releasing, deployment, and locking technology, environmental simulation tests, up to on-orbit deployment verification, which provides valuable experience for the subsequent development and application of large-scale space deployable masts.

The Architecture of Authority in Global Space Governance: The Moon Agreement as a Deconflicting Mechanism of Space Activities

The Architecture of Authority in Global Space Governance: The Moon Agreement as a Deconflicting Mechanism of Space Activities

The Nuances of Responsibility of Artificial Intelligence for Irresponsible Space Activity

The Nuances of Responsibility of Artificial Intelligence for Irresponsible Space Activity

The green path to space sustainability: Twenty years of research

The outer space environment is in a critical circumstance. This can cause severe impact on humanity. The main issue is an increasing space debris population in Earth’s orbit. To ensure the long-term sustainability of outer space activities, the relevant stakeholders need to collaborate with each other to solve challenging issues and find meaningful solutions. This article aims to conduct a bibliometric analysis to provide information and insights to guide the alignment of all stakeholders towards space sustainability in the context of near-Earth outer space. The software VOSviewer is chosen to analyse the selected 205 journal articles from Scopus database during 2003–22. The results show the publication trends, the leading sources of publications and the country collaboration network. The discussion based on the selected articles can inform emerging theories that can underpin the development of the space sustainability concept. In conclusion, this analysis reveals the current scientific research and proposes meaningful theories for further research and recommendations.

Overview and Key Technology of the Membrane Drag Sail for Low Earth Orbit Satellite Deorbit

With the escalating frequency of space activities, particularly the launch of constellation satellites, the amount of space debris experienced gradually increases, posing threats to the safety and sustainability of the space environment. To counteract the growth of debris, active deorbit devices are imperative for spacecrafts. In low Earth orbit (LEO), the drag sail device has emerged as a highly effective solution due to its ability to increase the spacecraft’s windward area, facilitating rapid deorbit by leveraging atmospheric drag as the primary perturbation. In this study, recent developments of membrane drag sail deorbit technology for LEO satellites are summarized, as well as the current problems such as attitude instability, dangerous space environment, and folding and unfolding issues. Moreover, crucial technologies such as modeling and simulation of deorbit efficiency, attitude stabilization, collision risk analysis and protection design, sail surface atomic oxygen protection design, and folding and unfolding of the drag sail are discussed. Finally, the development trends and technology applications of membrane drag sail deorbit for LEO satellites are presented.

Авіаційна та космічна галузі в постіндустріальному розвитку

The article raises the issue of the relevance of the development of international cooperation in the aerospace industry, taking into account the trends of post-industrial society, the development of artificial intelligence, and the transformation of the world society. It is specified that one of the key indicators of the transition from an industrial to a post-industrial society is the active development of the service sector and the importance of education and the knowledge economy, which come to the fore. The economy of post-industrial societies is dominated by innovative sectors such as high-performance industries, high-quality and innovative services as a share of GDP, and a larger share of the population employed in the service sector than in industrial production. A country with a highly developed aerospace industry demonstrates its national strength, scientific and technological innovation, effective public policy, strategic vision and principles of national security. At the international level, the leading countries of the world have identified the coordination of space activities and the development of aerospace industry as a priority of the national level. Ukraine has a complete space complex (rockets, spacecraft, ground control centers, data processing centers) and most aviation platforms (reusable spacecraft, some passenger aircraft, military transport, transport-only), has the potential for construction, research and development, can organize the production, operation and use of the rocket, space and aviation technology. The aviation industry and the space industry outline the long-term prospects for the development of the country’s economy. In terms of development, the aerospace industry is ahead of other industries and plays a vital role in modern civilization. The development of the aviation industry is urgent for Ukraine, including the development of ground airport infrastructure, air transport and a combination of ground and air transport.