Acta AstronauticaPub Date : 2025-03-08DOI: 10.1016/j.actaastro.2025.02.051
Qiyou Liu , Penghui Li , Hu Sun , Dingwei Zhang , Bingqiang Ji , Lijun Yang , Qingfei Fu
{"title":"Spray characteristics of gel containing nanoparticles in impinging jet injectors","authors":"Qiyou Liu , Penghui Li , Hu Sun , Dingwei Zhang , Bingqiang Ji , Lijun Yang , 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}
Acta AstronauticaPub Date : 2025-03-07DOI: 10.1016/j.actaastro.2025.02.031
Mani Kakavand, Zheng H. Zhu
{"title":"Rigid-flexible coupled dynamics and configuration stability of maneuverable space tether net under impact loads","authors":"Mani Kakavand, 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}
Acta AstronauticaPub Date : 2025-03-07DOI: 10.1016/j.actaastro.2025.02.047
M.A. Klyushin, A.A. Tikhonov
{"title":"The Lorentz force-based control of a spacecraft formation flying using the harmonic charging law","authors":"M.A. Klyushin, 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}
Acta AstronauticaPub Date : 2025-03-06DOI: 10.1016/j.actaastro.2025.02.036
Guangyao Sun, Zhen Liu, Haibo Gao, Zongquan Deng
{"title":"FFS-CDPR: A free-floating simulator based on cable-driven parallel robots coordinating vibration from discontinuous external wrench","authors":"Guangyao Sun, Zhen Liu, Haibo Gao, 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}
Acta AstronauticaPub Date : 2025-03-06DOI: 10.1016/j.actaastro.2025.02.027
Yue Liu, Shijie Zhang, Huayi Li, Chao Zhang
{"title":"SatSORT: Online multi-spacecraft visual tracking algorithm","authors":"Yue Liu, Shijie Zhang, Huayi Li, 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}
Acta AstronauticaPub Date : 2025-03-05DOI: 10.1016/j.actaastro.2025.03.002
Luping Zhang
{"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}
Acta AstronauticaPub Date : 2025-03-03DOI: 10.1016/j.actaastro.2025.02.037
Carmelo Magnafico, Umberto De Filippis, Francesco Santoli, Carlo Lefevre, Marco Lucente, David Lucchesi, Emiliano Fiorenza, Roberto Peron, Valerio Iafolla
{"title":"Italian Spring Accelerometer measurements of unexpected Non Gravitational Perturbation during BepiColombo second Venus swing-by","authors":"Carmelo Magnafico, Umberto De Filippis, Francesco Santoli, Carlo Lefevre, Marco Lucente, David Lucchesi, Emiliano Fiorenza, Roberto Peron, Valerio Iafolla","doi":"10.1016/j.actaastro.2025.02.037","DOIUrl":"10.1016/j.actaastro.2025.02.037","url":null,"abstract":"<div><div>The Italian Spring Accelerometer (ISA) is a three axis mass–spring accelerometer, one of the payloads of the BepiColombo joint space mission between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). At launch in October 2018, BepiColombo started its seven-year cruise as a stack of three different modules, overall named Mercury Composite Spacecraft (MCS). The spacecraft will provide BepiColombo the necessary Delta V to reach Mercury with its electric thrusters and along with one, two and six gravity assists, respectively with Earth, Venus and Mercury. The accelerometer is accommodated on the Mercury Planetary Orbiter (MPO) module and, jointly with the Ka-band Transponder (KaT) tracking data, will primarily serve the BepiColombo Radio Science Experiment (BC-RSE). During the second Venus swing-by, strong tidal effect and external perturbations was expected to act on the spacecraft and to become detectable by ISA. The swing-by had a closest approach of about 550 km and the gravity gradient on the IDA sensing elements was measured as expected. Hence, in this paper, the first direct gravity gradients effect detection generated by an extraterrestrial body is shown. Nevertheless, around the closest approach, the measurements evidenced a spurious acceleration event lasting for several minutes. This work, exploiting information on the Attitude and Orbit Control System (AOCS) commanded torques, focuses and analyses this ISA acceleration signal, ascribing it to a net force really acting on the MCS spacecraft. Furthermore, using an estimation method, the application point of the force is identified within an area close to the MPO radiator.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 14-22"},"PeriodicalIF":3.1,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548725","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}
Acta AstronauticaPub Date : 2025-03-01DOI: 10.1016/j.actaastro.2025.02.049
Dingwei Zhang , Boqi Jia , Yue Zhang , Hu Sun , Qiyou Liu , Bingqiang Ji , Lijun Yang , Qingfei Fu
{"title":"Atomization of gel propellants using a Hartmann whistle injector","authors":"Dingwei Zhang , Boqi Jia , Yue Zhang , Hu Sun , Qiyou Liu , Bingqiang Ji , Lijun Yang , Qingfei Fu","doi":"10.1016/j.actaastro.2025.02.049","DOIUrl":"10.1016/j.actaastro.2025.02.049","url":null,"abstract":"<div><div>Gel propellants, which combine the benefits of solid and liquid propellants, suffer from poor atomization quality due to their high viscosity. Sonic atomization technology has demonstrated potential in atomizing high-viscosity non-Newtonian fluids. This study designed a Hartmann whistle injector comprising a central gas path, an annular slit liquid path, and a resonant cavity. Schlieren imaging and the microphone measurements revealed that the sound waves originate at the leading edge of the resonant cavity, with an optimal gas path pressure identified for generating the strongest acoustic field. A water-based simulant with rheological properties similar to gel propellants was employed for atomization experiments. High-speed imaging demonstrated that the Hartmann whistle injector significantly enhanced gel liquid breakup, reducing the Sauter Mean Diameter (SMD) by up to 37 % compared to the conventional gas-liquid coaxial injector. Orthogonal experiments investigated the effects of liquid annular slit width, central rod diameter, resonant cavity distance, and gas pressure on atomization performance, revealing optimal parameter combinations. These findings highlight the potential of Hartmann whistle injectors for advancing gel propulsion technologies.