Acta Astronautica最新文献

{"title":"Learning-based optimal guidance for spacecraft close-proximity operations with certified stability","authors":"Kun Wang ,&nbsp;Roberto Armellin ,&nbsp;Adam Evans ,&nbsp;Harry Holt ,&nbsp;Zheng Chen","doi":"10.1016/j.actaastro.2026.02.009","DOIUrl":"10.1016/j.actaastro.2026.02.009","url":null,"abstract":"<div><div>Machine learning techniques have demonstrated their effectiveness in achieving autonomy and optimality for nonlinear and high-dimensional dynamical systems. However, traditional black-box machine learning methods often lack formal stability guarantees, which are critical for safety-sensitive aerospace applications. This paper proposes a comprehensive framework that combines control Lyapunov functions with supervised learning to provide certifiably stable, time- and fuel-optimal guidance for relative motion rendezvous maneuvers. A novel neural candidate Lyapunov function is first developed that ensures positive definiteness. Subsequently, a control policy is formulated wherein the thrust direction is chosen to minimize the time derivative of the Lyapunov function, while the throttle level is set to the minimum required value. This approach guarantees that all control Lyapunov function loss terms are either naturally satisfied or replaced by the derived control policy. To jointly supervise the Lyapunov function and the control policy, a simple loss function is introduced, leveraging optimal state-control pairs obtained through a polynomial map based method. Consequently, the trained neural network not only certifies the Lyapunov function but also generates a near-optimal guidance policy, even for the bang–bang fuel-optimal problem. Furthermore, the framework is easily extensible to nonlinear control-affine systems. Extensive numerical simulations are presented to validate the proposed method.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"244 ","pages":"Pages 1-19"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134795","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":"Autonomous orbital maintenance using a supervised-learning-based target point approach","authors":"Xiaoyu Fu,&nbsp;Stefania Soldini","doi":"10.1016/j.actaastro.2026.02.008","DOIUrl":"10.1016/j.actaastro.2026.02.008","url":null,"abstract":"<div><div>Autonomous orbital maintenance is a fundamental component of spacecraft autonomy and has become an active area of research. This study investigates the feasibility of implementing an autonomous onboard Target Point Approach (TPA) for the stationkeeping of periodic orbits, enabled by supervised learning. A stochastic optimization framework based on the TPA is first employed to generate optimal stationkeeping parameters from a range of initial state deviations. Based on these solutions, a large balanced dataset is constructed and used to train supervised learning models, including a multilayer perceptron (MLP) classifier to distinguish feasible from infeasible initial deviations, and MLP regressors to predict optimal stationkeeping parameters directly from initial deviations. The trained models are then integrated into an onboard TPA-based stationkeeping framework and evaluated through large-scale simulations involving 100,000 initial state deviations for a candidate Near Rectilinear Halo Orbit (NRHO). The simulation results demonstrate the effectiveness and robustness of the proposed approach. Furthermore, regularities observed from the large-scale stationkeeping analysis are identified and analysed, providing insight into the structure of the stationkeeping solution space and the learning-enabled decision process.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"244 ","pages":"Pages 141-155"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134796","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":"Advances in satellite thermal management systems: Challenges, innovations, and future directions","authors":"Shaik Zaidaan ,&nbsp;Ziyad Mulla ,&nbsp;Ruaa Nakkar ,&nbsp;Izhar Ullah ,&nbsp;Abrar H. Baluch ,&nbsp;Naef A.A. Qasem","doi":"10.1016/j.actaastro.2026.02.002","DOIUrl":"10.1016/j.actaastro.2026.02.002","url":null,"abstract":"<div><div>Effective thermal management is a cornerstone of satellite functionality, ensuring reliability and operational success in extreme space environments. This study comprehensively reviews the state-of-the-art in satellite thermal management systems, encompassing both passive and active techniques. Passive systems, including multilayer insulation (MLI), thermal coatings, and phase-change materials (PCMs), offer energy efficiency and reliability for baseline thermal regulation. Conversely, active systems, such as heat pipes, loop heat pipes (LHPs), and mechanically pumped fluid loops (MPFLs), provide dynamic adaptability to manage high-power loads and fluctuating environmental conditions. The paper also explores recent advancements in thermal management, such as smart materials, variable-emittance coatings, and hybrid systems that combine the benefits of both passive and active approaches. Furthermore, the integration of computational techniques, such as the finite element method (FEM) and computational fluid dynamics (CFD), has significantly enhanced the prediction of thermal performance. Experimental validation through thermal-vacuum testing is also discussed as a critical step in refining and ensuring the accuracy of these systems. By integrating advances in materials, technologies, and modeling methods, this review highlights emerging trends and challenges in satellite thermal management. The findings underline the importance of hybrid systems, material innovations, and computational modeling in addressing the evolving demands of next-generation satellite missions. Future directions are proposed to guide continued research and development in this vital area of aerospace engineering.