Pub Date : 2026-04-01Epub Date: 2026-01-03DOI: 10.1016/j.actaastro.2025.12.055
Alejandro Macario-Rojas , Dale M. Weigt , L. Alberto Cañizares , Shane A. Maloney , Sophie A. Murray , Peter T. Gallagher , Nicholas H. Crisp , Ciara N. McGrath
One of the greatest challenges facing current space weather monitoring operations is forecasting the arrival of coronal mass ejections (CMEs) and solar energetic particles (SEPs). This paper presents a mission concept for operational detection and monitoring of solar weather events as a means of forecasting the arrival of potentially hazardous CMEs and SEPs at Earth-like distances. Foregrounding the operational (rather than scientific) requirements of the system, this work proposes a high-level mission design that could provide detection of solar weather events by tracking associated solar radio bursts, enabling advanced warning of their arrival at Earth. This work concludes that 3–5 small spacecraft equipped with radio spectrometers positioned at the Sun–Earth Lagrange points and in Earth-leading/-trailing orbits could be used to provide this capability, with the and Lagrange points most advantageous for mission performance. While technical developments in CubeSat survivability would be required to enable the SURROUND mission, suitable launch, injection and communication options are identified, indicating its potential feasibility in the near future.
{"title":"Mission concept for SURROUND: Operational space weather detection and tracking using small spacecraft","authors":"Alejandro Macario-Rojas , Dale M. Weigt , L. Alberto Cañizares , Shane A. Maloney , Sophie A. Murray , Peter T. Gallagher , Nicholas H. Crisp , Ciara N. McGrath","doi":"10.1016/j.actaastro.2025.12.055","DOIUrl":"10.1016/j.actaastro.2025.12.055","url":null,"abstract":"<div><div>One of the greatest challenges facing current space weather monitoring operations is forecasting the arrival of coronal mass ejections (CMEs) and solar energetic particles (SEPs). This paper presents a mission concept for operational detection and monitoring of solar weather events as a means of forecasting the arrival of potentially hazardous CMEs and SEPs at Earth-like distances. Foregrounding the operational (rather than scientific) requirements of the system, this work proposes a high-level mission design that could provide detection of solar weather events by tracking associated solar radio bursts, enabling advanced warning of their arrival at Earth. This work concludes that 3–5 small spacecraft equipped with radio spectrometers positioned at the Sun–Earth Lagrange points and in Earth-leading/-trailing orbits could be used to provide this capability, with the <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>5</mn></mrow></msub></math></span> Lagrange points most advantageous for mission performance. While technical developments in CubeSat survivability would be required to enable the SURROUND mission, suitable launch, injection and communication options are identified, indicating its potential feasibility in the near future.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 245-259"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895516","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}
This study presents a novel two-stage optimization framework for enhancing the mobility performance of crewed lunar rovers (CLR) in low-gravity environments, with emphasis on safety and efficiency. In the first stage, a dimensional analysis-based parameter design approach is established, utilizing similarity principles to derive Earth–Moon scaling laws and preliminary suspension parameters through vibration transfer analysis. The second stage involves the construction of an efficient Deep Neural Network (DNN) surrogate model within a dynamics simulation framework that incorporates mechanical modeling of elastic wheel-terrain interaction. The surrogate model is integrated with the SPEA-II multi-objective evolutionary algorithm and TOPSIS decision-making method to achieve global optimization of suspension parameters. To further validate the optimization results, a physics-based virtual prototype of the CLR was developed using an open-source multi-physics simulation platform. Comprehensive evaluation demonstrates that the optimized design exhibit's robust reliability across a wide range of operational scenarios, including variations in travel velocity, payload mass, and terrain roughness.
