Acta Astronautica最新文献

{"title":"The impact of actual and simulated space conditions on the gut microbiome and the modulatory role of nutrition: A systematic review and meta-analysis","authors":"Makreli Maria-Eleni,&nbsp;Charidemou Evelina","doi":"10.1016/j.actaastro.2026.01.006","DOIUrl":"10.1016/j.actaastro.2026.01.006","url":null,"abstract":"<div><h3>Purpose</h3><div>This study aimed to evaluate the effects of spaceflight and simulated space environments on the human gut microbiome by examining also the role of nutrition as a modulator in these alterations.</div></div><div><h3>Methods</h3><div>Relevant studies were identified through searches of PubMed, PubMed Central and Scopus from 2000 through July 10, 2025. Alterations to gut microbial diversity, the Firmicutes-to-Bacteroidetes (F/B) ratio, and other physiological values were reported. Statistically significant fluctuations in gut microbial composition were collected as mean differences and standard deviations and statistically analysed with 95 % confidence intervals (CI) using SPSS. Heterogeneity was assessed using the I² statistic. The link between these changes and other confounding factors was statistically evaluated.</div></div><div><h3>Results</h3><div>15 studies were included, with 3 being actual spaceflights and 12 being space environment simulations. 6 out of the 11 studies that examined gut microbial diversity were included in the meta-analysis, and they presented a non-statistically significant trend toward increased diversity during the control phase (Hedges' g: −0.05, p = 0.84). The environment appeared to influence the observed alterations, with actual spaceflights having a greater impact (Hedges' g: 0.58, p = 0.19). Nutritional strategies, particularly those rich in fiber, probiotics, and vitamin D, were linked with stabilised or improved microbiome diversity, in contrast to ultra-processed foods (UPFs).</div></div><div><h3>Conclusion</h3><div>Overall, the findings suggest a negative effect of space conditions on gut microbial diversity, along with an adaptive microbiome response, with targeted nutritional interventions being promising in preserving gut health. Further research is needed to develop effective countermeasures that can be applied in both space and on Earth.</div></div><div><h3>Systematic review registration</h3><div><span><span>https://www.crd.york.ac.uk/PROSPERO/</span><svg><path></path></svg></span>, identifier CRD420251068366.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 277-288"},"PeriodicalIF":3.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962163","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":"Al-B alloy as a composite propellant additive: The role of B in combustion and agglomeration","authors":"Yanfeng Jiang ,&nbsp;Zhan Wen ,&nbsp;Lu Liu ,&nbsp;Mingming Zhan ,&nbsp;Wen Ao","doi":"10.1016/j.actaastro.2026.01.032","DOIUrl":"10.1016/j.actaastro.2026.01.032","url":null,"abstract":"<div><div>An experimental investigation was conducted to examine the effects of Al-B alloy additives on the ignition, combustion, and agglomeration characteristics of composite propellants. The properties of four Al-B alloys with different B contents (5 %, 20 %, and 50 % B) were comparatively evaluated against pure Al powder using Thermogravimetric-Differential Scanning Calorimetry, ignition research by CO₂ laser, combustion experiments under high-pressure, Scanning Electron Microscopy, and X-ray Diffraction. B addition markedly accelerates the oxidation of Al, increases the total heat release, and shortens ignition delay. Regarding combustion performance, Al-B alloy propellants exhibited higher burning rates, with the alloy containing 50 % B (Al/B = 1:1) showing the most pronounced improvement and a relatively low pressure exponent. In terms of agglomeration suppression, alloys with lower B content (e.g., 5 % B) effectively decreased particle size combustion products size. However, increased B content led to greater formation of B₂O₃ in the combustion products, whose adhesive properties promoted particle agglomeration. Considering a trade-off among ignition delay, burning rate, and agglomeration inhibition, Al-B alloy with 50 % B content demonstrates the greatest potential for enhancing the overall performance of composite propellants.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 119-126"},"PeriodicalIF":3.