Acta Astronautica最新文献

{"title":"Guidance strategies to deploy a Lunar Navigation Constellation from Gateway","authors":"Edoardo Maria Leonardi,&nbsp;Giulio De Angelis,&nbsp;Mauro Pontani","doi":"10.1016/j.actaastro.2025.02.023","DOIUrl":"10.1016/j.actaastro.2025.02.023","url":null,"abstract":"<div><div>In recent years, lunar constellation design and deployment has attracted a strong interest from the scientific community and the major space agencies. Indeed, a similar space infrastructure will represent a valuable asset for navigation and telecommunications purposes, useful to many robotic and human activities on the lunar surface. This study focuses on the analysis, design, and testing of three different feedback guidance strategies for the deployment of a lunar constellation, starting from Gateway. Orbit dynamics is modeled in a high-fidelity framework that employs planetary ephemeris and includes all the relevant orbit perturbations, i.e. the gravitational attraction due to Earth and Sun and several harmonics of the selenopotential. A constellation composed of 6 satellites is considered. They travel two distinct frozen lunar elliptical orbits, with proper mutual phasing. The first deployment strategy assumes that each satellite uses high-thrust propulsion to enter its operational orbit, with correct phasing. To do this, a single-parameter iterative Lambert-based algorithm is proposed as an effective real-time guidance technique, capable of determining all the (modest) intermediate correction maneuvers, to drive each satellite toward the desired position. The second deployment strategy assumes again the use of high thrust, while including two distinct phases: (a) orbit acquisition and (b) phasing. Specifically, in phase (a) three satellites are arranged as a cluster and travel toward their orbit, leveraging an original two-parameter iterative Lambert-based guidance. In phase (b), each vehicle performs phasing maneuvers, to get its correct position. The third deployment strategy includes again two phases: (a) low-thrust orbit acquisition and (b) phasing. In phase (a), the satellites are clustered and embarked onboard two cargo spacecraft, equipped with a low-thrust propulsion system. Nonlinear orbit control allows identifying a saturated feedback law for the low thrust magnitude and direction, and is shown to be effective as a guidance technique for each cargo vehicle. The closed-loop dynamical system at hand is proven to enjoy quasi-global stability properties, leveraging the Lyapunov stability theory. In phase (b), each satellite performs again phasing maneuvers, as in the preceding strategy. The three deployment strategies are evaluated in both nominal and nonnominal flight conditions, with the intent of showing their effectiveness while comparing their performance, in terms of propellant consumption and overall deployment duration.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 143-153"},"PeriodicalIF":3.1,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620368","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":"Spray characteristics of gel containing nanoparticles in impinging jet injectors","authors":"Qiyou Liu ,&nbsp;Penghui Li ,&nbsp;Hu Sun ,&nbsp;Dingwei Zhang ,&nbsp;Bingqiang Ji ,&nbsp;Lijun Yang ,&nbsp;Qingfei Fu","doi":"10.1016/j.actaastro.2025.02.051","DOIUrl":"10.1016/j.actaastro.2025.02.051","url":null,"abstract":"<div><div>Atomization is one of the critical challenges in the application of nanoparticle–laden gel propellants due to their high viscosity and complex rheological properties. This study investigates the rheological properties and atomization characteristics of gel containing varying concentrations of nanoparticles in impinging jet injectors. The rheological behavior of the gels was measured to characterize their shear-thinning properties. Impinging jet injectors with different structural parameters were designed and tested to evaluate the spray images, droplet size distributions, and discharge coefficients under various particle concentrations and flow conditions. Comparative analysis between water and particle–laden gels revealed that the high viscosity and complex rheological properties of gels hinder atomization, resulting in larger droplet sizes and reduced discharge coefficients. The results show that higher particle concentrations exacerbate these effects, but optimized injector design and increased jet velocity can mitigate the challenges by enhancing shear rates and reducing apparent viscosity. This study provides insights into gel formulation and injector design, offering practical guidance for advancing the application of gel propellants in propulsion systems.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 94-102"},"PeriodicalIF":3.1,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591509","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":"Comparison between direct and indirect measurements for externally wetted electrospray thruster with adapted analytical balance","authors":"Borja De Saavedra ,&nbsp;David Villegas-Prados ,&nbsp;Mick Wijnen ,&nbsp;Javier Cruz","doi":"10.1016/j.actaastro.2025.02.044","DOIUrl":"10.1016/j.actaastro.2025.02.044","url":null,"abstract":"<div><div>Ionic liquid electrospray propulsion systems are a promising technology for the rapidly growing small satellite market, potentially exhibiting high specific impulse and efficiency even at very low power. Direct performance characterization of electrospray thrusters is a challenging issue, given the low thrust and mass flow rate values. In this work, an analytical balance was modified for direct performance characterization of electrospray thrusters with sub-micronewton thrust uncertainty and sub-milligram-per-hour mass loss rate measurements. An electrostatic calibration device was built with commercial-off-the-shelf heat sinks as electrostatic combs, and characterized with high-precision calibration weights to correct the measurements of the balance in vacuum. The performance of an externally wetted electrospray thruster was obtained with simultaneous direct and indirect measurements by setting up the modified balance and a time-of-flight mass spectrometer in tandem. Direct thrust values of the order of <span><math><mi>μ</mi></math></span>N and in situ mass loss rates <span><math><mo>&lt;</mo></math></span> mg/h were consistently measured simultaneously. Thrust results concurred with indirect measurements with an average relative difference of 10.5%, showing a consistent ratio to the emitted current of <span><math><mrow><mo>≈</mo><mn>0</mn><mo>.