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 39-50"},"PeriodicalIF":3.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580589","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}
Acta AstronauticaPub Date : 2025-02-28DOI: 10.1016/j.actaastro.2025.02.045
Dan M. Goebel , Adele R. Payman , Giulia Becatti , Jacob Simmonds
{"title":"Heaterless LaB6 lollipop hollow cathode for center-mounting in Hall thrusters","authors":"Dan M. Goebel , Adele R. Payman , Giulia Becatti , Jacob Simmonds","doi":"10.1016/j.actaastro.2025.02.045","DOIUrl":"10.1016/j.actaastro.2025.02.045","url":null,"abstract":"<div><div>Hollow cathodes are a critical component of Hall thrusters, providing electrons for both plasma generation and beam neutralization. A new 10-kW-class thruster, named the H10, has been developed at JPL and demonstrated >3000 s Isp and over 70 % efficiency in steady state operation at up to 15 kW. The cathode for the H10 thruster is a heaterless lanthanum hexaboride (LaB<sub>6</sub>) hollow cathode designed in a “lollipop” configuration and center-mounted in the Hall thruster. This shape features a short, compact cathode body that contains the LaB<sub>6</sub> thermionic insert, graphite keeper and alumina insulators. The cathode assembly then necks down to a small diameter gas feed tube that acts as the cathode electrical conductor, and a separately insulated keeper lead. This geometry is ideally suited for magnetically shielded Hall thrusters because it minimizes the amount of magnetic material that must be removed from the inner magnetic core to fit in the centrally-mounted cathode, thus enabling higher magnetic fields by reducing saturation of the inner core. The heaterless cathode starts in only 3 min using less than 100 W of keeper discharge power, and has demonstrated operation in the thruster at discharge currents of 2–50 A. The design, performance and life of the cathode and heater are described.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 193-199"},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550607","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}
Acta AstronauticaPub Date : 2025-02-28DOI: 10.1016/j.actaastro.2025.02.030
Joel Patzwald , Rafael Kleba-Ehrhardt , Ferry Schiperski , Tjorben Griemsmann , Stefan Linke , Thomas Neumann , Ludger Overmeyer , Enrico Stoll , David Karl
{"title":"Properties of novel LX lunar regolith simulant system — The base simulants: Part 1","authors":"Joel Patzwald , Rafael Kleba-Ehrhardt , Ferry Schiperski , Tjorben Griemsmann , Stefan Linke , Thomas Neumann , Ludger Overmeyer , Enrico Stoll , David Karl","doi":"10.1016/j.actaastro.2025.02.030","DOIUrl":"10.1016/j.actaastro.2025.02.030","url":null,"abstract":"<div><div>The renewed interest in lunar exploration has increased research efforts in lunar in-situ resource utilisation (ISRU), which involves using locally sourced materials to reduce reliance on expensive and complex Earth-based logistics. Lunar regolith, a loose layer of fragmented rock covering the Moon’s surface, often many metres thick, is the primary ISRU material due to its abundance and accessibility. It can, for example, be used to construct infrastructure, extract consumables, and produce secondary goods. Lunar regolith analogue materials (simulants) are fundamental for developing and testing such ISRU technologies in laboratories on Earth before they are applied to other celestial bodies. The composition of the regolith on the lunar surface varies greatly in terms of its mineralogical, chemical, and particle type composition. Current simulants fail to adequately replicate this variability. Therefore this study introduces a flexible simulant system capable of tailoring simulants to different applications. The lithic base simulants LX-T100 (anorthosite) and LX-M100 (basalt) represent the Moon’s two major bedrock types and serve as the foundation for this system. In this study, these base simulants are comprehensively characterised in terms of their mineralogy using XRD, chemistry using XRF, particle size distribution by dry and wet sieving, laser scattering, and dynamic image analysis, particle morphology via image analyses, maximum, minimum, bulk, and solid density using a tapped volumeter, Scott volumeter, bulk density funnel, and pycnometer, respectively, and from these the void ratio and porosity are calculated. It is shown that the base simulants are good analogue materials for lunar soil. In Europe, in particular, the LX simulants aim to address the poor availability of suitable simulants.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 200-222"},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550604","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}