{"title":"A bi-stage optimization framework for crewed lunar rover","authors":"Kaidi Zhang , Junwei Shi , Jinglai Wu , Chongfeng Zhang , Yunqing Zhang","doi":"10.1016/j.actaastro.2026.01.001","DOIUrl":"10.1016/j.actaastro.2026.01.001","url":null,"abstract":"<div><div>This study presents a novel two-stage optimization framework for enhancing the mobility performance of crewed lunar rovers (CLR) in low-gravity environments, with emphasis on safety and efficiency. In the first stage, a dimensional analysis-based parameter design approach is established, utilizing similarity principles to derive Earth–Moon scaling laws and preliminary suspension parameters through vibration transfer analysis. The second stage involves the construction of an efficient Deep Neural Network (DNN) surrogate model within a dynamics simulation framework that incorporates mechanical modeling of elastic wheel-terrain interaction. The surrogate model is integrated with the SPEA-II multi-objective evolutionary algorithm and TOPSIS decision-making method to achieve global optimization of suspension parameters. To further validate the optimization results, a physics-based virtual prototype of the CLR was developed using an open-source multi-physics simulation platform. Comprehensive evaluation demonstrates that the optimized design exhibit's robust reliability across a wide range of operational scenarios, including variations in travel velocity, payload mass, and terrain roughness.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 438-454"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145893836","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}
Pub Date : 2026-04-01Epub Date: 2025-12-15DOI: 10.1016/j.actaastro.2025.11.006
Scott Dorrington, John Olsen
This paper details the formulation of a parametric economic model that expresses the costs, revenues, and return masses of asteroid mining missions as functions of critical systems, mission, and specific cost parameters. These are used to produce mathematical formulations for key economic figures of merit commonly used in asteroid mining feasibility studies, such as profit, net present value, and mass payback ratio. Several alternative versions of these expressions are formulated for different logistical approaches to asteroid mining missions, with alternatives for mining/extraction method (whole asteroid return or in situ processing), trajectory design (single trip or multiple return trips), and propellant supply strategy (supplied from Earth, refuelling in orbit, or processed in situ from asteroid resources). We further develop a new figure of merit – the break-even mass ratio BEMR – describing the mass of asteroid material required to be returned to produce zero profit or net present value, expressed as a ratio of the spacecraft dry mass. We demonstrate that this break-even mass ratio provides benefits over existing figures of merit in revealing critical delta-V limits above which missions cannot produce positive economic returns, regardless of the return mass. Furthermore, this new metric is invariant to the spacecraft dry mass, allowing it to be applied to a range of spacecraft mass classes. We present a numerical study in which we use this new figure of merit to perform a break-even analysis, assessing the feasibility of the mission alternatives for both single-trip and multi-trip mining missions, over a range of specific impulses from 450 to 3000 s, and target asteroid delta-Vs up to 10 km/s. The results indicate that the typical asteroid mining scenario of a single-trip mission with propellant supplied entirely from Earth is only feasibly for delta-Vs less than 1.8 km/s for chemical propulsion, or 4.5 km/s for electric propulsion cases. We find that multi-trip missions that retrieve small shipments in each trip can be more profitable than a single-trip mission retrieving a large shipment over a long duration. The results also indicate other strategies that may be beneficial in increasing the viability of asteroid mining missions, such as processing return-trip propellant from asteroid resources, maximizing the amount of material retrieved in each return trip, and carrying reserve propellant on the initial trip to mitigate the risks of not finding the desired resources at the target asteroid. These findings may help inform the design of future asteroid mining missions.
{"title":"Parametric economic modelling of asteroid mining architectures","authors":"Scott Dorrington, John Olsen","doi":"10.1016/j.actaastro.2025.11.006","DOIUrl":"10.1016/j.actaastro.2025.11.006","url":null,"abstract":"<div><div>This paper details the formulation of a parametric economic model that expresses the costs, revenues, and return masses of asteroid mining missions as functions of critical systems, mission, and specific cost parameters. These are used to produce mathematical formulations for key economic figures of merit commonly used in asteroid mining feasibility studies, such as profit, net present value, and mass payback ratio. Several alternative versions of these expressions are formulated for different logistical approaches to asteroid mining missions, with alternatives for mining/extraction method (whole asteroid return or in situ processing), trajectory design (single trip or multiple return trips), and propellant supply strategy (supplied from Earth, refuelling in orbit, or processed in situ from asteroid resources). We further develop a new figure of merit – the break-even mass ratio BEMR – describing the mass of asteroid material required to be returned to produce zero profit or net present value, expressed as a ratio of the spacecraft dry mass. We demonstrate that this break-even mass ratio provides benefits over existing figures of merit in revealing critical delta-V limits above which missions cannot produce positive economic returns, regardless of the return mass. Furthermore, this new metric is invariant to the spacecraft dry mass, allowing it to be applied to a range of spacecraft mass classes. We present a numerical study in which we use this new figure of merit to perform a break-even analysis, assessing the feasibility of the mission alternatives for both single-trip and multi-trip mining missions, over a range of specific impulses from 450 to 3000 s, and target asteroid delta-Vs up to 10 km/s. The results indicate that the typical asteroid mining scenario of a single-trip mission with propellant supplied entirely from Earth is only feasibly for delta-Vs less than 1.8 km/s for chemical propulsion, or 4.5 km/s for electric propulsion cases. We find that multi-trip missions that retrieve small shipments in each trip can be more profitable than a single-trip mission retrieving a large shipment over a long duration. The results also indicate other strategies that may be beneficial in increasing the viability of asteroid mining missions, such as processing return-trip propellant from asteroid resources, maximizing the amount of material retrieved in each return trip, and carrying reserve propellant on the initial trip to mitigate the risks of not finding the desired resources at the target asteroid. These findings may help inform the design of future asteroid mining missions.