Pub Date : 2026-01-05DOI: 10.1016/j.actaastro.2026.01.014
Manuel Calvo , Antonio Elipe, Luis Rández
Accurate and efficient solution of the Elliptic Kepler Equation (EKE) is fundamental in orbital mechanics and spacecraft trajectory analysis. In this work, we present a family of piecewise rational approximations for solving the EKE, based on Padé and Hermite-type formulations. The proposed approaches replaces the transcendental term with Hermite and Piecewise Padé-Type (PPT) approximants, the later originally introduced by Brezinski, providing higher accuracy than the traditional Piecewise Padé (PP) method of Wu et al. without increasing computational cost. With these approximants, the resulting rational form reduces the EKE to a cubic equation that can be solved analytically, making it suitable for onboard implementations or large-scale orbit propagation tasks. Numerical experiments demonstrate that the PPT-based solution significantly improves accuracy for moderate and high eccentricities, including near-parabolic cases. Additionally, optimized parameter selection in general [3/2] rational representations yields further accuracy gains. These results show that the proposed piecewise rational method offers a reliable and computationally efficient alternative for precise orbital position determination across a wide range of eccentricities.
精确、高效地求解椭圆开普勒方程是轨道力学和航天器轨道分析的基础。在这项工作中,我们提出了一组分段有理近似来求解EKE, F(E; E)≡E−esinE=M,基于pad和hermite型公式。本文提出的方法用Hermite和Piecewise pad - type (PPT)近似代替了超越项sin,后者最初是由Brezinski引入的,在不增加计算成本的情况下,提供了比Wu等人的传统Piecewise pad - type (PP)方法更高的精度。通过这些近似,得到的有理形式将EKE简化为可以解析求解的三次方程,使其适合于机载实现或大规模轨道传播任务。数值实验表明,基于ppt的解决方案显著提高了中、高偏心率的精度,包括近抛物线情况。此外,在一般[3/2]理性表示中优化的参数选择可以进一步提高精度。这些结果表明,所提出的分段合理方法提供了一种可靠且计算效率高的替代方法,可以在大范围的偏心距范围内精确确定轨道位置。
{"title":"Piecewise rational Padé and Hermite approximations for the elliptic Kepler equation","authors":"Manuel Calvo , Antonio Elipe, Luis Rández","doi":"10.1016/j.actaastro.2026.01.014","DOIUrl":"10.1016/j.actaastro.2026.01.014","url":null,"abstract":"<div><div>Accurate and efficient solution of the Elliptic Kepler Equation (EKE) is fundamental in orbital mechanics and spacecraft trajectory analysis. In this work, we present a family of piecewise rational approximations for solving the EKE, <span><span><span><math><mrow><mi>F</mi><mrow><mo>(</mo><mi>E</mi><mo>;</mo><mi>e</mi><mo>)</mo></mrow><mo>≡</mo><mi>E</mi><mo>−</mo><mi>e</mi><mo>sin</mo><mi>E</mi><mo>=</mo><mi>M</mi><mo>,</mo></mrow></math></span></span></span>based on Padé and Hermite-type formulations. The proposed approaches replaces the transcendental term <span><math><mrow><mo>sin</mo><mi>E</mi></mrow></math></span> with Hermite and Piecewise Padé-Type (PPT) approximants, the later originally introduced by Brezinski, providing higher accuracy than the traditional Piecewise Padé (PP) method of Wu et al. without increasing computational cost. With these approximants, the resulting rational form reduces the EKE to a cubic equation that can be solved analytically, making it suitable for onboard implementations or large-scale orbit propagation tasks. Numerical experiments demonstrate that the PPT-based solution significantly improves accuracy for moderate and high eccentricities, including near-parabolic cases. Additionally, optimized parameter selection in general [3/2] rational representations yields further accuracy gains. These results show that the proposed piecewise rational method offers a reliable and computationally efficient alternative for precise orbital position determination across a wide range of eccentricities.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 199-206"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902758","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 : 2026-01-05DOI: 10.1016/j.actaastro.2026.01.003
Jieguang Huang , Xiaonan Cheng , Linhai Hao , Qian Wang , Jun Luo , Lehua Qi
Metal additive manufacturing (MAM) offers transformative potential for producing complex, high-performance components directly in space. However, a systematic understanding of which MAM processes are truly viable for in-space deployment, their current maturity levels, and the critical challenges that constrain further advancement remains limited. This review provides a comprehensive assessment of the adaptability of major MAM technologies, including Direct Energy Deposition (DED), Powder Bed Fusion (PBF), Material Extrusion (MEX), Material Jetting (MJT), and Vat Photopolymerization (VPP), to the unique conditions of microgravity and vacuum. By integrating dispersed findings into a unified framework that links process physics with environmental constraints, we offer a comparative analysis of terrestrial versus in-space operation, emphasizing how microgravity and vacuum reshape system architectures, melt-pool behavior, interlayer bonding, defect formation, and overall process capabilities. Key challenges related to equipment miniaturization and space adaptation, process monitoring and control, melt-solidification dynamics, and post-processing and quality assurance are critically examined, together with their implications for process-structure-property relationships under non-terrestrial conditions. Building on these insights, a technology-readiness roadmap is proposed to highlight priority research directions required to transition from isolated laboratory demonstrations toward robust, flight-ready MAM systems. This work establishes an integrated understanding of the state of the art and outlines future pathways for advancing metallic additive manufacturing in extreme space environments.
