Acta Astronautica最新文献

{"title":"A comprehensive transient fluid-solid coupled numerical model for hybrid rocket nozzle erosion and its experimental validation","authors":"Xiaoting Niu ,&nbsp;Hui Tian ,&nbsp;Xianzhu Jiang ,&nbsp;Yudong Lu ,&nbsp;Ruikai Chen ,&nbsp;Jingfei Gao ,&nbsp;Guobiao Cai","doi":"10.1016/j.actaastro.2025.02.014","DOIUrl":"10.1016/j.actaastro.2025.02.014","url":null,"abstract":"<div><div>The nozzle ablation of the hybrid rocket is a complex multi-physics coupling phenomenon that significantly influences the performance of the rocket. However, the coupling process for the various physics fields during the nozzle erosion problem remains unclear. To tackle this problem, a comprehensive hybrid rocket nozzle erosion numerical model that integrates the fuel regression process, the altering flame structure, the varying nozzle internal surface morphology, and the transient nozzle material heat transfer process is proposed in this work. Transient simulation is performed on the fluid-solid coupling physics field of the hybrid rocket adopting the dynamic mesh technique to depict the fuel regression and the nozzle erosion. Meanwhile, the nozzle erosion rate is obtained via the solid-fluid coupling heat transfer process and the thermal chemical erosion process. To validate the model proposed, a 20-s firing test is conducted on the 95 % H₂O₂/polyethylene propellant hybrid rocket adopting needle-punched structure carbon-ceramic material throat. The consistency between the simulation and experiment combustion chamber pressure, thrust, nozzle outer surface temperature, and throat radius increment further supports the effectiveness of the model proposed. Simulation results reveal that the heat flux peak in the nozzle internal surface decreased from 18 MW/m² to 2 MW/m² at a declining rate. The maximum erosion rate is observed in the latter of the converging segment and the front of the straight segment. Meanwhile, the uneven axial distribution of the erosion rate further leads to protrusion generation at the entrance of the straight segment of the throat, which further influences the local flow field, heat flux, and erosion rate. Overall, the erosion rate at the throat gradually increases over time and declines as the coordinates move downstream in the nozzle straight section.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 16-29"},"PeriodicalIF":3.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421020","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 comprehensive assessment of rocket body related space debris and discussion of suitable means of risk reduction","authors":"Sophie Förste,&nbsp;Leila El Yousfi,&nbsp;Jan-Steffen Fischer,&nbsp;Fabrizio Turco,&nbsp;Constantin Traub,&nbsp;Stefanos Fasoulas","doi":"10.1016/j.actaastro.2025.01.068","DOIUrl":"10.1016/j.actaastro.2025.01.068","url":null,"abstract":"<div><div>Rocket bodies account for about 50<!--> <!-->% of the total debris mass currently orbiting the Earth. They contribute significantly to the consistent growth in space debris due to their high collision and fragmentation risk and represent a high on-ground risk in the event of an uncontrolled re-entry. As a compensatory measure, orbital rocket stages are to descend over the ocean by means of an active deorbit manoeuvre so that unburned parts no longer pose an acute danger. However, mitigating the negative environmental impacts of destructive atmospheric re-entry is becoming more of a priority due to the increasing space activities and growing knowledge about re-entry emissions. Hence, a non-destructive, controlled re-entry might be a possible alternative for large objects, which requires a “Design not to Demise” (Dnot2D). To evaluate the applicability of Dnot2D to rocket bodies, it is necessary to obtain a comprehensive understanding of their physical characteristics, the distribution of different vehicle types, and the quantities of relevant objects involved. Within this study, an in-depth evaluation of documented rocket body related space debris objects with a focus on their orbit, mitigation timelines, mass, and geometry, utilizing publicly available databases, is presented. Special attention is given to active systems as potential targets for mitigation measures with regard to environmental impact. Additionally, a parametric trajectory analysis is conducted to quantify the influence of key parameters relevant for Dnot2D, employing empirical methods. Finally, concrete measures for implementing a Dnot2D are discussed based on the results.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 54-64"},"PeriodicalIF":3.