Acta Astronautica最新文献

{"title":"Thermal Property Engineering of Lunar Regolith via Spark Plasma Sintering","authors":"J.A. Foster,&nbsp;K.L. Yung","doi":"10.1016/j.actaastro.2026.10.033","DOIUrl":"10.1016/j.actaastro.2026.10.033","url":null,"abstract":"<div><div>The extreme logistical challenges of Lunar exploration and habitation encourage in situ resource utilisation. Spark Plasma Sintering is a technique capable of rapidly consolidating Lunar regolith without additives, leveraging the vacuum conditions of the Lunar surface. The manufactured components could be used for thermal energy storage, construction, or precision engineering, applications that are sensitive to how the thermal properties vary across the Lunar temperature range of -120°C to 120°C. Understanding how the sintering process influences the thermal properties is essential for optimal design and performance. This study investigates the effects of SPS process parameters on the coefficient of thermal expansion, heat capacity, and thermal conductivity of sintered regolith simulants. Both a mare and a highland simulant were sintered to expand the current body of knowledge with this data and with evaluation of the implications for in situ utilisation. The findings show that sintering temperature is the most influential factor affecting all three thermal parameters. Variations in thermal conductivity and heat capacity with density suggest that engineering trade-offs are necessary to optimise the thermal performance of thermal storage systems, structural materials, and precision components.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"251 ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149201317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multidimensional Spaceflight Stressors Disrupt Blood-Brain Barrier: A Comprehensive Review of Molecular Mechanisms","authors":"Yitong Guo, Rong Liang, Jiajia Yang, Dong Ming","doi":"10.1016/j.actaastro.2026.10.020","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.020","url":null,"abstract":"Spaceflight exposes astronauts to multiple stressors—microgravity, cosmic radiation, elevated CO<ce:inf loc=\"post\">2</ce:inf>, and social isolation—that can disrupt blood–brain barrier (BBB) integrity. This review examines the molecular mechanisms by which each stressor targets the neurovascular unit. Microgravity destabilizes endothelial tight junctions via Rac1/Wave2/Arp3 suppression; radiation triggers oxidative DNA damage and PI3K/Akt-driven inflammation; hypercapnia downregulates tight-junction proteins and disrupts aquaporin-4 polarity; and social isolation compromises claudin-5 while inducing astrocytic remodeling. These pathways converge on shared nodes—oxidative stress, MMP-9 activation, and cytoskeletal disruption—that may amplify barrier dysfunction. We evaluate potential countermeasures, including Rac1 agonists, PI3K/Akt inhibitors, antioxidants, organ-on-chip platforms, and fluid biomarkers (GFAP, S100β), and propose that integrating standardized organ-chip systems with real-time in-flight biomarker monitoring could accelerate countermeasure development and help preserve CNS health on long-duration missions.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"33 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plug-type nozzle design and performance characterization for liquid-kerosene rotating detonation engines","authors":"Quan Zheng, Xinpei Han, Haolong Meng, Yuqiang Liu, Qiao Wang, Chunsheng Weng","doi":"10.1016/j.actaastro.2026.10.031","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.031","url":null,"abstract":"The nozzle is critical for converting combustion energy into thrust in rotating detonation engines (RDEs), yet its design remains challenging due to the inherently unsteady and periodically oscillating flow field. This study presents the first experimental demonstration of plug-type nozzles applied to a liquid-kerosene/oxygen-enriched air RDE operating under ambient back-pressure conditions. Three plug nozzles with design pressure ratios of 4, 6, and 8 were designed based on time-averaged flow parameters and systematically tested to evaluate their effects on combustion characteristics and thrust performance. An Equivalent Available Pressure (EAP)-based method is established to assess the nozzle expansion state and quantify its deviation from the design point under unsteady inflow. Cold-flow results reveal that the total pressure recovery coefficient increases with decreasing throat area, ranging from 0.47 to 0.78. During hot-fire operation, the nozzle transitions from over-expanded to under-expanded modes as mass flux increases, with the transition point coinciding with the design condition. Notably, the performance improvement rate—in terms of thrust, specific impulse, and nozzle efficiency—is substantial when approaching the design point from the over-expanded side, but diminishes markedly once the nozzle enters the under-expanded regime. Furthermore, the plug nozzle exhibits superior efficiency in the over-expanded state, attributed to its inherent self-compensating capability against pressure oscillations. These findings suggest that conventional nozzle design practice aiming for perfect expansion at a single design point may be suboptimal for RDE applications; instead, an over-expanded operational window should be prioritized in future plug-nozzle design for detonation-based propulsion systems.