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995671","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":"Effects of particle breakup on aluminum combustion and SRM performance under different motor scales","authors":"He Chen ,&nbsp;Xueting Wu ,&nbsp;Wenjing Yang ,&nbsp;Shuiping Zhou ,&nbsp;Huailong Zhang ,&nbsp;Peijin Liu","doi":"10.1016/j.actaastro.2026.01.038","DOIUrl":"10.1016/j.actaastro.2026.01.038","url":null,"abstract":"<div><div>Particle breakup phenomena are commonly observed during the operation of solid rocket motors and have a pronounced influence on the evolution of the combustion flow field and the prediction of motor performance, yet quantitative treatments remain limited. This study introduces a comprehensive aluminum particle combustion model that integrates the classical Wave Breakup theory to investigate the breakup behavior of aluminum/alumina droplets across motors of varying scales. Numerical results reveal that in high-shear regions, particularly the nozzle convergent section, molten droplets undergo substantial aerodynamic breakup, producing finer child droplets that shift the particle size distribution toward the micron scale and trigger secondary combustion. The attendant increase in specific surface area enhances aluminum combustion efficiency and modifies the reactive flow structure, producing localized temperature rises and broader particle dispersion. Notably, the breakup characteristics exhibit strong scale-dependent behavior, with both motor size and initial particle diameter governing the location, intensity, and consequent combustion enhancement of the breakup process. Relative to simulations ignoring breakup, the model predicts higher particle-phase velocity and thrust, a slight reduction in gas exhaust velocity due to intensified interphase momentum exchange, and a net increase in total thrust—effects that are particularly pronounced in smaller-scale motors. These findings offer a physical basis for improving the design, performance forecasting, and energy utilization of solid rocket motors.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 236-250"},"PeriodicalIF":3.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001025","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":"Segmentation of the spacecraft transfer problem based on overdetermined and continuity constraints using the theory of functional connections","authors":"A.K. de Almeida Jr.","doi":"10.1016/j.actaastro.2026.01.028","DOIUrl":"10.1016/j.actaastro.2026.01.028","url":null,"abstract":"<div><div>This paper introduces a segmented approach for solving constrained orbit transfer problems. The segments are connected through continuity constraints under the Theory of Functional Connections (TFC) mathematical framework that performs linear functional interpolation. This approach is further enhanced by a general vector formulation, from where the constrained functional is derived considering also a set of linear <em>overdetermined constraints</em>. Since we constrain vector instead of coordinates, this methodology allows to apply TFC to multiple and complex constraints composed by any types of nonlinear components included. We demonstrate the effectiveness of the method on Earth-to-Moon transfers, showing that this segmented approach achieves solutions with several orders of magnitude greater accuracy and efficiency in comparison with unsegmented orbit transfers.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 251-263"},"PeriodicalIF":3.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014796","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":"Functional prioritization strategies and tradespace considerations for a self-reliant deep space habitat","authors":"Annika E. Rollock,&nbsp;David M. Klaus","doi":"10.1016/j.actaastro.2026.01.035","DOIUrl":"10.1016/j.actaastro.2026.01.035","url":null,"abstract":"<div><div>As human spaceflight missions extend further from Earth, reliance on ground becomes increasingly impractical due to communication delays with potential for occultations and the long transit time required for resupply. For these missions, incorporating autonomous capabilities into the habitat may offer enabling solutions to the challenges of deep space. Although it may be tempting to leverage autonomous systems wherever possible, the added complexity can also lead to new failure modes and/or schedule and budget overruns. Therefore, prioritizing those functions that are a) most critical to mission success and b) currently dependent on ground teams, can help to determine where emergent technologies offer the greatest potential return on investment toward self-reliant operations. This work presents a flexible, needs-based framework for prioritizing habitat functions according to their current Earth-reliance and criticality in order to assess where novel solutions may be most beneficial to enabling autonomous operations within the constraints of deep space. Proposed figures of merit for prioritizing spacecraft functions are defined, and can be used to directly compare technology solutions. Finally, a high-level demonstration is performed through a case study of the repair of the External Active Thermal Control System (EATCS) onboard the ISS in 2017. The evaluation framework and case study example presented here are intended to serve as a customizable template that can be adapted to mission-specific needs and constraints.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 193-204"},"PeriodicalIF":3.