Acta Astronautica最新文献

{"title":"Multiple Mars gravity-assist trajectory to inclined Sun–Earth L4","authors":"Jinsung Lee ,&nbsp;Daniel J. Scheeres ,&nbsp;Sang-Hyun Lee ,&nbsp;Jaemyung Ahn","doi":"10.1016/j.actaastro.2025.05.010","DOIUrl":"10.1016/j.actaastro.2025.05.010","url":null,"abstract":"<div><div>The multiple Mars gravity-assist trajectory is compared to the phasing trajectory for placing a spacecraft in a circular Sun–Earth L4 orbit with a 1 AU semi-major axis and inclinations of 10° and <span><math><mrow><mn>14</mn><mo>.</mo><msup><mrow><mn>5</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> relative to the ecliptic plane. The gravity-assist maneuvers are treated as instantaneous velocity changes using a zero-sphere-of-influence model. The trajectory is optimized for two potential launch vehicles (Falcon 9 and Falcon Heavy) to achieve the desired orbit with minimal <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> energy. Through trajectory analysis based on various launch vehicles and their <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span>-based payload capacities, it was found that the multiple Mars gravity-assist trajectories are outperformed by the phasing trajectory at a 10° inclination but are additions to the Pareto optimal solutions for <span><math><mrow><mn>14</mn><mo>.</mo><msup><mrow><mn>5</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> inclination mission when considering the spacecraft’s arrival mass at the Sun–Earth L4.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 721-733"},"PeriodicalIF":3.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170036","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":"Applying the EVDT Systems Engineering Framework and satellite Earth Observation data for mapping SDG15 indicators in Ghana","authors":"Danielle Wood ,&nbsp;Temilola Fatoyinbo ,&nbsp;David Lagomasino ,&nbsp;Kofi Asare ,&nbsp;Charles Kofi Som ,&nbsp;Selaseh Akaho ,&nbsp;Caroline Doe ,&nbsp;Priscilla Baltezar ,&nbsp;Abigail Barenblitt ,&nbsp;Amanda Payton ,&nbsp;Daystar Babanawo ,&nbsp;Omar Seidu","doi":"10.1016/j.actaastro.2025.05.050","DOIUrl":"10.1016/j.actaastro.2025.05.050","url":null,"abstract":"<div><div>Satellite Earth Observation data can provide a resource to assist national statistical services as they compile data in support of reporting on the Sustainable Development Goal (SDG) Indicators via Voluntary National Reviews. Many national statistical services have traditionally relied on ground-based survey as the primary data collection approach. Several SDG Indicators, including SDG13 (Climate Action), SDG14 (Life Below Water) and SDG15 (Life on Land), can be facilitated by the use of satellite-based Earth Observation data. The process of adopting nontraditional data sources for SDG reporting requires collaboration among interdisciplinary teams with backgrounds in statistics, economics, remote sensing, geospatial data management and survey methods. The present study provides the experience of a collaborative team including leaders from the Ghana Statistical Service, the Ghana Space Science and Technology Institute and the a team of US-based scholars to apply satellite Earth Observation data for mapping several SDG15 Indicators. The work also includes a demonstration of methods for mapping changes in land cover and deforestation due to mining. The works shows that the adoption of a set of Systems Engineering Frameworks called Systems Architecture and EVDT (Environment-Vulnerability-Decision-Technology) facilitate the collaboration among experts from different backgrounds and provides a map for the translation of scientific analysis into policy-relevant findings. The methods use a combination of qualitative interviews, field visits, in-situ data collection, analysis of satellite Earth Observation data and software development. The findings demonstrate an upgraded capability adopted by the government of Ghana to support ongoing SDG Voluntary National Reporting.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 754-782"},"PeriodicalIF":3.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170039","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":"Corrected closed-form solutions to the Schweighart–Sedwick satellite relative motion model including differential drag","authors":"Constantin Traub,&nbsp;Jens Neubert,&nbsp;Luca Ingrillini","doi":"10.1016/j.actaastro.2025.05.019","DOIUrl":"10.1016/j.actaastro.2025.05.019","url":null,"abstract":"<div><div>Rendezvous maneuvers represent one of the most complex maneuvers in spaceflight. To approximate the relative motion between two objects during short time periods, linearized motion models, such as the well-known Clohessy-Wiltshire model, are commonly employed. To address the inaccuracy of these equations arising from the non-spherical gravitational potential field, Schweighart and Sedwick developed a linear relative motion model which accounts for the <span><math><msub><mrow><mi>J</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> effect. Closed-form solutions to these equations including differential specific forces between the two spacecrafts have been widely applied by multiple researchers to study the methodology of differential lift and drag.