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"2 1","pages":"351-363"},"PeriodicalIF":3.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COMPARATIVE STUDY OF MACHINE LEARNING ALGORITHMS IN THE DIAGNOSTICS OF ELECTROMECHANICAL ACTUATORS FOR SAFETY ENHANCEMENT IN AEROSPACE SYSTEMS","authors":"G.S. Veresnikov,&nbsp;S.G. Bazhenov,&nbsp;V.I. Goncharenko,&nbsp;A.V. Skryabin","doi":"10.1016/j.actaastro.2026.10.032","DOIUrl":"10.1016/j.actaastro.2026.10.032","url":null,"abstract":"<div><div>The increasing use of aerospace systems highlights the need for developing diagnostic algorithms for electromechanical actuators in control systems. The reliable operation of electromechanical actuators is critical for ensuring the functionality of controlled object, which is essential for safe flight. This paper presents the results of a study on the application of machine learning technologies to develop classification models capable of identifying faults related to gear performance degradation of execution mechanisms. Training and test datasets were generated using a mathematical model of an electromechanical actuator, accounting for faults caused by changes in backlash, Coulomb friction, viscous friction, and key external factors such as temperature, supply voltage, and load. The parameter grid defining technical condition and external conditions was built using optimal space filling and full factorial design methods. The generated datasets were used to investigate a data processing pipeline, including: feature extraction, feature selection (filter and embedded methods) and subsequent building classification model using machine learning techniques. A total of 3990 combinations of data processing methods were generated. Classification models were built using the training dataset (optimal space filling), for which confusion matrices were obtained and F1-scores were calculated on the test dataset (full factorial design). As a result of large-scale computational studies heatmaps were built to visualize the effectiveness of different method combinations, quantitative distributions were developed to assess the relative frequency at which selecting a particular method leads to high classification model accuracy, the best-performing machine learning methods were identified.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"251 ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149201315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuous relaxation two-stage planning methods for dynamic threat evasion of spacecraft under fixed thrust maneuvering","authors":"Junjie Lu, Zhongjie Meng, Bo Liu, Zelin Cong, Qinwen Li, Jinxin Bai","doi":"10.1016/j.actaastro.2026.10.029","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.029","url":null,"abstract":"This paper addresses the challenge of evasive trajectory planning for spacecraft facing an actively approaching target, with the goal of enhancing autonomous safety during in-orbit maneuvering. A dynamic threat evasive trajectory planning method under fixed-thrust maneuvers is proposed. First, an orbital dynamics model for spacecraft evading an actively approaching threat is established. Considering multiple intercept corrections made by the threat target against the spacecraft’s evasive behavior, a dynamic time-series threat assessment method is designed. The minimum velocity increment required for the threat to intercept the spacecraft is computed, and then smoothly mapped to a continuous threat level. Second, to handle the on/off Boolean nature of fixed thruster, a binary continuous relaxation strategy is developed to convert the original mixed-integer programming problem into a continuous optimization problem. Through composite regularization, the proposed method drives the relaxed solution toward a 0/1 distribution while effectively limiting the number of thruster switches. Third, a two-stage planning framework based on an improved salp swarm algorithm is constructed. In the first stage, an enhanced algorithm with global exploration capability quickly obtains a coarse impulse timing and direction in the continuous space. In the second stage, a hybrid algorithm incorporating local search and constraint repair mechanisms performs fine optimization to ensure engineering realizability of the solution. Simulation results show that the proposed method can effectively avoid threats while ensuring the spacecraft returns to its target orbit. Compared with traditional mixed-integer programming methods, it achieves significant improvements in computational efficiency and performance metrics, providing an effective solution for enhancing spacecraft safety in complex orbital environments under fixed-thrust constraints.