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 19-47"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753473","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}
Pub Date : 2026-04-01Epub Date: 2025-12-30DOI: 10.1016/j.actaastro.2025.12.057
Marco Griffa , Adriano Di Giovanni , Gaspare Santaera , Cesare Stefanini , Donato Romano
Bioregenerative Life Support Systems (BLSS) are a key emerging technology to enable long term space exploration. However, small-scale implementations are difficult to realize and their behavior under space conditions remains scarcely investigated. This study aims at developing and evaluating the smallest self-sustaining, controlled microecosystem suitable for deployment as a CubeSat payload. The system integrates a closed habitat hosting autotrophic (mosses) and heterotrophic (soil micro-arthropods) organisms, along with electronics for environmental monitoring and control. The microecosystem was tested over a 120-day isolation period under laboratory conditions. Tests and simulations of space conditions were also performed. Experimental results demonstrate survival and stability of the biological components during the four-month period, along with successful activation and maintenance of cycling via artificial stimuli. levels decreased from 20000 ppm to 5000 ppm through fixation in plant tissue. Oscillations of 500 ppm were observed with periods of 20, 9, 7 and 1 days. Simulated responses to satellite launch indicated no structural failure, with the maximum stress not exceeding the ultimate strength. Results suggest that small-scale biological modules are optimal candidates for experiments aboard CubeSat-class satellites. Insights from this study may support the development of space BLSSs and inform ecological responses to environmental stressors.
{"title":"Design and evaluation of a miniaturized bioregenerative microecosystem for CubeSat missions","authors":"Marco Griffa , Adriano Di Giovanni , Gaspare Santaera , Cesare Stefanini , Donato Romano","doi":"10.1016/j.actaastro.2025.12.057","DOIUrl":"10.1016/j.actaastro.2025.12.057","url":null,"abstract":"<div><div>Bioregenerative Life Support Systems (BLSS) are a key emerging technology to enable long term space exploration. However, small-scale implementations are difficult to realize and their behavior under space conditions remains scarcely investigated. This study aims at developing and evaluating the smallest self-sustaining, controlled microecosystem suitable for deployment as a CubeSat payload. The system integrates a closed habitat hosting autotrophic (mosses) and heterotrophic (soil micro-arthropods) organisms, along with electronics for environmental monitoring and control. The microecosystem was tested over a 120-day isolation period under laboratory conditions. Tests and simulations of space conditions were also performed. Experimental results demonstrate survival and stability of the biological components during the four-month period, along with successful activation and maintenance of <span><math><msub><mrow><mi>CO</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> cycling via artificial stimuli. <span><math><msub><mrow><mi>CO</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> levels decreased from 20000 ppm to 5000 ppm through fixation in plant tissue. Oscillations of 500 ppm were observed with periods of 20, 9, 7 and 1 days. Simulated responses to satellite launch indicated no structural failure, with the maximum stress not exceeding the ultimate strength. Results suggest that small-scale biological modules are optimal candidates for experiments aboard CubeSat-class satellites. Insights from this study may support the development of space BLSSs and inform ecological responses to environmental stressors.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 278-292"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940440","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}
Pub Date : 2026-04-01Epub Date: 2025-11-23DOI: 10.1016/j.actaastro.2025.11.061
Young-Joo Song , SeungBum Hong , Jun Bang , Jonghee Bae , Moon-Jin Jeon , Soyoung Chung , Shane Fuller , Timothy Stuit
The Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, has been successfully operating in lunar orbit for over two years. During this period, KPLO itself executed four Collision Avoidance Maneuvers (CAMs) to mitigate conjunction risks with other spacecraft in lunar orbit. This paper presents an in-depth analysis of KPLO's CAM operations, from risk assessment to execution, emphasizing the critical role of international collaboration in ensuring lunar orbital safety. The conjunction risk analysis leveraged state-of-the-art tools, including the National Aeronautics and Space Administration's (NASA) Multi-Mission Automated Deep-space Conjunction Assessment Process (MADCAP) and Conjunction Assessment of Risk in Deep Space (CARDS), to identify potential collision threats. Decision-making processes were conducted in coordination with international stakeholders, ensuring timely and effective CAM execution. The operational results of the four CAMs done by KPLO are thoroughly discussed, highlighting the detailed timeline of work process, challenges faced, and efforts made during each event. Furthermore, this study outlines key lessons learned from KPLO's CAM experience, offering practical recommendations to address the growing risks of orbital collisions in the increasingly crowded lunar environment. The findings emphasize the necessity of international collaboration and standardized protocols for sustainable future missions to or at the Moon.