</div><div>While working with these solutions, however, it became apparent that small deviations between the numerically integrated and analytical solutions result if specific differential forces are applied in the tangential direction <span><math><mrow><mi>δ</mi><msub><mrow><mi>f</mi></mrow><mrow><mi>y</mi></mrow></msub></mrow></math></span>, which in the case of differential aerodynamic forces corresponds exactly to the main influence, namely differential drag. This insight was taken as an opportunity to determine corrected closed-form solutions via the computer algebra system <em>Maxima</em> (Maxima, 2023), a software package for performing computer algebra calculations. In this technical note, these solutions are presented, their correctness is demonstrated and subsequently the effect of the motion in the phase plane due to perturbing forces is discussed. This note is intended to contribute to the field of research by increasing the accuracy of future studies.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 742-753"},"PeriodicalIF":3.1,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170038","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":"The solar particle event at Mars on 2024 May 20: neutron component of the radiation environment","authors":"Igor Mitrofanov ,&nbsp;Maxim Litvak ,&nbsp;Anton Sanin ,&nbsp;Dmitry Golovin ,&nbsp;Sergey Nikiforov ,&nbsp;Maya Djachkova ,&nbsp;Artem Anikin ,&nbsp;Nikita Lukyanov ,&nbsp;Jordanka Semkova ,&nbsp;Yuri Matviichuk","doi":"10.1016/j.actaastro.2025.05.043","DOIUrl":"10.1016/j.actaastro.2025.05.043","url":null,"abstract":"<div><div>This paper presents the observational findings for the most powerful solar particle event (SPE) on Mars in the current 25th solar cycle, based on surface (DAN/Curiosity) and orbital (HEND/Mars Odyssey) measurements. The numerical modelling of SPE proton interaction with the atmosphere and Martian surface showed that the computational results are in good agreement with the experimental data. The neutron component of the radiation background in orbit and on the surface was evaluated near the SPE maximum. The integral neutron dose on the Martian surface during the entire SPE was estimated as 600 μSv, which equals the dose received during ∼11 days in quiet Sun environment. The obtained data were extrapolated to more powerful solar events known from the history of observation. The Carrington event was used as an example. For such a hypothetical SPE, the total neutron dose may achieve as high as 240 mSv. It is 1.6 times higher than annual dose limit allowed for astronauts in the NASA ORION project.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 734-741"},"PeriodicalIF":3.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170037","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":"Optimization of pump-valve combined regulation strategy for electric pump-fed system in a hybrid rocket motor","authors":"Hao Zhu ,&nbsp;Xintong Li ,&nbsp;Yuanjun Zhang ,&nbsp;Jincheng Wang ,&nbsp;Hui Tian ,&nbsp;Guobiao Cai","doi":"10.1016/j.actaastro.2025.05.046","DOIUrl":"10.1016/j.actaastro.2025.05.046","url":null,"abstract":"<div><div>Advances in motor and battery technologies have driven the implementation of electric pumps in propulsion systems. Hybrid rocket motors, distinguished by simplified thrust modulation capabilities, substantially improve spacecraft maneuverability. The thrust regulation capacity can be enhanced through electric pump-fed systems that enable rapid, large-scale thrust adjustments. This study presents the design of a hydrogen peroxide electric pump-fed system for variable-thrust hybrid rocket motors. However, the system demonstrates significant parameter variations and encounters unsteady dynamic processes. During rapid parameter fluctuations, multiple subsystems demonstrate stiffness characteristics leading to numerical instability in solutions. Achieving accurate dynamic simulations while optimizing stable start-up processes and wide-range thrust regulation remains a critical challenge. In this research, simulation models of the basic components and the overall hydrogen peroxide electric pump-fed system were developed, with experimental validation performed through cold flow tests. Comparative analysis revealed less than 2 % deviation between experimental and simulated key parameters, confirming model validity. Building on validated multi-disciplinary models, an integrated optimization framework was established featuring: high-fidelity system modeling, efficient surrogate model development, multi-objective optimization, and multi-criteria evaluation for pump-valve coordinated control during start-up and thrust adjustment phases. Results indicate the multilayer perceptron-based optimization strategy decreases high-frequency current pulses by 27 % during start-up and reduces energy consumption by 5.4 % during thrust adjustment compared to conventional linear methods. These improvements significantly enhance system efficiency and operational safety. This work establishes a methodological framework for electric pump-fed system design and advances hybrid propulsion technology development.