</mo><mn>1</mn><mi>μ</mi></mrow></math></span>N/<span><math><mi>μ</mi></math></span>A. In contrast, the mass flow rate estimated from time-of-flight data was notably lower than the mass loss rate measured with the balance, with relative differences from −23.1% to −64.7%. Possible causes for this discrepancy and methods for their diagnosis are proposed.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 283-295"},"PeriodicalIF":3.1,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704792","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":"Rigid-flexible coupled dynamics and configuration stability of maneuverable space tether net under impact loads","authors":"Mani Kakavand,&nbsp;Zheng H. Zhu","doi":"10.1016/j.actaastro.2025.02.031","DOIUrl":"10.1016/j.actaastro.2025.02.031","url":null,"abstract":"<div><div>This paper investigates the configuration stability and rigid–flexible coupled dynamics of maneuverable space tether nets under impact loads. To analyze the complex 3D maneuvers of the net, a geometric mechanics framework is developed, incorporating the rigid–flexible coupling between wave propagation in the net and the attitude dynamics of maneuvering satellites attached to its corners. A coordinate-free representation in Lie group is derived for the satellites’ attitude dynamics on <span><math><mrow><mi>SO</mi><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></mrow></math></span>. Equilibrium states, modal shapes, and chaotic behavior of the tether net are examined using the geometric Jacobian method, which reveals the coexistence of stiff tether dynamics and slow satellite attitude motions, leading to extreme disparities in time scales and makes numerical analysis challenging by conventional integration schemes. To solve the problem, a structure-preserving integrator is derived to accurately analyze the chaotic behavior of the net over extended periods. Dynamic responses to impact loads are analyzed under two initial conditions: (i) a slack net and (ii) a net tensioned by satellite control forces and torques. Numerical results reveal significant coupling effects between net deformation and satellite attitude motion, and even minor perturbations may lead to chaotic responses of the net indicated by Lyapunov exponents. Moreover, the pre-tension of the net by control forces from satellites can effectively suppress chaotic behaviors, leading to more stable configuration and controlled maneuvering. These findings offer critical insights into configuration stability and dynamics of maneuverable space tether nets, which will enable the effective control strategy development to suppress chaos and enhance net’s maneuverability in three-dimensional space.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 114-131"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591511","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":"The Lorentz force-based control of a spacecraft formation flying using the harmonic charging law","authors":"M.A. Klyushin,&nbsp;A.A. Tikhonov","doi":"10.1016/j.actaastro.2025.02.047","DOIUrl":"10.1016/j.actaastro.2025.02.047","url":null,"abstract":"<div><div>In this paper, a spacecraft formation flying in the gravitational and magnetic fields of the Earth is investigated. The “direct magnetic dipole” is considered as a model of the geomagnetic field. A system of nonlinear differential equations describing the relative orbital motion of an electrically charged spacecraft is derived, as well as its simplified version. The analytical research of a spacecraft formation flying under the influence of the Lorentz force is carried out. The asymptotic solution of the differential system of the relative motion of a spacecraft with a variable electrical charge is found. The results of numerical modeling according to the derived system of nonlinear differential equations are presented. A comparison between the analytical and numerical solutions is made. The open-loop control algorithm, which is based on a charge change according to a simple harmonic law, is proposed to transfer a spacecraft to new relative orbits. The problem of programmed changing the distance between spacecraft is considered, which is carried out in three stages. The analytical trajectory is obtained, which agrees well with the results of numerical modeling using a nonlinear model.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 68-79"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580591","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":"FFS-CDPR: A free-floating simulator based on cable-driven parallel robots coordinating vibration from discontinuous external wrench","authors":"Guangyao Sun,&nbsp;Zhen Liu,&nbsp;Haibo Gao,&nbsp;Zongquan Deng","doi":"10.1016/j.actaastro.2025.02.036","DOIUrl":"10.1016/j.actaastro.2025.02.036","url":null,"abstract":"<div><div>The on-ground simulation of a free-floating operational environment is an essential part of the spacecraft dynamic validation. In the state-of-the-art, operational limits such as workspace limitation or limited time duration are a typical problem. As a consequence, we propose a redundant cable-driven parallel robot to reproduce a six-dimensional free-floating scenario. An efficient tension distribution algorithm based on computational geometry is exploited in real time. In addition, for cases where there are discontinuous external wrenches, e.g. docking, collision, a modified optimization method to produce the smallest possible step cable tension. The superiority of the optimization algorithm and the effectiveness of the CDPR-based free-floating movement simulation is verified through experiments.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 80-93"},"PeriodicalIF":3.