Acta Astronautica最新文献

{"title":"Efficiency Metrics and Numerical Simulation Procedure for Atmosphere-Breathing Electric Propulsion (ABEP) Intake Designs","authors":"M.B. Agir ,&nbsp;N.H. Crisp ,&nbsp;K.L. Smith ,&nbsp;P.C.E. Roberts ,&nbsp;Z. Xiang ,&nbsp;M. Newsam ,&nbsp;M. Griffiths","doi":"10.1016/j.actaastro.2026.01.037","DOIUrl":"10.1016/j.actaastro.2026.01.037","url":null,"abstract":"<div><div>The intake of an atmosphere-breathing electric propulsion system plays a pivotal role in capturing and collimating atmospheric residuals prior to the propulsion stage. Accurate assessment of intake performance necessitates accounting for rarefied gas dynamics, flow compression, and gas-surface interactions. In this study, the DSMC solver, dsmcFoam, is rigorously validated against fundamental benchmarks, including Clausing empirical cases and comparisons with the PICLas solver. Furthermore, dsmcFoam-dsmcFoam comparison is also conducted and observed deviations between our results and existing dsmcFoam results in the literature highlight the critical importance of careful simulation setup and procedural rigour. A systematic analysis of the simulation workflow, supplemented by additional computational strategies, demonstrates their pronounced impact on intake performance metrics. Furthermore, distinct definitions for efficiency – namely, collection efficiency and transmission efficiency for vacuum, standalone, and integrated configurations – are introduced, establishing a comprehensive framework for evaluating intake performance across varying operational altitudes and surface properties. The findings confirm that (i) dsmcFoam represents a reliable tool for ABEP intake design, providing a foundation for further developments, (ii) a structured and generic simulation procedure tailored for ABEP intakes is essential, and (iii) conventional efficiency metrics for ABEP intakes needs reconsideration for broader applicability and accurate performance evaluation.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 14-31"},"PeriodicalIF":3.4,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146047965","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":"“Getting Things Done” or “Doing the Right Things”? Micro-foundations of Product-Service Strategies in Earth Observation","authors":"Valentina Zancan, Paolo Trucco, Giorgio Locatelli","doi":"10.1016/j.actaastro.2026.01.040","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.01.040","url":null,"abstract":"","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"271 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033432","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":"Feasibility-guaranteed analytical mars landing guidance in hazardous terrains with disturbances","authors":"Yan Wang ,&nbsp;Yaxuan Li ,&nbsp;Xinfu Liu","doi":"10.1016/j.actaastro.2026.01.053","DOIUrl":"10.1016/j.actaastro.2026.01.053","url":null,"abstract":"<div><div>This paper investigates the Mars landing guidance problem in hazardous terrains. Disturbances during landing, including parameter uncertainties and external forces, may cause the guidance problem infeasible, preventing the lander from avoiding the terrains. To ensure a safe landing, it is crucial, though challenging, to maintain the recursive feasibility of the guidance problem in each guidance cycle. To this end, we propose a two-phase guidance framework, where recursive feasibility is considered only in the first phase and the terminal constraints in this phase are significantly relaxed. This turns the recursive feasibility requirement into the assured satisfaction of the terrain avoidance constraint under disturbances in each guidance cycle. The main contribution of this work lies in analytically deriving a feasible control set and proving that, as long as the control command is within this set, the state at the next guidance cycle must be able to reach the required terminal state while satisfying the terrain avoidance constraint. This guarantees the recursive feasibility of the guidance problem, provided it is feasible in the initial time. As a result, guidance commands in the first phase can be generated by the well-known ZEM/ZEV guidance law, and then simply saturated by the derived feasible control set. In the second phase, the terrain avoidance constraint no longer needs to be considered and the ZEM/ZEV guidance law is applied to drive the lander to the desired location with a safe touchdown velocity. Numerical examples demonstrate that the proposed method can ensure recursive feasibility of the guidance problem under disturbances and is capable of achieving meter-level landing accuracy.