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"244 ","pages":"Pages 82-121"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134814","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":"Direct ink writing of carbon fiber and AlSi10Mg reinforced lunar regolith simulant brick","authors":"Lu Zhang ,&nbsp;Ailing Xun ,&nbsp;Yingyu Chen ,&nbsp;Chao Xu ,&nbsp;Meng Zou ,&nbsp;Luquan Ren","doi":"10.1016/j.actaastro.2026.02.014","DOIUrl":"10.1016/j.actaastro.2026.02.014","url":null,"abstract":"<div><div>Additive manufacturing (AM) of small construction elements is promising for lunar construction due to the high costs and quality control challenges of large-scale AM in space. This study explores material extrusion of lunar regolith simulant bricks using Jilin University's mare lunar regolith simulant combined with PLA/DCM binder, carbon fiber (CF), and AlSi10Mg powders. We synthesize four types of inks with 24 formulations and print bricks, analyzing their microstructures and mechanical properties. Results show that adding an appropriate amount of CF and AlSi10Mg, either individually or concurrently, significantly improves compressive and tensile performance, including enhanced ductility from the yield plateau effect. The optimal formulation CF3%/AlSi10Mg15% shows a 216% increase in compressive strength (from 13.64 to 43.08 MPa) and a 167% increase in toughness (from 0.06 to 0.16J/mm³) compared to the control. Microstructural analyses confirm that CFs bridge micro-cracks and improve resistance to tensile stresses, while AlSi10Mg particles fill micropores, reinforcing mechanical properties synergistically. Furthermore, we construct interlocking bricks that can be assembled, showing improved compressive properties compared to the integral bricks. This research advances AM for lunar construction by focusing on lightweight and mechanically reinforced components within the In-Situ Resource Utilization concept.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"244 ","pages":"Pages 187-202"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153017","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":"Topology optimization and experimental validation of Linear Lorentz Actuator for non-contact spacecraft","authors":"Mingxuan Song ,&nbsp;He Liao ,&nbsp;Jinjin Xie","doi":"10.1016/j.actaastro.2026.01.072","DOIUrl":"10.1016/j.actaastro.2026.01.072","url":null,"abstract":"<div><div>The successful launch of the Xihe satellite and the accomplishment of its on-orbit experimental mission demonstrate that the non-contact spacecraft technology has emerged as a pivotal developmental trend in ultra-high-precision spacecraft control. To further enhance the control performance and reduce the launch mass of the spacecraft, this paper proposes a three-stage comprehensive structure optimization focusing on the mass and magnetic uniformity within the air-gap of the Linear Lorentz Actuator (LLA), which is the key actuator of non-contact spacecraft. Firstly, configuration optimization is performed via finite element simulation (FEM) to identify the optimal configuration among three candidate LLA configurations suitable for non-contact spacecraft. Subsequently, dimensional parameters of the optimal configuration are then refined to maximize magnetic uniformity. Furthermore, a composited-objective topology optimization based on density interpolation function is proposed to achieve global optimality. This yields an optimized LLA structure achieving a magnetic uniformity of 0.00057 and a 50% mass reduction in the magnetic conduction ring. Furthermore, a physical LLA prototype is fabricated based on the optimized design in this paper. Ground tests confirm that deviations between measured and theoretical magnetic field data in the air-gap did not exceed 4%, validating the effectiveness of the proposed optimization strategy.