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 795-806"},"PeriodicalIF":3.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168240","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":"Nondeterministic polynomial time algorithm for estimation of space launch base launch capacity","authors":"Michal Kurela ,&nbsp;Olivier Nogues ,&nbsp;Jean-Frédéric Alasa","doi":"10.1016/j.actaastro.2025.05.041","DOIUrl":"10.1016/j.actaastro.2025.05.041","url":null,"abstract":"<div><div>When designing the new space launch bases their maximum launch capacity must be defined. The deterministic evaluation of the launch rate can be performed when the entry hypotheses are very simple. However, when increasing the number of constraints there are no deterministic methods to account for all complexity of launch rate scheduling. That is why we consider it as an NP (nondeterministic polynomial time) problem. The specific algorithm had been developed with an objective to place the maximum number of launch campaigns in a calendar year with numerous constraints, such as launch range, launch operators' concepts of operations (CONOPS), as well as any kind of probability distribution function. Applying the constructed model and varying its parameters, the probability distribution functions of spaceport launch capacity had been obtained over thousands of simulations. The algorithm's behavior had been characterized through test cases. The polyvalent simulation capacity of the algorithm provided the insight to the intrinsic problems and limitations of the spaceport with very high launch rates. In addition, it allowed simulating the potential solutions in terms of spaceport organization, contractual rules towards users and suggest the technical facilities to maximize the available launch capacity.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 783-794"},"PeriodicalIF":3.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170040","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":"Modified smoothing-homotopy-based sequential convex programming for ascent trajectory optimization with path constraints","authors":"Mengxin Zhao ,&nbsp;Binfeng Pan ,&nbsp;Shan Lu ,&nbsp;Xiyu Hou","doi":"10.1016/j.actaastro.2025.04.058","DOIUrl":"10.1016/j.actaastro.2025.04.058","url":null,"abstract":"<div><div>To meet the growing demands for reliability and onboard performance in launch missions, this paper introduces a modified smoothing-homotopy sequential convex programming (MSH-SCP) approach for endo-atmospheric ascent trajectory optimization problems with strict path constraints. Compared to the original SH-SCP, the proposed method introduces three major enhancements. Firstly, the convolution of the smoothing kernel is extended from the terminal state to all discrete states across the entire time domain. This alleviates the challenges posed by non-convexity in highly nonlinear ascent problems, resulting in an easier and more tractable smoothed problem. Secondly, by replacing states in path constraints with smoothed states, this method eliminates the need to transform path constraints into control constraints, allowing state constraints to be handled directly. Lastly, the continuous-time problem is discretized into a sequence of finite-dimensional sub-problems by parameterizing state and control variables using non-uniform rational basis spline (NURBS) curves. Leveraging from the superior fitting characteristics and strong convex hull properties of NURBS curves, optimization variables and constraints are reduced in number, markedly enhancing computational speed. Numerical simulations reveal that the MSH-SCP method achieves superior convergence behavior and exhibits significant improvements in computational efficiency.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 632-643"},"PeriodicalIF":3.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131409","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":"Analysis of the unsteady shock wave motion in inlet unstart processes","authors":"Carlos Carbajosa,&nbsp;Ángel Sanz-Andrés,&nbsp;Alejandro Martínez-Cava,&nbsp;Mikel Ogueta-Gutiérrez","doi":"10.1016/j.actaastro.2025.05.006","DOIUrl":"10.1016/j.actaastro.2025.05.006","url":null,"abstract":"<div><div>This paper is focused on the shock wave motion during inlet starting and unstarting phenomena (swallowing and expelling of shock waves) on supersonic and hypersonic diffusers, which are critical for the efficient operation of both ramjets and scramjets. The motion speed of a normal shock wave along the inlet duct during these processes is analyzed to better understand the influence of design parameters, such as the Mach number (<span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>∞</mi></mrow></msub></math></span>) and contraction ratio (<span><math><mrow><mi>C</mi><mi>R</mi></mrow></math></span>), on the speed and stability behavior of the shock wave position.