{"title":"Progress in metal additive manufacturing for space applications: A comprehensive review","authors":"Jieguang Huang , Xiaonan Cheng , Linhai Hao , Qian Wang , Jun Luo , Lehua Qi","doi":"10.1016/j.actaastro.2026.01.003","DOIUrl":"10.1016/j.actaastro.2026.01.003","url":null,"abstract":"<div><div>Metal additive manufacturing (MAM) offers transformative potential for producing complex, high-performance components directly in space. However, a systematic understanding of which MAM processes are truly viable for in-space deployment, their current maturity levels, and the critical challenges that constrain further advancement remains limited. This review provides a comprehensive assessment of the adaptability of major MAM technologies, including Direct Energy Deposition (DED), Powder Bed Fusion (PBF), Material Extrusion (MEX), Material Jetting (MJT), and Vat Photopolymerization (VPP), to the unique conditions of microgravity and vacuum. By integrating dispersed findings into a unified framework that links process physics with environmental constraints, we offer a comparative analysis of terrestrial versus in-space operation, emphasizing how microgravity and vacuum reshape system architectures, melt-pool behavior, interlayer bonding, defect formation, and overall process capabilities. Key challenges related to equipment miniaturization and space adaptation, process monitoring and control, melt-solidification dynamics, and post-processing and quality assurance are critically examined, together with their implications for process-structure-property relationships under non-terrestrial conditions. Building on these insights, a technology-readiness roadmap is proposed to highlight priority research directions required to transition from isolated laboratory demonstrations toward robust, flight-ready MAM systems. This work establishes an integrated understanding of the state of the art and outlines future pathways for advancing metallic additive manufacturing in extreme space environments.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 346-377"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902759","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 : 2026-01-05DOI: 10.1016/j.actaastro.2025.12.063
Ping-Han Huang , Yueh-Heng Li
This study explores the optimization of vacuum arc thruster (VAT) performance through precise control of an inductive energy storage circuit. Two experimental approaches were investigated: (1) By varying the inductor charging time under single-pulse ignition, this experiment aims to determine the relationship between the circuit components and the performance of the VAT. (2) Implementing a dual-pulse ignition scheme with controlled inter-pulse delays, which aims to determine whether two ignitions interact with each other. In the single-pulse tests, maximum thrust performance occurred when the inductor current reached its peak. Reducing the charging current to approximately 76 % of this peak resulted in decreases of 28 %, 38 %, and 42 % in discharge energy, plasma plume, and mass ablation rate, respectively. These results demonstrate that VAT performance is strongly dependent on the energy stored in the inductor and the magnitude of the induced voltage generated upon IGBT turn-off.
In the dual-pulse tests, triggering two identical inductive circuits with a 3 μs inter-pulse delay significantly enhanced performance. Compared to a 3000 μs delay, this shortest delay resulted in a 68.74 % lower breakdown voltage for the second pulse, a 15.22 % increase in total discharge energy, a 98.7 % extension in discharge duration, and a 356 % increase in the ablation rate.
The highest thrust of 12.07 μN s and thrust-to-power ratio of 29.97 μN s/W were achieved at this shortest delay. These findings highlight that both induced voltage characteristics and short inter-pulse plasma dynamics play critical roles in maximizing VAT performance, offering practical insights for high-efficiency pulsed electric propulsion system design.