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421002","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 pintle injector with high gas-liquid momentum ratio","authors":"Jiaqi Li ,&nbsp;Nanjia Yu ,&nbsp;Shutao Han ,&nbsp;Chuang Zhou ,&nbsp;Bowei Jiao","doi":"10.1016/j.actaastro.2025.02.012","DOIUrl":"10.1016/j.actaastro.2025.02.012","url":null,"abstract":"<div><div>Experimental and numerical simulation methods were employed to investigate the spray characteristics of a pintle injector under high gas-liquid momentum ratio conditions. In the experiments, water and nitrogen were used as the working media. The spray angle and spray modes were investigated using background light imaging and dynamic mode decomposition techniques. Numerical simulations were carried out using a three-dimensional Volume of Fluid to Discrete Particle Model (VOF to DPM) to explore the spray field configuration, Sauter Mean Diameter (SMD) of droplets, and droplet distribution. The results indicate that the spray pattern of the high momentum ratio gas-liquid pintle injector is distinct from that of the traditional hollow cone, presenting as a solid cylindrical spray with reduced size and lower turbulence levels in the recirculation zone. An empirical formula was derived for the spray angle, expressed as <span><math><mrow><mi>θ</mi><mo>=</mo><mn>32</mn><msup><mrow><mo>(</mo><mfrac><mi>M</mi><msqrt><mtext>We</mtext></msqrt></mfrac><mo>)</mo></mrow><mrow><mo>−</mo><mn>0.63</mn></mrow></msup></mrow></math></span>, incorporating the Weber number as a significant factor influencing the spray angle. Furthermore, the spray modes were classified into three types based on the gas-liquid momentum ratio (M) and Weber number (We), and their oscillation patterns were analyzed individually. The <em>M</em> was found to significantly influence the droplet diameter and distribution: a higher ratio resulted in a smaller droplet size but also led to droplet accumulation below the injector's central axis, potentially compromising the thermal protection of the pintle tip.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 119-130"},"PeriodicalIF":3.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454581","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":"Design and optimization of self-sensing voice coil actuator for spacecraft micro-vibration isolation","authors":"Qian Zhang ,&nbsp;Bingtao Li ,&nbsp;Guoying Zhao ,&nbsp;Huihui Miao ,&nbsp;Chenxi Wang ,&nbsp;Naijin Liu ,&nbsp;Jinxin Liu","doi":"10.1016/j.actaastro.2025.02.011","DOIUrl":"10.1016/j.actaastro.2025.02.011","url":null,"abstract":"<div><div>With the development of spacecraft towards flexibility and complexity, vibration isolators with compact structure, low natural frequency, and high output force have become more and more significant. In this paper, a self-sensing voice coil actuator (SSVCA) with a high output force constant and low natural frequency is proposed for the micro-vibration isolation of the reaction wheel. The overall structure of the SSVCA with low axial stiffness and self-sensing capability is presented first. Then, a magnetic circuit modeling method based on an equivalent current model (MCM-ECM) is proposed, which can be easily embedded into an optimization algorithm for magnetic circuit optimization. The numerical simulation indicates that the proposed method can improve the output force constant of the SSVCA by 14.79 %, compared with the FEM based on the parametric analysis. Finally, experimental verification of the SSVCA is conducted, and the results indicate that (1) the output force constant error between the experiment and the proposed MCM-ECM is 0.78 % (experimental value is 9.13 N/A and MCM-ECM value is 9.05 N/A); (2) the acceleration collected by the self-sensing coil is consistent with the standard accelerometer under different frequencies, with a mean error of 0.0125 g, and the mean square error (MSE) is 0.0064 g; (3) the natural frequency of the SSVCA with 6.2 kg payload mass obtained by sine sweep frequency experiment is 5.335 Hz. The SSVCA used for passive isolation can achieve vibration attenuation of over −30 dB, while active isolation can achieve vibration attenuation of over −50 dB in the frequency range of 3.67–150 Hz, verifying its good low-frequency vibration isolation performance.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"229 ","pages":"Pages 901-917"},"PeriodicalIF":3.