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"18 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The perspectives on space circular economy","authors":"Margot Clauss, René Laufer, Anna Öhrwall Rönnbäck","doi":"10.1016/j.actaastro.2026.10.005","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.005","url":null,"abstract":"The circular economy is gaining momentum among the space community since the rise of the new space era stresses the linearity of the industry. Spacecraft are made, launched, used, left in orbit, as debris, or deorbited, with most of their material dispersed in the atmosphere. It is crucial to understand the reasons why this momentum exists to build adequate answers. The state of the art of the space industry and its challenges determine the core drivers of the space circular economy, which shape its definition and objectives. Several space actors are starting to consider the space circular economy and are building on their own space circular economy perspective. Analyzing those perspectives permits the determination of core principles, objectives, and strategies investigated. They have the potential to build a commonly adopted and used framework necessary to successfully implement a long-term space circular economy.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"58 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PERFORMING ANTICOLONIAL SPACE: METHODS FROM PERFORMANCE STUDIES","authors":"Felipe Cervera","doi":"10.1016/j.actaastro.2026.10.002","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.002","url":null,"abstract":"As in other fields in the arts, humanities, and social sciences, performance studies has seen a significant increase in scholarly attention to de/anticolonial theory and practice. Arguments made by Bala [1], Teves [2], Arora [3], and Hussein [4], among others, highlight the importance of revising the discipline's methods to incorporate de/anticolonial gestures, whether physical or discursive, that unsettle colonial practices. Central to these arguments is a broad definition of performance (i.e., both as an object and as a methodological framework) that recognizes the wide variety of political actions expressed by artists and cultural practitioners, as well as by political leaders, scientists, entrepreneurs, and other public figures. The disciplinary emphasis that performance studies has on the material consequences of societal and individual actions (as opposed to merely their fictional or abstract representation) means that its frameworks are therefore expansively applicable, i.e. one can study a wide variety of actions as performative of larger societal, political, cultural and indeed technological regimes of power and knowledge. This paper argues that, with this methodological edge, performance studies can make a significant contribution to the current interdisciplinary momentum in the space humanities. Rather than treating cultural and artistic performances as critical representations or celebrations of the downfalls and virtues of contemporary space discourse, a performance-based framework for the space humanities enables the study of astronautical knowledge as performative of the epistemological frameworks that underpin it. The paper outlines three research and analysis methods commonly used in performance studies that could be applied to the social and anthropological study of astronautics and space science. These methods are (1) performance analysis (2) (2) (2) performance-as-research, and (3) the discovery/conquest scenario. When integrated into an anticolonial methodology for the space humanities, these approaches can expand the field’s critical toolkit to create imaginaries, projects, narratives, and institutions that envision space differently. A key part of this effort is including de/anticolonial gestures performed by cultural actors who, although they may not be immediately recognized as members of the traditionally exclusive “cosmic elites” (Dickens Ormrod [5]), nonetheless challenge the very concept of “outer space” through their practices and work.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"10 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-stage Bayesian inference for collapse load prediction of inflatable beams with slow leakage","authors":"Liang Zhang, Chaoxin Wu, Yipeng Ge, Zerong Cen","doi":"10.1016/j.actaastro.2026.10.011","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.011","url":null,"abstract":"Inflatable beams are promising lightweight load-bearing elements for space structures, yet their long-term reliability is threatened by inevitable slow leakage, which gradually reduces internal pressure and load-bearing capacity. Meanwhile, the failure risk of sensors in extreme environments leads to a decrease in the reliability of direct pressure monitoring, making the prediction of