{"title":"Optimization of vacuum arc thruster efficiency through inductive energy storage circuit control","authors":"Ping-Han Huang , Yueh-Heng Li","doi":"10.1016/j.actaastro.2025.12.063","DOIUrl":"10.1016/j.actaastro.2025.12.063","url":null,"abstract":"<div><div>This study explores the optimization of vacuum arc thruster (VAT) performance through precise control of an inductive energy storage circuit. Two experimental approaches were investigated: (1) By varying the inductor charging time under single-pulse ignition, this experiment aims to determine the relationship between the circuit components and the performance of the VAT. (2) Implementing a dual-pulse ignition scheme with controlled inter-pulse delays, which aims to determine whether two ignitions interact with each other. In the single-pulse tests, maximum thrust performance occurred when the inductor current reached its peak. Reducing the charging current to approximately 76 % of this peak resulted in decreases of 28 %, 38 %, and 42 % in discharge energy, plasma plume, and mass ablation rate, respectively. These results demonstrate that VAT performance is strongly dependent on the energy stored in the inductor and the magnitude of the induced voltage generated upon IGBT turn-off.</div><div>In the dual-pulse tests, triggering two identical inductive circuits with a <strong>3</strong> μs inter-pulse delay significantly enhanced performance. Compared to a 3000 μs delay, this shortest delay resulted in a 68.74 % lower breakdown voltage for the second pulse, a 15.22 % increase in total discharge energy, a 98.7 % extension in discharge duration, and a 356 % increase in the ablation rate.</div><div>The highest thrust of 12.07 μN s and thrust-to-power ratio of 29.97 μN s/W were achieved at this shortest delay. These findings highlight that both induced voltage characteristics and short inter-pulse plasma dynamics play critical roles in maximizing VAT performance, offering practical insights for high-efficiency pulsed electric propulsion system design.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 32-47"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902739","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":"2026-01-05","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}
Pub Date : 2026-01-05DOI: 10.1016/j.actaastro.2026.01.008
Wang Zhao , Shujun Tan
A dimensionality reduction method addressing the high-dimensional and singular nature of Pogo state-space models is studied, beneficial for advancing active suppression techniques. A comprehensive approach integrating eigenspace transformation with Modal Cost Analysis (MCA) is proposed. Direct modal analysis of the coupled Pogo system yields unreliable modal costs due to distinct propulsion and structural system characteristics. Therefore, the coupling between systems is explicitly considered. Suitable inputs and outputs are designed for each system. Specifically, the Pogo system is first decoupled via eigenspace transformation. MCA is then performed, retaining high-cost modes within the Pogo system to construct the reduced-dimensional model. Validation through frequency domain analysis and time domain simulation demonstrates that the method effectively retains high-cost modes under varying conditions, yielding a more accurate reduced-dimensional model. The framework offers generalized applicability to reusable rocket development.
{"title":"Model reduction of pogo suppression for liquid launch vehicles via decoupled modal cost selection","authors":"Wang Zhao , Shujun Tan","doi":"10.1016/j.actaastro.2026.01.008","DOIUrl":"10.1016/j.actaastro.2026.01.008","url":null,"abstract":"<div><div>A dimensionality reduction method addressing the high-dimensional and singular nature of Pogo state-space models is studied, beneficial for advancing active suppression techniques. A comprehensive approach integrating eigenspace transformation with Modal Cost Analysis (MCA) is proposed. Direct modal analysis of the coupled Pogo system yields unreliable modal costs due to distinct propulsion and structural system characteristics. Therefore, the coupling between systems is explicitly considered. Suitable inputs and outputs are designed for each system. Specifically, the Pogo system is first decoupled via eigenspace transformation. MCA is then performed, retaining high-cost modes within the Pogo system to construct the reduced-dimensional model. Validation through frequency domain analysis and time domain simulation demonstrates that the method effectively retains high-cost modes under varying conditions, yielding a more accurate reduced-dimensional model. The framework offers generalized applicability to reusable rocket development.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 473-483"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903437","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 : 2026-01-05DOI: 10.1016/j.actaastro.2026.01.010
Zhi Yin , Tianxing Chen , Xueqin Chen , Ming Liu , Jian Chen
Size constraints restrict the surface area of solar arrays and thus the generated power for CubeSats. Therefore, the efficiency of the electrical power system (EPS) is the most important feature in the design of CubeSats. To maintain a high efficiency over long-term use of CubeSats, this work describes the implementation of a digital maximum power point tracking (MPPT) technique devised for EPS, which is based on an improved bat algorithm (BA) and runs on the lower computer. To ensure the universality of the designed control method, a typical system of a 6U CubeSat is constructed for subsequent simulations and experiments. The new proposed MPPT method utilizes the predicted degradation and telemetry temperature of solar arrays to change the initial population of BA, and refers to the convergence process of gray wolf optimization (GWO) to optimize tracking speed. Numerical simulation results show that the average efficiency of the new proposed algorithm is 97.29% across all simulations, compared to 94.48% for conventional BA. Meanwhile, the proposed algorithm shows a marked reduction in both standard deviation and coefficient of variation, providing a more stable tracking. Finally, a hardware testing system is established to validate the MPPT method based on the improved BA, and it can approach the maximum power point (MPP) of the simulated solar array within about 30 ms with a 2.5 ms control cycle.