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the feasibility of spherical magnetic liquid mirror telescopes","authors":"Eric A. Comstock,&nbsp;Hugh Chen,&nbsp;Tianyang Hu,&nbsp;Álvaro Romero-Calvo","doi":"10.1016/j.actaastro.2025.01.066","DOIUrl":"10.1016/j.actaastro.2025.01.066","url":null,"abstract":"<div><div>Liquid mirror telescopes exploit the rotation of a reflective fluid to generate diffraction-limited parabolic surfaces. They are economical and scalable but limited to zenith pointing. To expand their field of view, liquid mirror surfaces may be actuated into a spherical cap by means of magnetically susceptible liquids and electromagnetic coils, allowing the optics to rotate without actuating the mirror. However, the practical implementation of the concept remains largely unexplored. This paper adopts a nonlinear ferrohydrodynamic model to explore the technical feasibility of spherical liquid mirror telescopes. Surface deviations for a limited number of coils are extrapolated to determine the magnetic configuration requirements for a given optical wavelength, leading to an expected necessary coil count of <span><math><mrow><mn>16</mn><mo>±</mo><mn>12</mn></mrow></math></span> for a mirror capable of operation in the visible spectrum, and <span><math><mrow><mn>13</mn><mo>±</mo><mn>10</mn></mrow></math></span> for one operating in the mid-infrared. Tolerances of <span><math><mrow><mn>7</mn><mo>.</mo><mn>3</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> for coil positioning, 6.0 A for coil currents, and 9.1 nrad s⁻¹ for mirror spinning speed are required with coil currents of up to 20 MA to achieve the optical performance metrics using low-density ferrofluids. The results indicate that, although mathematically achievable, the required precision exceeds current technological capabilities, motivating alternative approaches to the problem.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 30-38"},"PeriodicalIF":3.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420450","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 station keeping of satellites in areostationary Mars orbit: A predictive control approach","authors":"Robert D. Halverson ,&nbsp;Avishai Weiss ,&nbsp;Gabriel Lundin ,&nbsp;Ryan J. Caverly","doi":"10.1016/j.actaastro.2025.01.064","DOIUrl":"10.1016/j.actaastro.2025.01.064","url":null,"abstract":"<div><div>The continued exploration of Mars will require a greater number of in-space assets to aid interplanetary communications. Future missions to the surface of Mars may be augmented with stationary satellites that remain overhead at all times as a means of sending data back to Earth from fixed antennae on the surface. These areostationary satellites will experience several important disturbances that push and pull the spacecraft off of its desired orbit. Thus, a station-keeping control strategy must be put into place to ensure the satellite remains overhead while minimizing the fuel required to elongate mission lifetime. This paper develops a model predictive control policy for areostationary station keeping that exploits knowledge of non-Keplerian perturbations in order to minimize the required annual station-keeping <span><math><mrow><mi>Δ</mi><mi>v</mi></mrow></math></span>. The station-keeping policy is applied to a satellite placed at various longitudes, and simulations are performed for an example mission at a longitude of a potential future crewed landing site. Through careful tuning of the controller constraints, and proper placement of the satellite at stable longitudes, the annual station-keeping <span><math><mrow><mi>Δ</mi><mi>v</mi></mrow></math></span> can be reduced relative to a naïve mission design.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 1-15"},"PeriodicalIF":3.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387170","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":"Balancing commercialization and sustainability in outer space: Addressing new challenges","authors":"Anish Dey,&nbsp;Jithin Jagadanandan","doi":"10.1016/j.actaastro.2025.02.010","DOIUrl":"10.1016/j.actaastro.2025.02.010","url":null,"abstract":"<div><div>One notable aspect of NewSpace is the growing influence of private non-state actors. Nation-states have also implemented policies that facilitate the involvement of private non-state players in space activities. The lack of progress in international space law since the Moon Agreement of 1979 highlights the need to reconsider and update the existing legal system. Therefore, it is necessary to create a different framework based on the concept of commercial reality. The article emphasises the impact of NewSpace on the technological and commercial aspects of the outer space industry. An analysis is conducted on the crucial requirement for regulatory reform in the field of outer space law and policy, which arises from these advancements in the future. The persistent obstacle in addressing the commercial development of NewSpace is the lack of clarity surrounding property rights in outer space, particularly concerning the ownership and utilisation of space resources. This article examines the issue presented by the national space laws, which have conflicting and inconsistent views on property rights in outer space. The article also aims to investigate the practicality of establishing an international framework for space cooperation. The importance of the New Age institutional mechanism for international collaboration and the agenda for the proposed mechanism are emphasized. The proposed institutional framework aims to achieve a balance between commercialization and profit-driven market pressures, considering their potential negative effects on the sustainable usage of outer space. In conclusion, the article discusses India's appropriate course of action in response to the emerging problems in the field of space exploration.