collapse loads extremely challenging. This study proposes a two-stage Bayesian inference framework that integrates bending experiments, finite element modeling, and a neural network surrogate model to achieve non-destructive prediction of collapse loads. The Bayesian inference process is decomposed into two decoupled stages to overcome the problem of non-unique inverse solutions. Initial buckling stage data are employed to validate an equivalent axial force representation and infer the unknown internal pressure. The surrogate model accelerates Markov Chain Monte Carlo sampling by replacing time-consuming finite element analysis. Multiple Results show that using the inferred internal pressure obtains more accurate collapse load predictions, with all prediction errors reduced — the maximum relative error reduction being 85.10%, effectively avoiding unsafe overestimation. The framework provides a practical strategy for reliable collapse prediction of inflatable beams with unknown internal pressure, and offers a feasible method for digital twin applications in structural health monitoring during long-term service.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"12 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attitude error estimation and coupled filter integration","authors":"Mehmet Esit, Halil Ersin Soken","doi":"10.1016/j.actaastro.2026.10.003","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.003","url":null,"abstract":"Integrating the attitude filter with one of the static attitude determination methods, such as QUEST, is a method that has several practical advantages. These advantages include but are not limited to quick convergence, fusing multiple vector measurements in a computationally efficient way, and providing contingency solutions for star trackers. When star tracker quaternion measurements are used in the attitude filter, the overall architecture becomes similar, too. First, this article provides an overview of attitude error estimation based on Wahba’s problem, examining both an eigenvalue-based formulation and an alternative algebraic approach. This attitude error estimation builds the foundation for a coupled filtering approach proposed in the latter part of the article. The attitude error estimation algorithm is integrated with the filter in the error domain so that it estimates the attitude error. The proposed approach simplifies the overall algorithm while still preserving the advantages of static attitude determination and filtering integration, such as quick convergence. It also provides an alternative for autonomous star trackers’ quaternion estimation algorithms when fed with the gyro measurements. Finally, the attitude filtering performance with the three approximations of the maximum eigenvalue involved in this proposed attitude error estimation formulation is compared. Numerical simulations, including a Monte Carlo robustness analysis, show that the approximation <mml:math altimg=\"si238.svg\" display=\"inline\"><mml:msub><mml:mrow><mml:mi>λ</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub></mml:math> achieves the best overall robustness while being the fastest to compute.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"5 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On-Orbit Refueling Overview and Value Study for Economic Sustainability","authors":"Pietro Verga, Emanuele Casciaro, Paolo Bettini","doi":"10.1016/j.actaastro.2026.10.006","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.10.006","url":null,"abstract":"In recent years, on-orbit servicing has assumed a relevant position within the space industry, with agencies, such as the Italian Space Agency (ASI), and companies, i.e. Orbit Fab, expecting on-orbit refueling to be the next breakthrough in this sector. The service not only enhances the performance and lifespan of satellites and interplanetary vehicles, but also leads to deeper space exploration and development of space-based infrastructures. More-over, it gives the opportunity to increase the allocated payload mass by re-ducing the amount of propellant boarded, given that the refueling operation is already been considered at mission design level. Successively to a broad historical review about on-orbit refueling and former economic studies, this work, differently from the previous analyses, investigates the economic sus-tainability of a mission architecture that incorporates the service among the phases defined during design. Financial methods are employed to suitably describe each considered scenario. Specifically, the real option approach ap-plies financial option-pricing models to capital budgeting and it is suitable for volatile economic environments characterized by long-term consequences of a decision, while the Net Present Value (NPV) is computed when future cash flows are predictable and an appropriate discount rate can be estimated.","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"14 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}