{"title":"Digital maximum power point tracking for electrical power system of CubeSats based on bat algorithm","authors":"Zhi Yin , Tianxing Chen , Xueqin Chen , Ming Liu , Jian Chen","doi":"10.1016/j.actaastro.2026.01.010","DOIUrl":"10.1016/j.actaastro.2026.01.010","url":null,"abstract":"<div><div>Size constraints restrict the surface area of solar arrays and thus the generated power for CubeSats. Therefore, the efficiency of the electrical power system (EPS) is the most important feature in the design of CubeSats. To maintain a high efficiency over long-term use of CubeSats, this work describes the implementation of a digital maximum power point tracking (MPPT) technique devised for EPS, which is based on an improved bat algorithm (BA) and runs on the lower computer. To ensure the universality of the designed control method, a typical system of a 6U CubeSat is constructed for subsequent simulations and experiments. The new proposed MPPT method utilizes the predicted degradation and telemetry temperature of solar arrays to change the initial population of BA, and refers to the convergence process of gray wolf optimization (GWO) to optimize tracking speed. Numerical simulation results show that the average efficiency of the new proposed algorithm is 97.29% across all simulations, compared to 94.48% for conventional BA. Meanwhile, the proposed algorithm shows a marked reduction in both standard deviation and coefficient of variation, providing a more stable tracking. Finally, a hardware testing system is established to validate the MPPT method based on the improved BA, and it can approach the maximum power point (MPP) of the simulated solar array within about 30 ms with a 2.5 ms control cycle.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 170-180"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897508","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 : 2026-01-05DOI: 10.1016/j.actaastro.2026.01.013
Chen Qing, Gang Zhang
This paper studies the multi-interceptor and multi-target impulsive cooperative interception problem based on reachable domain coverage. Two problems are mainly solved including the multi-to-multi target assignment problem and the multi-to-one cooperative interception problem. According to the linearized uncertainty propagation model, the envelopes of fixed-time reachable domains for both the interceptors and the targets are described by ellipsoidal equation. Then, for the one-to-one interception case, an analytical method is proposed to obtain the impulse magnitude for covering the target’s reachable domain with given impulse time. Based on the rapid estimations of fuel consumption for the one-to-one case, the particle swarm optimization technique is employed to resolve the multi-to-multi target assignment problem. In addition, the multi-to-one reachable domain coverage constraint is converted into the inequality constraint, which is easy to judge in the optimization process. Finally, the multi-to-one cooperative interception problem for optimal fuel consumption is optimized through the interior-point algorithm. Numerical results show that the proposed multi-to-multi target assignment method can rapidly obtain the assignment scheme, and the multi-to-one cooperative interception strategy can reduce the fuel consumption when compared with the one-to-one interception.