{"title":"KPLO's conjunction mitigation in lunar orbit: Operational results and strategic insights from international collaboration","authors":"Young-Joo Song , SeungBum Hong , Jun Bang , Jonghee Bae , Moon-Jin Jeon , Soyoung Chung , Shane Fuller , Timothy Stuit","doi":"10.1016/j.actaastro.2025.11.061","DOIUrl":"10.1016/j.actaastro.2025.11.061","url":null,"abstract":"<div><div>The Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, has been successfully operating in lunar orbit for over two years. During this period, KPLO itself executed four Collision Avoidance Maneuvers (CAMs) to mitigate conjunction risks with other spacecraft in lunar orbit. This paper presents an in-depth analysis of KPLO's CAM operations, from risk assessment to execution, emphasizing the critical role of international collaboration in ensuring lunar orbital safety. The conjunction risk analysis leveraged state-of-the-art tools, including the National Aeronautics and Space Administration's (NASA) Multi-Mission Automated Deep-space Conjunction Assessment Process (MADCAP) and Conjunction Assessment of Risk in Deep Space (CARDS), to identify potential collision threats. Decision-making processes were conducted in coordination with international stakeholders, ensuring timely and effective CAM execution. The operational results of the four CAMs done by KPLO are thoroughly discussed, highlighting the detailed timeline of work process, challenges faced, and efforts made during each event. Furthermore, this study outlines key lessons learned from KPLO's CAM experience, offering practical recommendations to address the growing risks of orbital collisions in the increasingly crowded lunar environment. The findings emphasize the necessity of international collaboration and standardized protocols for sustainable future missions to or at the Moon.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 637-653"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575255","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}
Pub Date : 2026-04-01Epub Date: 2025-12-26DOI: 10.1016/j.actaastro.2025.12.043
Ruiyao Tao , Yaobao Yin , Li Hu , Naiping Gao , Pengfei He
Interstage separation of launch vehicles is critical for successfully delivering payloads into orbit. To achieve millisecond-level reliable separation for reusable launch vehicles operating under extreme conditions characterized by a supply pressure of 25 MPa and large inertial loads such as 25 t or 55 t, the dynamic response of the high-pressure pneumatic pilot-operated solenoid valve (HPPV) plays a decisive role. Conventional ideal-gas models exhibit insufficient predictive accuracy under high-pressure conditions. To address this limitation, a high-fidelity prediction model for the dynamic opening and closing response of the HPPV is developed. The model incorporates a real-gas equation of state and the multiphysics energy-conversion mechanisms within the valve, and it reveals the mapping relationship between valve response behavior and the overall performance of the separation system. The results show that at a supply pressure of 25 MPa, the opening and closing response times for the full stroke are 101.61 ms and 92.62 ms respectively. Increasing the initial supply pressure enhances the driving capability of the separation process, elevating the excitation voltage reduces the separation delay, and accelerating the main valve motion further expedites the dynamic response of the separation system. Experimental validation demonstrates that the prediction error is less than 4.5%. Parameter optimization enables a reduction of approximately 12% in the total response time. A theoretical basis and essential technical support for the development of highly reliable pneumatic separation systems are provided for reusable launch vehicles.