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"244 ","pages":"Pages 20-37"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146109806","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":"MEMS Gyroscope technology for Low-Earth orbit aerospace: technologies, environmental challenges, and emerging design strategies","authors":"Donghua Chen ,&nbsp;Yusen Guo ,&nbsp;Pengyu Huo ,&nbsp;Qiliang Li","doi":"10.1016/j.actaastro.2026.01.011","DOIUrl":"10.1016/j.actaastro.2026.01.011","url":null,"abstract":"<div><div>The rapid expansion of commercial Low-Earth Orbit (LEO) missions and mega-constellations has created stringent requirements for compact, cost-effective, and highly reliable inertial sensors. Micro-Electro-Mechanical Systems (MEMS) gyroscopes have emerged as pivotal components in Attitude Determination and Control Systems (ADCS) due to their superior SWaP-C advantages over traditional optical gyroscopes. However, the LEO environment imposes severe constraints, including extreme thermal fluctuations, ionizing radiation, vacuum-induced outgassing, and launch-induced mechanical stresses, all of which degrade long-term stability and reliability. This review provides a comprehensive analysis of recent advancements in MEMS gyroscope design, with emphasis on structural innovations, radiation-hardened electronics, advanced packaging, and data-driven signal processing methods that have been predominantly demonstrated through ground-based simulations and laboratory validations. This paper further examines their adoption in commercial satellite constellations, remote sensing, and reusable platforms, and highlights emerging trends such as hybrid fiber-optic/MEMS systems and digital-twin concepts for design optimization and performance assessment, while explicitly distinguishing demonstrated results from conceptual or simulation-based studies. Special attention is given to LEO-specific environmental degradation mechanisms and mitigation strategies through material selection, circuit hardening, and redundant architecture. The review concludes by outlining future directions in sensor miniaturization, intelligent self-calibration, and resilient system integration, and by identifying key validation gaps for learning-based and digital-twin-enabled approaches under space environmental constraints, underscoring MEMS gyroscopes’ critical role in enabling next-generation spaceborne navigation and control. This work aims to guide researchers and developers in creating robust, space-grade MEMS inertial solutions for commercial aerospace applications.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 280-290"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902737","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":"Flexible PVA/BA gel for passive radiation shielding in spacesuit applications beyond LEO","authors":"Lucia Lambertini ,&nbsp;Maria Gabriella Santonicola ,&nbsp;Susanna Laurenzi","doi":"10.1016/j.actaastro.2026.01.066","DOIUrl":"10.1016/j.actaastro.2026.01.066","url":null,"abstract":"<div><div>Protection of astronauts from intense space radiation during long-term missions to the Moon or Mars remains a critical challenge. With space agencies planning permanent lunar bases as gateways for deep-space exploration, enhancing radiation shielding in spacesuits during extravehicular activities (EVAs) is essential. This study explores the feasibility of integrating poly(vinyl alcohol) (PVA)-based gels as an intermediate shielding layer between the pressure bladder garment (PBG) and the liquid cooling and ventilation garment (LCVG), without altering suit geometry or increasing layer thickness. Due to their high water content, PVA-based gels combine flexibility, softness, and ductility with effective radiation attenuation. Experimental analyses compared the physical and mechanical properties of PVA gels to nylon, the primary material of PBG and LCVG. The gels exhibited similar density and thermal conductivity but demonstrated superior deformability, achieving elongations up to ∼65 % despite a lower Young's modulus. Numerical simulations performed with the OLTARIS confirmed the shielding potential of the proposed configuration. While protection against Galactic Cosmic Rays (GCR) remained limited due to their high penetration depth, the inclusion of PVA-based gel layers significantly reduced proton doses from Solar Particle Events (SPE), indicating their potential as an effective, lightweight enhancement to current spacesuit designs.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 149-161"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072618","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":"Rhombus facet design of fan-fold deployable reflector","authors":"Tadashi Masuoka ,&nbsp;Satoru Ozawa ,&nbsp;Takahiro Kuhara ,&nbsp;Yuji Yamagata ,&nbsp;Nobuaki Minami ,&nbsp;Kazuyuki Nakamura","doi":"10.1016/j.actaastro.2026.01.069","DOIUrl":"10.1016/j.actaastro.2026.01.069","url":null,"abstract":"<div><div>This paper presents an efficient method for designing the rhombus-shaped facets of a parabolic reflector. An approximate solution is derived to calculate the RMS error induced by mesh deformation. Finite Element Analysis (FEA) is conducted by modeling a single rhombus facet to validate the approximate solution. The FEA results show good agreement with the approximate solution in terms of maximum facet deformation. Furthermore, the RMS error of an actual 1 m-scale reflector was measured, revealing a difference of only 4.5 % between the measured and estimated values. Finally, the facet length and angle are designed to satisfy the surface accuracy requirements for different frequency bands using the proposed method.