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591508","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":"SatSORT: Online multi-spacecraft visual tracking algorithm","authors":"Yue Liu,&nbsp;Shijie Zhang,&nbsp;Huayi Li,&nbsp;Chao Zhang","doi":"10.1016/j.actaastro.2025.02.027","DOIUrl":"10.1016/j.actaastro.2025.02.027","url":null,"abstract":"<div><div>The deployment of large-scale constellations has led to a sharp increase in the number of spacecraft in orbit. To avoid collision risks and overcome the limitations of traditional single spacecraft tracking methods, this paper introduces a multi-spacecraft visual tracking method called SatSORT tailored to the specific requirements of the aerospace field. Based on the DeepSORT framework, the proposed method eliminates the appearance descriptor and introduces a matching strategy tailored for the identical spacecrafts. Furthermore, the data association has been improved to address the situations where targets are missed or occluded by each other. Enhancements have also been made to the Kalman filter to accommodate the varied visual motions of spacecraft and instances of missed detections. Extensive experimental results demonstrate that the new algorithm improves tracking performance impressively, reduces data association time by an order of magnitude, and maintains robust tracking capabilities under conditions of missed detections and occlusions.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 103-113"},"PeriodicalIF":3.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591510","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":"Gird-search-based neural network modeling of piezoelectric hysteresis for gravitational wave inertial sensor","authors":"Yanan Cheng ,&nbsp;Jinguo Liu ,&nbsp;Xin Zhang ,&nbsp;Bolin Lu","doi":"10.1016/j.actaastro.2025.02.042","DOIUrl":"10.1016/j.actaastro.2025.02.042","url":null,"abstract":"<div><div>The inertial sensor serves as the core payload for space-based gravitational wave detection, providing a stable inertial reference for observing mid-frequency and low-frequency gravitational waves in the universe and black holes. This paper designs a novel three-stage release mechanism for precisely releasing the test mass, namely the physical carrier of the inertial sensor. Due to the nonlinear hysteresis properties, modeling piezoelectric actuators plays an important role in ensuring low residual momentum. A neural network algorithm based on grid search-optimized multilayer perceptrons (MLP) is designed for the piezoelectric actuators used in the third-stage release mechanism. Meanwhile, an experimental setup is developed to acquire input and output data. The improved generalized Bouc-Wen (GB-W) and MLP models are used for parameter identification and model training. Experimental results indicate that the improved GB-W model achieves an error rate within 4%, while the MLP model optimized via grid search achieves a prediction error within 1%, demonstrating superior modeling performance. The MLP model offers a simpler yet more accurate approach, and its effective performance is verified through experiments with triangular and square wave signals across multiple frequencies.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 132-142"},"PeriodicalIF":3.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620367","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":"China's space station and international law-making","authors":"Luping Zhang","doi":"10.1016/j.actaastro.2025.03.002","DOIUrl":"10.1016/j.actaastro.2025.03.002","url":null,"abstract":"<div><div>In 2022, China finished building its own space station—Tiangong-marking a new age of space competition and cooperation. With the pace of retirement for the International Space Station, led by the United States and Russia, China's Space Station (CSS) could become a novel forum for future international cooperation. Against this backdrop, the importance of designing a legal framework, addressing key issues including but not limited to, registration, jurisdiction, liability, and dispute resolution surfaces. This article is among the first attempts to answer those questions.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 32-38"},"PeriodicalIF":3.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562847","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":"Influence of flame collisions with pressure waves on tulip flame formation and its evolution in tubes with non-slip walls","authors":"Chengeng Qian ,&nbsp;Mikhail A. Liberman","doi":"10.1016/j.actaastro.2025.03.001","DOIUrl":"10.1016/j.actaastro.2025.03.001","url":null,"abstract":"<div><div>The effects of flame collision with pressure waves during hydrogen/air flame propagation in a two-dimensional channel with non-slip adiabatic walls are studied for channels with different aspect ratios and a semi-open channel. The problem is solved by direct numerical simulations of the fully compressible Navier-Stokes equations coupled to a detailed chemical model for a stoichiometric hydrogen-air mixture using a high-order numerical code in space and time that provides adequate resolution of a flame and the flame-pressure wave interactions. It is shown that the flame–pressure wave interactions play an important role in the tulip flame formation and its further evolution to a distorted tulip flame (DTF). In particular, flame collisions with pressure waves reflected from the opposite end of the tube significantly enhance the effect of the first rarefaction wave generated by the decelerating flame in the unburned gas when the skirt of the “finger” flame touches the tube sidewalls. This is why the tulip-shaped flame is more pronounced in channels with both ends closed than in a semi-open tube. It is shown that the flame instabilities are not involved in the tulip flame formation, while the Rayleigh-Taylor instability caused by the flame collisions with the reflected pressure waves is the main factor in the DTF formation, in agreement with previous studies. We show that the wavelength of the fastest growing mode of the RT instability corresponds to the size of the bulges formed on the tulip flame lips.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 154-163"},"PeriodicalIF":3.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628144","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}