{"title":"Multi-to-multi spacecraft impulsive cooperative interception based on reachable domain coverage","authors":"Chen Qing, Gang Zhang","doi":"10.1016/j.actaastro.2026.01.013","DOIUrl":"10.1016/j.actaastro.2026.01.013","url":null,"abstract":"<div><div>This paper studies the multi-interceptor and multi-target impulsive cooperative interception problem based on reachable domain coverage. Two problems are mainly solved including the multi-to-multi target assignment problem and the multi-to-one cooperative interception problem. According to the linearized uncertainty propagation model, the envelopes of fixed-time reachable domains for both the interceptors and the targets are described by ellipsoidal equation. Then, for the one-to-one interception case, an analytical method is proposed to obtain the impulse magnitude for covering the target’s reachable domain with given impulse time. Based on the rapid estimations of fuel consumption for the one-to-one case, the particle swarm optimization technique is employed to resolve the multi-to-multi target assignment problem. In addition, the multi-to-one reachable domain coverage constraint is converted into the inequality constraint, which is easy to judge in the optimization process. Finally, the multi-to-one cooperative interception problem for optimal fuel consumption is optimized through the interior-point algorithm. Numerical results show that the proposed multi-to-multi target assignment method can rapidly obtain the assignment scheme, and the multi-to-one cooperative interception strategy can reduce the fuel consumption when compared with the one-to-one interception.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 234-244"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902756","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 : 2026-01-05DOI: 10.1016/j.actaastro.2026.01.007
Yingxin Zhang , Jia Tian , Shufeng Zhang , Xiaoming Tan , Jingzhou Zhang , Fulei Zhu , Zhengwei Fan , Jingyang Li , Wenqian Hao
The extreme thermal loads induced by rotating detonation waves pose critical challenges to the thermal protection of rotating detonation combustors (RDCs). This study investigates the feasibility of gas transpiration cooling for RDC thermal protection, establishing a localized physical model of axial porous media to simulate detonation wave-coolant interactions. By comparing transpiration cooling characteristics under varying coolant mass flow rates and porosities, the study reveals distinct cooling mechanisms between rotating detonation wave and oblique shock wave regions. Numerical results indicate that transpiration cooling forms a 200–720 K porous wall thermal barrier, isolates the 2280–2800 K detonation core, and reduces wall heat flux by 72 % and pressure peaks by 20–83 %. Optimal cooling performance requires partitioned porosity: a sloping shock zone of 0.5 maximizes efficiency, while a detonation zone of 0.4 avoids increased heat flux due to flow instability. A 0.5 % coolant-to-mainstream mass flow ratio provides continuous thermal protection with a cooling efficiency of 0.72, while 1.0 % causes film breakage and temperature fluctuations. The porous medium acts as a chemical regulator to inhibit combustion and increase water vapor concentration through reverse osmosis to achieve inert gas buffering. The pressure dissipates within 12μs, but the thermal decay lags due to solid-phase inertia, which underscores the need for zonal porosity design and precise coolant control to achieve RDC stability.
{"title":"Numerical investigation of gas transpiration cooling for rotating detonation combustor","authors":"Yingxin Zhang , Jia Tian , Shufeng Zhang , Xiaoming Tan , Jingzhou Zhang , Fulei Zhu , Zhengwei Fan , Jingyang Li , Wenqian Hao","doi":"10.1016/j.actaastro.2026.01.007","DOIUrl":"10.1016/j.actaastro.2026.01.007","url":null,"abstract":"<div><div>The extreme thermal loads induced by rotating detonation waves pose critical challenges to the thermal protection of rotating detonation combustors (RDCs). This study investigates the feasibility of gas transpiration cooling for RDC thermal protection, establishing a localized physical model of axial porous media to simulate detonation wave-coolant interactions. By comparing transpiration cooling characteristics under varying coolant mass flow rates and porosities, the study reveals distinct cooling mechanisms between rotating detonation wave and oblique shock wave regions. Numerical results indicate that transpiration cooling forms a 200–720 K porous wall thermal barrier, isolates the 2280–2800 K detonation core, and reduces wall heat flux by 72 % and pressure peaks by 20–83 %. Optimal cooling performance requires partitioned porosity: a sloping shock zone of 0.5 maximizes efficiency, while a detonation zone of 0.4 avoids increased heat flux due to flow instability. A 0.5 % coolant-to-mainstream mass flow ratio provides continuous thermal protection with a cooling efficiency of 0.72, while 1.0 % causes film breakage and temperature fluctuations. The porous medium acts as a chemical regulator to inhibit combustion and increase water vapor concentration through reverse osmosis to achieve inert gas buffering. The pressure dissipates within 12μs, but the thermal decay lags due to solid-phase inertia, which underscores the need for zonal porosity design and precise coolant control to achieve RDC stability.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 293-313"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903432","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 : 2026-01-05DOI: 10.1016/j.actaastro.2025.12.058
Yuqi Sun , Xiande Wu , Hyuk Park , Chao Dong
A method for integrated task allocation and orbital maneuver planning is devised to address scenarios where a satellite swarm responds to unreachable targets. To observe more targets earlier and at a lower maneuver cost, this paper proposes an improved tabu search algorithm for remote sensing satellite swarm task planning. The proposed method improves the tabu search algorithm by incorporating the parallel dynamic dual-search strategy to optimize target allocation in the satellite swarm and observation sequence of swarm members. By dynamically grouping and refactoring the code, the parallel search strategy reduces the search space and enhances computational efficiency. A simulation scenario is provided to verify the efficiency and feasibility of the proposed algorithm in responding to multiple unreachable targets. The results show the fitness trend with 15 satellites and 150–300 targets. Besides its feasibility, the proposed method results in a more than ten-fold improvement in calculation efficiency.