{"title":"Analysis of a high-pressure pneumatic pilot-operated solenoid valve for interstage separation systems in reusable launch vehicles","authors":"Ruiyao Tao , Yaobao Yin , Li Hu , Naiping Gao , Pengfei He","doi":"10.1016/j.actaastro.2025.12.043","DOIUrl":"10.1016/j.actaastro.2025.12.043","url":null,"abstract":"<div><div>Interstage separation of launch vehicles is critical for successfully delivering payloads into orbit. To achieve millisecond-level reliable separation for reusable launch vehicles operating under extreme conditions characterized by a supply pressure of 25 MPa and large inertial loads such as 25 t or 55 t, the dynamic response of the high-pressure pneumatic pilot-operated solenoid valve (HPPV) plays a decisive role. Conventional ideal-gas models exhibit insufficient predictive accuracy under high-pressure conditions. To address this limitation, a high-fidelity prediction model for the dynamic opening and closing response of the HPPV is developed. The model incorporates a real-gas equation of state and the multiphysics energy-conversion mechanisms within the valve, and it reveals the mapping relationship between valve response behavior and the overall performance of the separation system. The results show that at a supply pressure of 25 MPa, the opening and closing response times for the full stroke are 101.61 ms and 92.62 ms respectively. Increasing the initial supply pressure enhances the driving capability of the separation process, elevating the excitation voltage reduces the separation delay, and accelerating the main valve motion further expedites the dynamic response of the separation system. Experimental validation demonstrates that the prediction error is less than 4.5%. Parameter optimization enables a reduction of approximately 12% in the total response time. A theoretical basis and essential technical support for the development of highly reliable pneumatic separation systems are provided for reusable launch vehicles.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 48-60"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145845198","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}
FACTORS is an M-class mission proposal led by JAXA/ISAS. It aims to elucidate energy coupling mechanisms and mass transport between Earth and space, at around 350–3500 km altitude in high latitude regions. Measurements of the electromagnetic field, particle sampling, and auroral imaging are planned. Simultaneous data at several kilometres to tens of kilometres apart will be obtained, using two satellites in formation flight in an eccentric polar orbit. Differential aerodynamic drag offers a promising resource for propellant-free formation control, since the perigee is located in the atmosphere. A control method for an in-track linear formation is developed and tested using a high-fidelity numerical orbit simulator. Disturbances are added to represent attitude control error, aerodynamic lift, and open-loop command uplink with space weather prediction error. Good performance is obtained even for close-proximity operations with km-scale separation. Based on the results, fully aerodynamic control is possible, though a thruster is desirable for perigee altitude adjustment and out-of-plane manoeuvring. To the authors’ knowledge, this is the first detailed study on formation flight control via differential drag in an eccentric orbit.
{"title":"Feasibility assessment of formation flight control by differential drag in eccentric orbit for the FACTORS mission","authors":"Maximilien Berthet , Yusuke Maru , Yoshifumi Saito , Takefumi Mitani , Iku Shinohara , Kazushi Asamura","doi":"10.1016/j.actaastro.2026.01.017","DOIUrl":"10.1016/j.actaastro.2026.01.017","url":null,"abstract":"<div><div>FACTORS is an M-class mission proposal led by JAXA/ISAS. It aims to elucidate energy coupling mechanisms and mass transport between Earth and space, at around 350–3500 km altitude in high latitude regions. Measurements of the electromagnetic field, particle sampling, and auroral imaging are planned. Simultaneous data at several kilometres to tens of kilometres apart will be obtained, using two satellites in formation flight in an eccentric polar orbit. Differential aerodynamic drag offers a promising resource for propellant-free formation control, since the perigee is located in the atmosphere. A control method for an in-track linear formation is developed and tested using a high-fidelity numerical orbit simulator. Disturbances are added to represent attitude control error, aerodynamic lift, and open-loop command uplink with space weather prediction error. Good performance is obtained even for close-proximity operations with km-scale separation. Based on the results, fully aerodynamic control is possible, though a thruster is desirable for perigee altitude adjustment and out-of-plane manoeuvring. To the authors’ knowledge, this is the first detailed study on formation flight control via differential drag in an eccentric orbit.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 556-574"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978438","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}
Pub Date : 2026-04-01Epub Date: 2026-01-12DOI: 10.1016/j.actaastro.2026.01.019
Szabolcs Velkei , László L. Kiss , Károly Vass , Norton O. Szabó , Krisztián Sárneczky