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 1-13"},"PeriodicalIF":3.4,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033441","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":"Galerkin Lie Group Variational Integrators Developed for Orbit-Attitude Coupled Dynamics near Small Celestial Bodies","authors":"Jinah Lee, Chandeok Park","doi":"10.1016/j.actaastro.2026.01.052","DOIUrl":"https://doi.org/10.1016/j.actaastro.2026.01.052","url":null,"abstract":"","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"50 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033442","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":"Orbit determination and prediction for uncooperative spacecrafts with continuous low-thrust maneuver via piecewise estimation","authors":"Liu Yuan ,&nbsp;Bin Li ,&nbsp;Xin Tian ,&nbsp;Wei Liang ,&nbsp;Peng Lv ,&nbsp;Jizhang Sang","doi":"10.1016/j.actaastro.2026.01.033","DOIUrl":"10.1016/j.actaastro.2026.01.033","url":null,"abstract":"<div><div>The exponential growth of mega-constellation satellites, typified by SpaceX’s Starlink, poses unprecedented challenges for existing space surveillance, particularly when tracking uncooperative spacecrafts executing continuous orbit-raising/deorbiting maneuvers. This situation makes the conventional orbit determination (OD) and prediction (OP) struggle with three critical issues: insufficient observational data, unknown maneuvering parameters, and the cumulative effects of unmodeled thrust. To address these issues, this study proposes a piecewise estimation-based OD method by developing a semi-analytical thrust acceleration (TA) model. The TA model employs time-explicit polynomial expansions with state-dependent coefficients to characterize the continuous low-thrust effect. The OD system integrates a piecewise least-squares estimation algorithm with dynamic compensation, enabling accurate TA resolution within one-day observation windows. Specifically, the OP system incorporates the latest TA estimate to account for the future continuous low-thrust effect. Experiments with sparse radar observations of Starlink satellites demonstrate the effectiveness of the proposed method. The TA estimation errors remain below 0.5% relative to the reference obtained from precise ephemerides. The OP capabilities maintain one-day and two-day position accuracy below 2 and 4 km, respectively, improving by more than 60% compared to the unified OD method. More importantly, the approach exhibits operational robustness, achieving OD convergence with initial TA errors up to 35%. These advantages make the proposed approach a practicable solution for autonomous catalog maintenance of maneuvering spacecraft.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 99-111"},"PeriodicalIF":3.4,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-objective evolutionary optimization for infrared image reconstruction and typical thermal response selection in hypervelocity impact damage detection","authors":"Zhongbao Yan ,&nbsp;Chun Yin ,&nbsp;Xuegang Huang ,&nbsp;Jiuwen Cao ,&nbsp;Yuanhao Zhang","doi":"10.1016/j.actaastro.2026.01.051","DOIUrl":"10.1016/j.actaastro.2026.01.051","url":null,"abstract":"<div><div>The complex damage caused by hypervelocity impact poses significant challenges for spacecraft damage detection. This paper presents a novel method for detecting hypervelocity impact damage in spacecraft based on infrared nondestructive testing, which utilizes transient thermal response data and designs an adaptive classification model based on kernel density estimation to effectively distinguish different types of defect information. Additionally, the paper addresses the issue of extracting typical transient thermal responses from various defect types and constructs a multi-objective optimization function based on intraclass representativeness and interclass distinctiveness. The proposed multi-objective evolutionary optimization algorithm, combined with the <span><math><mi>α</mi></math></span>-shape method, neural networks, and vertical distance measures, dynamically adjusts the weight vectors to optimize the distribution of solutions and balance convergence and diversity, resulting in higher quality typical transient thermal responses. Experimental results validate the effectiveness of the proposed method on real hypervelocity impact specimens, successfully obtaining defect images of different types.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 46-60"},"PeriodicalIF":3.