{"title":"Orbit maneuver planning of earth observation satellite swarm for unreachable targets","authors":"Yuqi Sun , Xiande Wu , Hyuk Park , Chao Dong","doi":"10.1016/j.actaastro.2025.12.058","DOIUrl":"10.1016/j.actaastro.2025.12.058","url":null,"abstract":"<div><div>A method for integrated task allocation and orbital maneuver planning is devised to address scenarios where a satellite swarm responds to unreachable targets. To observe more targets earlier and at a lower maneuver cost, this paper proposes an improved tabu search algorithm for remote sensing satellite swarm task planning. The proposed method improves the tabu search algorithm by incorporating the parallel dynamic dual-search strategy to optimize target allocation in the satellite swarm and observation sequence of swarm members. By dynamically grouping and refactoring the code, the parallel search strategy reduces the search space and enhances computational efficiency. A simulation scenario is provided to verify the efficiency and feasibility of the proposed algorithm in responding to multiple unreachable targets. The results show the fitness trend with 15 satellites and 150–300 targets. Besides its feasibility, the proposed method results in a more than ten-fold improvement in calculation efficiency.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 620-636"},"PeriodicalIF":3.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902757","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 : 2026-01-03DOI: 10.1016/j.actaastro.2025.12.064
Xiaosi Li , Junlong Zhang , Guowei Luan , Youyin Wang , Hongchao Qiu , Wen Bao
The injection scheme has a significant effect on the mixing and combustion of the fuel, as well as the spatial distribution of the main combustion zone, which is crucial for the performance of the scramjet. In this study, the zonal combustion under several typical asymmetric strut/wall combined fuel injection schemes was numerically investigated. The flow field characteristics, mixing and combustion performance, the combustor parameters distributions, as well as the impact of zonal combustion on the aerodynamic performance of the nozzle were analyzed. The results indicate that zonal combustion can be established in a supersonic combustor through zonal fuel injection, wherein combustion zones and non-reacting zones coexist in the circumferential direction of the combustor while exhibiting distinct flow and combustion characteristics. Besides, at an identical equivalence ratio, zonal fuel injection schemes not only yield lower mixing and combustion efficiencies compared to a uniform injection scheme, but also alters both the wall pressure distribution along the combustor and the gas parameter distribution at combustor outlet. Ultimately, zonal combustion affects the aerodynamic performance of scramjet nozzles, such as lift and lateral force. The analysis results of zonal combustion in this paper were beneficial to the optimization of asymmetric injection scheme in supersonic combustor for future investigations and offer a novel perspective for flight control in hypersonic vehicles.
{"title":"Numerical study on zonal combustion characteristics in supersonic combustor under asymmetric injection scheme","authors":"Xiaosi Li , Junlong Zhang , Guowei Luan , Youyin Wang , Hongchao Qiu , Wen Bao","doi":"10.1016/j.actaastro.2025.12.064","DOIUrl":"10.1016/j.actaastro.2025.12.064","url":null,"abstract":"<div><div>The injection scheme has a significant effect on the mixing and combustion of the fuel, as well as the spatial distribution of the main combustion zone, which is crucial for the performance of the scramjet. In this study, the zonal combustion under several typical asymmetric strut/wall combined fuel injection schemes was numerically investigated. The flow field characteristics, mixing and combustion performance, the combustor parameters distributions, as well as the impact of zonal combustion on the aerodynamic performance of the nozzle were analyzed. The results indicate that zonal combustion can be established in a supersonic combustor through zonal fuel injection, wherein combustion zones and non-reacting zones coexist in the circumferential direction of the combustor while exhibiting distinct flow and combustion characteristics. Besides, at an identical equivalence ratio, zonal fuel injection schemes not only yield lower mixing and combustion efficiencies compared to a uniform injection scheme, but also alters both the wall pressure distribution along the combustor and the gas parameter distribution at combustor outlet. Ultimately, zonal combustion affects the aerodynamic performance of scramjet nozzles, such as lift and lateral force. The analysis results of zonal combustion in this paper were beneficial to the optimization of asymmetric injection scheme in supersonic combustor for future investigations and offer a novel perspective for flight control in hypersonic vehicles.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"241 ","pages":"Pages 260-277"},"PeriodicalIF":3.4,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145893822","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}