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014258","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":"A double-layer sensing system combining thin-film resistor and acoustic emission networks towards an in situ real-time quantitative monitoring of hypervelocity impact","authors":"Pinliang Zhang ,&nbsp;Qian Yu ,&nbsp;Qiang Wu ,&nbsp;Jilong Peng ,&nbsp;Jingtai Li ,&nbsp;Shun Lu ,&nbsp;Menglong Liu ,&nbsp;Junfeng Wang ,&nbsp;Yu Jiang ,&nbsp;Rong Song","doi":"10.1016/j.actaastro.2026.01.025","DOIUrl":"10.1016/j.actaastro.2026.01.025","url":null,"abstract":"<div><div>Massive orbital debris consisting of remnants from previous missions orbit the Earth. The acquisition of data pertaining to the orbital debris is of paramount importance for the development and validation of debris environment models. In this study, a novel <em>in situ</em> real-time quantitative hybrid perception method for hypervelocity impact (HVI) from space debris is proposed, integrating a thin-film resistive grid with acoustic emission (AE) technology. The thin-film resistive grid is fabricated by etching a cross-shaped array of micrometer-scale resistive wires on the respective sides of a polyimide film. In the event of the film being penetrated by debris and the resistive wires being broken, the electrical resistance status of the wires can then be used to determine the location and size of the debris. Following the penetration of the thin-film layer, the debris strike a second aluminum plate equipped with an AE sensor array. The arrival times of the acoustic signals are processed using a hyperbolic localization algorithm to determine the HVI location. By correlating the time and location data from both layers, the velocity and direction of HVI can be derived. This facilitates the quantitative perception of multiple debris parameters. Then, the HVI numerical simulations, which combine smooth particle hydrodynamics and finite element method, are performed to validate the effectiveness of the proposed perception approach. Finally, a physical prototype of the <em>in situ</em> debris detector is developed for experimental validation. Two ground-based two-stage light gas guns are used to propel several projectiles with diameters ranging from hundreds of micrometers to several millimeters. The average absolute errors for the three tested cases are 0.10 km/s for the projectile velocity, 1.0° for the impact angle, and 0.30 cm for the HVI location at the aluminum plate, demonstrating the effectiveness for multi-parameter perception of space debris.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 289-300"},"PeriodicalIF":3.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962164","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":"Launch window design for crewed lunar mission with lunar orbit rendezvous and two launches","authors":"Tianshan Dong ,&nbsp;Xiaobing Ma ,&nbsp;Wenyan Zhou ,&nbsp;Lin Lu","doi":"10.1016/j.actaastro.2026.01.020","DOIUrl":"10.1016/j.actaastro.2026.01.020","url":null,"abstract":"<div><div>Lunar Orbit Rendezvous (LOR) is a crucial mode for crewed lunar missions. Unlike the Apollo mission, a variant of LOR involving two launches and the assembly of modules in lunar orbit has emerged as a notable pattern in recent lunar return missions. This paper presents a methodology for determining the launch window of a crewed lunar mission using LOR with two launches. First, nominal launch windows are defined by constructing its calculation model based on the flight scheme and integrated launch windows are introduced considering a delay strategy. Second, a method for determining nominal launch windows based on mission geometry is proposed, which solves the nominal launch window in a tiered analytical process by constraints’ temporal geometry. Finally, the integrated launch windows are first estimated by orbital plane matching and then solved by introducing virtual planes. Numerical simulations for nominal launch windows and integrated launch windows validate the proposed method and the satisfaction of the constraints. The methodology offers a systematic solution to the launch window for crewed lunar missions with lunar orbit rendezvous and two launches and addresses the integrated launch window for spacecraft under a complex delay strategy.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 58-73"},"PeriodicalIF":3.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962431","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 stabilization of slender payloads in partial space elevator transport by super-twisting sliding mode control","authors":"Gefei Shi ,&nbsp;Zheng H. Zhu","doi":"10.1016/j.actaastro.2026.01.004","DOIUrl":"10.1016/j.actaastro.2026.01.004","url":null,"abstract":"<div><div>This work develops the rigid-flexible coupled dynamic model of a partial space elevator transporting a slender structural payload by the climber during cross-orbit payload transfer. The payload is modeled by Euler–Bernoulli beam theory, and analysis shows that even small bending deformation of the payload can induce large attitude motion of the climber-payload assembly due to strong orbit-rigid–flexible coupling. To quantify this behavior, a closed-form expression is derived for the steady bending deformation of the payload under the gravity-gradient effect. Building on this analytical insight, a nonlinear compensation control torque is formulated to suppress attitude motion caused by rigid–flexible coupling without requiring impractically large