Konkoly Observatory is conducting the most successful NEO survey project in Europe with a total number of NEOs found in the past four years in excess of 250, with three imminent impactors discovered between 2022 and 2024. Recently, supported by the European Space Agency, we started the implementation of a new search technique that is using machine learning algorithms to accelerate real-time image analysis with the scope of finding extreme trailed images of the smallest and nearest NEOs passing by. We have created a custom deep-learning model that was trained on a large dataset of astronomical images and their associated annotations. In addition to the real observations from the Piszkéstető Mountain Station of the Konkoly Observatory, we have also created a huge synthetic photorealistic training dataset to improve the precision and accuracy of the neural network. As a result, the model successfully learnt to recognize patterns and features in the images that are indicative of NEOs and space debris. The main goal was to have an optimized deep learning model to perform this analysis in real-time, providing quick and reliable detection that is made possible by the AI-based robust image-artifact decomposition for false positive suppression. The outcome of this project is a service that can quickly and accurately detect NEOs and space debris on astronomical images, potentially increasing the number of discoveries and improving the speed and reliability of the discovery process. The system has been evaluated using a set of rigorous tests and is benchmarked against existing methods. We provide valuable insights into the feasibility of using deep learning techniques for this type of image analysis problem and will lay the groundwork for future work in this field.
{"title":"Real-time discovery of near-earth objects via accelerated image analysis with AI methods","authors":"Szabolcs Velkei , László L. Kiss , Károly Vass , Norton O. Szabó , Krisztián Sárneczky","doi":"10.1016/j.actaastro.2026.01.019","DOIUrl":"10.1016/j.actaastro.2026.01.019","url":null,"abstract":"<div><div>Konkoly Observatory is conducting the most successful NEO survey project in Europe with a total number of NEOs found in the past four years in excess of 250, with three imminent impactors discovered between 2022 and 2024. Recently, supported by the European Space Agency, we started the implementation of a new search technique that is using machine learning algorithms to accelerate real-time image analysis with the scope of finding extreme trailed images of the smallest and nearest NEOs passing by. We have created a custom deep-learning model that was trained on a large dataset of astronomical images and their associated annotations. In addition to the real observations from the Piszkéstető Mountain Station of the Konkoly Observatory, we have also created a huge synthetic photorealistic training dataset to improve the precision and accuracy of the neural network. As a result, the model successfully learnt to recognize patterns and features in the images that are indicative of NEOs and space debris. The main goal was to have an optimized deep learning model to perform this analysis in real-time, providing quick and reliable detection that is made possible by the AI-based robust image-artifact decomposition for false positive suppression. The outcome of this project is a service that can quickly and accurately detect NEOs and space debris on astronomical images, potentially increasing the number of discoveries and improving the speed and reliability of the discovery process. The system has been evaluated using a set of rigorous tests and is benchmarked against existing methods. We provide valuable insights into the feasibility of using deep learning techniques for this type of image analysis problem and will lay the groundwork for future work in this field.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 547-555"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978437","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}
Pub Date : 2026-04-01Epub Date: 2026-01-02DOI: 10.1016/j.actaastro.2025.12.052
Paweł Urbanski, Piotr Szyszka
Compact, low-power X-ray sources are critical for enabling XRF capabilities within the strict mass, volume and power budgets of small planetary landers and rovers. This work evaluates the performance of a MEMS-based X-ray source that integrates a field emission electron emitter, a transmission target, and an on-chip vacuum micro-pump, providing intense soft X-ray radiation suitable for the excitation of low-Z elements. The source was tested in laboratory conditions through the XRF analysis of four lunar regolith simulants (LHS-1D, LHS-1, LMS-1D and LSP-2). The elemental compositions retrieved from the spectra closely match the reference values supplied by the manufacturer, confirming the suitability of the MEMS device for the characterization of lunar surface materials. Owing to its reduced mass, volume and power consumption, the MEMS source offers substantial advantages over conventional X-ray tubes, particularly for resource-limited missions and applications related to in-situ resource utilization (ISRU). The increased efficiency in exciting low-energy fluorescence lines further enhances its applicability to regolith studies. The results demonstrate that MEMS X-ray sources constitute a promising technological alternative for future planetary science missions, supporting both scientific investigations and on-site resource monitoring.