</div><div>A one-dimensional (1D) quasi-steady mathematical model is presented here, labeled <span><math><mrow><mi>D</mi><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>M</mi></mrow></math></span> (<em>Duct Shock Speed Model</em>), which allows for fast approximate calculations. This simple approach is useful for analyzing how the shock wave motion speed changes along the duct as a function of the duct geometry and operating parameters. It also allows for shock wave position stability assessment around equilibrium positions. This model is also suitable for hypersonic configurations, where the set of shock waves that appears, so-called pseudo-shock, could be appropriately replaced by an equivalent normal shock, subjected to a corrected Mach number, lower than that of the original system.</div><div>In the presentation of results, both stable and unstable cases are discussed, showing how the shock wave can be swallowed or expelled depending on the evolution of the flow and duct geometry. Finally, the results obtained from the <span><math><mrow><mi>D</mi><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>M</mi></mrow></math></span> model developed here are compared with relevant published experimental data (including shock unstart experiments on two-dimensional and three-dimensional inlets with and without combustion, as well as buzz analysis in a scramjet), showing a good agreement. Difficulties concerning the comparison exercises are outlined.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 601-618"},"PeriodicalIF":3.1,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116993","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":"The influence of confined channel configuration on the detonation waves induced by hot jet under supersonic pulsating flow","authors":"Jin Nanxi ,&nbsp;Kong Fanchao ,&nbsp;Dai Jian","doi":"10.1016/j.actaastro.2025.05.022","DOIUrl":"10.1016/j.actaastro.2025.05.022","url":null,"abstract":"<div><div>The detonation engine combustion chamber represents a typical confined channel, whose operational stability is significantly influenced by the coupling effects between complex inlet shock structures and combustion chamber backpressure fluctuations. Based on supersonic pulsating inflow simulating practical conditions, this work delves into detonation propagation characteristics and mechanisms through examining three confined channel configurations: rectangular channel, expanding channel, and cavity-coupled expanding channel. Numerical calculations are performed using a hybrid sixth-order weighted essentially non-oscillatory centered difference scheme and a one-step, two-species hydrogen-oxygen finite-rate chemistry model. The results reveal that, compared to the rectangular channel, the expanding channel exhibits enhanced disturbances, generating separated oblique shock waves. These shock waves reduce the detonation wave length and stability, leading to severe attenuation in later stages. In the cavity-coupled expanding combustion chamber, pressure oscillation waves advance the initiation time and increase both propagation time and distance, thereby enhancing detonation stability through intensified shock reflections and unburned gas mixing. Notably, increasing the cavity length strengthens the pressure oscillation waves and widens the subsonic channel ahead of the cavity. However, when the length-to-depth ratio exceeds 2.5, flow field instability induced by bifurcated unburned jets is identified as causing abnormal detonation wave recession. Therefore, optimizing the length-to-depth ratio to 2.0–2.5 achieves a balance between stability and structural compactness, maximizing performance benefits. The findings support optimized combustion chamber designs for detonation-based propulsion systems.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 575-587"},"PeriodicalIF":3.1,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107489","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":"‘Sub-orbital activities’ – the application of ‘international law’ in the twilight between air and space law","authors":"Irmgard Marboe","doi":"10.1016/j.actaastro.2025.05.037","DOIUrl":"10.1016/j.actaastro.2025.05.037","url":null,"abstract":"<div><div>‘Sub-orbital activities’ – also referred to as ‘high altitude activities’, ‘higher airspace operations’ or ‘non-orbital spaceflight activities’ – are difficult to grasp from a legal perspective. Are they ‘aviation activities’ – governed by national and international air law – or are they ‘space activities’ – governed by national and international space law? The Space Law Committee of the International Law Association (ILA) has worked on this topic for more than a decade and finally adopted ‘Rules on Non-Orbital Spaceflight Activities’ at its 2024 Biennial Conference in Athens. One of the issues discussed was whether and to what extent ‘international law’ should be applicable to such activities. The present paper re-capitulates arguments in favor and against this idea and sheds some light upon relevant legal issues, such as state responsibility and liability, as well as on the role of commercial actors, in the twilight between air law and space law.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"234 ","pages":"Pages 807-810"},"PeriodicalIF":3.1,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168241","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}