control torques. To enhance control robustness, a super-twisting sliding mode control scheme is proposed by embedding the forward control law within a Lyapunov stability framework. This combined strategy eliminates residual dynamics and reduces the chattering inherent in sliding mode control while ensuring global attitude stability. Numerical simulations verify that the proposed strategy significantly reduces the attitude excursions of the climber-payload assembly while keeping the required control torques within the capacity of reaction wheels on the climber (rigid body). Overall, this work establishes a nonlinear dynamic framework for tethered transport systems with slender structure payloads and provides the first validated control solution enabling safe, stable, and efficient operation of partial space elevator transporting slender structure payloads.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 491-503"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978441","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":"Numerical study on zonal combustion characteristics in supersonic combustor under asymmetric injection scheme","authors":"Xiaosi Li ,&nbsp;Junlong Zhang ,&nbsp;Guowei Luan ,&nbsp;Youyin Wang ,&nbsp;Hongchao Qiu ,&nbsp;Wen Bao","doi":"10.1016/j.actaastro.2025.12.064","DOIUrl":"10.1016/j.actaastro.2025.12.064","url":null,"abstract":"<div><div>The injection scheme has a significant effect on the mixing and combustion of the fuel, as well as the spatial distribution of the main combustion zone, which is crucial for the performance of the scramjet. In this study, the zonal combustion under several typical asymmetric strut/wall combined fuel injection schemes was numerically investigated. The flow field characteristics, mixing and combustion performance, the combustor parameters distributions, as well as the impact of zonal combustion on the aerodynamic performance of the nozzle were analyzed. The results indicate that zonal combustion can be established in a supersonic combustor through zonal fuel injection, wherein combustion zones and non-reacting zones coexist in the circumferential direction of the combustor while exhibiting distinct flow and combustion characteristics. Besides, at an identical equivalence ratio, zonal fuel injection schemes not only yield lower mixing and combustion efficiencies compared to a uniform injection scheme, but also alters both the wall pressure distribution along the combustor and the gas parameter distribution at combustor outlet. Ultimately, zonal combustion affects the aerodynamic performance of scramjet nozzles, such as lift and lateral force. The analysis results of zonal combustion in this paper were beneficial to the optimization of asymmetric injection scheme in supersonic combustor for future investigations and offer a novel perspective for flight control in hypersonic vehicles.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 260-277"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145893822","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":"Numerical simulation and experimental study of lunar surface drilling sampling based on JKR contact model","authors":"Jia Fu ,&nbsp;Haitao Luo ,&nbsp;Yuxin Li ,&nbsp;Huadong Li ,&nbsp;Dehui Li ,&nbsp;Teijun Wang","doi":"10.1016/j.actaastro.2025.12.062","DOIUrl":"10.1016/j.actaastro.2025.12.062","url":null,"abstract":"<div><div>With the smooth progress of lunar exploration programs, lunar sampling has become a major research focus in current deep space missions. Sampling techniques and methods are the key to lunar surface sampling tasks. However, conventional drilling simulation analyses are often difficult to accurately match with experimental results, which makes research on drilling simulation modeling highly significant. For the simulation of lunar regolith drilling and sampling, the accurate calibration of discrete element parameters of lunar soil was systematically carried out based on the Johnson-Kendall-Roberts (JKR) contact theory. A discrete element model consistent with the lunar highland regolith characteristics returned by the Apollo missions was established and verified through angle of repose experiments. Subsequently, an external helical hollow drill rod was designed as the drilling-sampling tool, and a coupled discrete element–multibody dynamics simulation model of the interaction between the drilling-sampling tool and lunar soil particles was established to predict the variation of drilling loads during penetration. A drilling-sampling experimental platform was then designed and built to explore the relationship between drilling torque variation and feed rate, rotation speed, as well as the physical properties of lunar regolith. The results were compared with numerical simulation outcomes, showing errors below 20 %. These research findings provide important technical support and parameter references for practical lunar surface sampling missions.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 314-324"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895524","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}