{"title":"MEMS X-ray source enables ultra-compact XRF spectrometry for in situ extraterrestrial surface analysis","authors":"Paweł Urbanski, Piotr Szyszka","doi":"10.1016/j.actaastro.2025.12.052","DOIUrl":"10.1016/j.actaastro.2025.12.052","url":null,"abstract":"<div><div>Compact, low-power X-ray sources are critical for enabling XRF capabilities within the strict mass, volume and power budgets of small planetary landers and rovers. This work evaluates the performance of a MEMS-based X-ray source that integrates a field emission electron emitter, a transmission target, and an on-chip vacuum micro-pump, providing intense soft X-ray radiation suitable for the excitation of low-Z elements. The source was tested in laboratory conditions through the XRF analysis of four lunar regolith simulants (LHS-1D, LHS-1, LMS-1D and LSP-2). The elemental compositions retrieved from the spectra closely match the reference values supplied by the manufacturer, confirming the suitability of the MEMS device for the characterization of lunar surface materials. Owing to its reduced mass, volume and power consumption, the MEMS source offers substantial advantages over conventional X-ray tubes, particularly for resource-limited missions and applications related to in-situ resource utilization (ISRU). The increased efficiency in exciting low-energy fluorescence lines further enhances its applicability to regolith studies. The results demonstrate that MEMS X-ray sources constitute a promising technological alternative for future planetary science missions, supporting both scientific investigations and on-site resource monitoring.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 192-198"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145893837","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}
Polymers are widely used in space as thermally controlled materials. Among them, polyetherimide (PEI) stands out and is a promising candidate as a thermally controllable material because of its high durability and transparency. However, the degradation mechanism under ultraviolet (UV) light in the space environment is not completely known. In this study, we monitored the degradation of PEI under UV light irradiation in a vacuum atmosphere to simulate the space environment. Chemical analyses were performed using X-ray photoelectron spectroscopy (XPS), surface attenuated total reflectance infrared (ATR-IR) measurement, and cross-sectional ATR-IR measurement. The relationship between the solar absorptance with increasing irradiation dose and chemical degradation was also a subject of study. XPS measurements revealed that structural changes occurred within a few nanometers of the surface in a relatively short time after irradiation. Additionally, there was nearly no change even when the irradiation dose was increased thereafter. Surface ATR-IR measurements demonstrated that a region of several micrometers on the surface gradually underwent structural changes owing to the formation of a crosslinked structure upon UV irradiation, and cross-sectional ATR-IR measurements indicated that were more closely correlated with the value of solar absorptance.
{"title":"UV degradation of poly(ether imide) film under vacuum condition and its examination by chemical analyses","authors":"Shogo Yamane , Kazuki Yukumatsu , Yuki Horiuchi , Hideaki Hagihara , Yugo Kimoto , Junji Mizukado","doi":"10.1016/j.actaastro.2026.01.012","DOIUrl":"10.1016/j.actaastro.2026.01.012","url":null,"abstract":"<div><div>Polymers are widely used in space as thermally controlled materials. Among them, polyetherimide (PEI) stands out and is a promising candidate as a thermally controllable material because of its high durability and transparency. However, the degradation mechanism under ultraviolet (UV) light in the space environment is not completely known. In this study, we monitored the degradation of PEI under UV light irradiation in a vacuum atmosphere to simulate the space environment. Chemical analyses were performed using X-ray photoelectron spectroscopy (XPS), surface attenuated total reflectance infrared (ATR-IR) measurement, and cross-sectional ATR-IR measurement. The relationship between the solar absorptance with increasing irradiation dose and chemical degradation was also a subject of study. XPS measurements revealed that structural changes occurred within a few nanometers of the surface in a relatively short time after irradiation. Additionally, there was nearly no change even when the irradiation dose was increased thereafter. Surface ATR-IR measurements demonstrated that a region of several micrometers on the surface gradually underwent structural changes owing to the formation of a crosslinked structure upon UV irradiation, and cross-sectional ATR-IR measurements indicated that were more closely correlated with the value of solar absorptance.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 484-490"},"PeriodicalIF":3.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902735","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号