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 305-314"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089662","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 multi-objective evolutionary optimization for infrared image reconstruction and typical thermal response selection in hypervelocity impact damage detection","authors":"Zhongbao Yan ,&nbsp;Chun Yin ,&nbsp;Xuegang Huang ,&nbsp;Jiuwen Cao ,&nbsp;Yuanhao Zhang","doi":"10.1016/j.actaastro.2026.01.051","DOIUrl":"10.1016/j.actaastro.2026.01.051","url":null,"abstract":"<div><div>The complex damage caused by hypervelocity impact poses significant challenges for spacecraft damage detection. This paper presents a novel method for detecting hypervelocity impact damage in spacecraft based on infrared nondestructive testing, which utilizes transient thermal response data and designs an adaptive classification model based on kernel density estimation to effectively distinguish different types of defect information. Additionally, the paper addresses the issue of extracting typical transient thermal responses from various defect types and constructs a multi-objective optimization function based on intraclass representativeness and interclass distinctiveness. The proposed multi-objective evolutionary optimization algorithm, combined with the <span><math><mi>α</mi></math></span>-shape method, neural networks, and vertical distance measures, dynamically adjusts the weight vectors to optimize the distribution of solutions and balance convergence and diversity, resulting in higher quality typical transient thermal responses. Experimental results validate the effectiveness of the proposed method on real hypervelocity impact specimens, successfully obtaining defect images of different types.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 46-60"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033456","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":"Microgravity-induced alterations in left atrial hemodynamics and thrombogenic risk: Insights from healthy and atrial fibrillation models","authors":"Grace Hoeppner ,&nbsp;Ahmad Bshennaty ,&nbsp;Brennan Vogl ,&nbsp;Ghasaq Saleh ,&nbsp;Mohamad Alkhouli ,&nbsp;Hoda Hatoum","doi":"10.1016/j.actaastro.2026.01.058","DOIUrl":"10.1016/j.actaastro.2026.01.058","url":null,"abstract":"<div><h3>Background</h3><div>Microgravity exposure alters cardiovascular loading, yet its impact on left atrial flow dynamics and thrombotic risk remains poorly understood. This study investigates how spaceflight-relevant microgravity-induced changes in cardiac outflow affect left atrial hemodynamics in healthy individuals and patients with atrial fibrillation.</div></div><div><h3>Methods</h3><div>Patient-specific left atrial models were generated for three healthy individuals and three AF patients. Computational fluid dynamics (CFD) simulations were performed using each patient's baseline mitral outflow waveform and two modified waveforms representing short- and long-duration post-flight cardiac loading changes derived from echocardiographic observations. Hemodynamic metrics included left atrial velocity, time averaged wall shear stress, oscillatory shear index, relative residence time, and stasis volume, which were used to assess thrombogenic flow conditions.</div></div><div><h3>Results</h3><div>Post-flight, microgravity-associated modifications to mitral outflow conditions produced distinct hemodynamic responses across cohorts. In healthy individuals, short-duration post-flight loading reduced time-averaged wall shear stress from 1.51 to 1.00 Pa and increased velocity-defined stasis from 19.6 % to 64.2 %, indicating substantially reduced atrial washout. Under long-duration post-flight conditions, these metrics recovered toward or above baseline values (time-averaged wall shear stress 1.68 Pa; stasis 18.5 %), consistent with hemodynamic adaptation. In contrast, patients with atrial fibrillation exhibited high baseline stasis and showed minimal changes in time-averaged wall shear stress, oscillatory shear, or relative residence time across all loading conditions. Across all cohorts, the left atrial appendage consistently demonstrated the lowest shear and highest residence time.</div></div><div><h3>Conclusion</h3><div>These findings indicate that spaceflight-related microgravity exposure may transiently increase atrial flow stasis and thrombotic risk in individuals with normal atrial function, while individuals with atrial fibrillation remain in a persistently high-risk hemodynamic state that is relatively insensitive to microgravity-induced loading changes. This study provides the first patient-specific, chamber-level computational assessment of how spaceflight-documented cardiac adaptations influence left atrial hemodynamics and highlights the importance of accounting for duration-dependent hemodynamic adaptation when assessing thrombotic risk associated with human spaceflight.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 61-72"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081604","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}