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"229 ","pages":"Pages 895-900"},"PeriodicalIF":3.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387162","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":"Joint observation and transmission scheduling of multiple agile satellites with energy constraint using improved ACO algorithm","authors":"Minghao Shang ,&nbsp;Ronggang Yuan ,&nbsp;Bin Song ,&nbsp;Xuxing Huang ,&nbsp;Bin Yang ,&nbsp;Shuang Li","doi":"10.1016/j.actaastro.2025.02.008","DOIUrl":"10.1016/j.actaastro.2025.02.008","url":null,"abstract":"<div><div>The problem of joint observation and transmission scheduling with energy constraint is very important, but has received limited attention so far. To address the joint scheduling problem considering energy consumption and supplement, a new constraint satisfaction model with energy constraint for multiple agile satellites is established. Then a Local Search Enhanced Ant Colony Optimization with Multi-Knapsack Task Assignment (LSE-ACO-MKTA) algorithm is proposed, integrating observation, transmission, and charging into a unified planning framework. The algorithm employs a multi-knapsack-based task assignment strategy and local search enhanced ACO algorithm, significantly reducing the dimension of the original problem. The first simulation experiment validated the necessity of joint scheduling with energy constraint. After that, two comparative experiments were conducted to discuss the mechanism of local search and task assignment and then proved the efficiency of LSE-ACO-MKTA.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 92-103"},"PeriodicalIF":3.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446148","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":"Thermal stability of hafnia-containing ceramics for high temperature coatings","authors":"Valentina L. Stolyarova ,&nbsp;Viktor A. Vorozhtcov","doi":"10.1016/j.actaastro.2025.02.007","DOIUrl":"10.1016/j.actaastro.2025.02.007","url":null,"abstract":"<div><div>Ceramics containing oxides of hafnium, zirconium, and rare earth metals can be considered as a base for development of thermal protection systems, which are in urgent demand for use at high temperature operation of aircraft and space vehicles. However, limited information on evaporation processes greatly limits the prospects of their applications as the operation temperatures are increasing. In this investigation, the information about the processes of evaporation and thermodynamic data determined by Knudsen effusion mass spectrometry in binary, ternary, and quaternary compositions based on oxides of hafnium, zirconium, and rare earth metals, which can be regarded as really important for such consideration, is discussed. A systematic comparison of rates of evaporation of samples in Sm₂O₃-Y₂O₃-ZrO₂-HfO₂, La₂O₃-Y₂O₃-ZrO₂-HfO₂, La₂O₃-Sm₂O₃-Y₂O₃-HfO₂, La₂O₃-Sm₂O₃-ZrO₂-HfO₂, Gd₂O₃-Y₂O₃-HfO₂, and Gd₂O₃-ZrO₂-HfO₂ systems at 2373 K is presented. The main factors influencing the evaporation rates of the hafnia- and zirconia-based ceramics are determined, including the chemical nature of the oxides, their content, temperature, and existence of the condensed phase compounds. The data of this investigation are of exceptional significance in preparation of the refractory systems, for example using physical vapor deposition, as well as the development of protective coating with unique physicochemical properties, which are valuable for application at high temperatures up to 3000 K.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"229 ","pages":"Pages 866-873"},"PeriodicalIF":3.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378865","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":"Interpersonal dynamics in spaceflight: An archival study","authors":"Tripp Driskell ,&nbsp;C. Shawn Burke ,&nbsp;James E. Driskell","doi":"10.1016/j.actaastro.2025.01.065","DOIUrl":"10.1016/j.actaastro.2025.01.065","url":null,"abstract":"","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"229 ","pages":"Pages 861-865"},"PeriodicalIF":3.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372200","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}