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033456","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 risk on the ground and in the airspace posed by uncontrolled re-entries: Should the growth observed in recent years be considered worrying?","authors":"Carmen Pardini,&nbsp;Luciano Anselmo","doi":"10.1016/j.actaastro.2026.01.049","DOIUrl":"10.1016/j.actaastro.2026.01.049","url":null,"abstract":"<div><div>Between 2010 and 2024, the risk posed by uncontrolled orbital re-entries of spacecraft, upper stages, and large debris to people on the ground and commercial aviation was assessed using realistic models for the number and casualty area of surviving fragments, as well as for the latitudinal distribution of population and air traffic. Each re-entered object was analyzed individually, taking into account its dry mass and actual orbital inclination. Furthermore, the effects of complete atmospheric demise were evaluated for objects with a re-entry dry mass of less than 300 kg. The nominal estimates obtained with the various approaches are expected to be affected by uncertainties of a factor of 2 or 3. Throughout the decade from 2010 to 2019, the risk levels remained relatively stable. However, from 2020 onward, there was a significant increase in risk, primarily due to the intensification of space activities. In 2024, the estimated collective casualty probability for people on the ground ranged between the nominal values of 5 % and 10 %, depending on the assumptions and models adopted. In the same year, the likelihood of a commercial aircraft being struck by re-entry debris capable of causing catastrophic failure was assessed to be between the nominal values of 3.7 × 10⁻⁵ and 1.5 × 10⁻⁴. This equates to an average of one aircraft impact every 27,000–6700 years, respectively. For passengers aboard commercial aircraft, the nominal collective casualty probability ranged from 0.44 % to 1.82 %. Although the overall re-entry risk remains relatively low, a notable upward trend was observed between 2019 and 2024. Specifically, the number of uncontrolled re-entries increased by a factor of 7, the cumulative re-entered mass increased by a factor of 3, the ground casualty probability rose by a factor of 3–4, and the casualty probability for commercial aircraft passengers increased by a factor of 3–6. This marked escalation highlights the urgent need for timely and effective mitigation strategies to prevent risks from exceeding thresholds deemed unacceptable from both operational and societal perspectives.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"242 ","pages":"Pages 312-327"},"PeriodicalIF":3.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033944","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":"Hypervelocity perforation of thin films applicable to debris detection in Low Earth Orbit","authors":"M.J. Burchell,&nbsp;L.A. Alesbrook,&nbsp;M. van Ginneken,&nbsp;P.J. Wozniakiewicz","doi":"10.1016/j.actaastro.2026.01.050","DOIUrl":"10.1016/j.actaastro.2026.01.050","url":null,"abstract":"<div><div>The growth in the number of satellites in Low Earth Orbit, coupled with the possibility of their catastrophic disruption, may lead to more orbital debris, which in turn has increased the risk of damage to spacecraft arising from impacts by small pieces of debris. There is thus an urgent need to monitor the small particle population in Low Earth Orbit, using a new generation of dust detectors. Various designs are in preparation, and several use the principle of observing particles via their impact penetration of thin films. Previously, most laboratory studies of penetration of thin films have used spherical impactors for ease. However, these are not representative of the shapes of orbital debris. Accordingly, here, impacts are reported at 5 km s⁻¹, by various shaped projectiles (sizes typically 0.5–2 mm) on thin (12.5 μm thick) Kapton films. The shapes used were spheres, rods, cubes and platelets, and represent a selection of the shapes present in the orbital debris population that arises from catastrophic disruption of spacecraft. The size and shape of the holes in the Kapton arising from the impacts, are shown to reflect the size and cross-sectional area of an impactor as it passes through the film; even the presence of angular corners in the impactors can be seen in the holes. However, due to the variable aspect of an individual impactor presented to the film during an impact, identification of the exact 3-dimensional shape cannot be obtained from the 2-dimensional hole. Nevertheless, with minor exceptions it is possible to separate more spherical (i.e., natural dust) impactors from the other shapes (i.e. variously shaped anthropogenic debris).</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 73-90"},"PeriodicalIF":3.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A unified framework for compliant control and trajectory planning in robotic in-orbit assembly","authors":"Qiming Ren ,&nbsp;Minghe Shan","doi":"10.1016/j.actaastro.2026.01.029","DOIUrl":"10.1016/j.actaastro.2026.01.029","url":null,"abstract":"<div><div>Robotic In-Orbit Assembly (R-IOA) is a key technology for the construction of large-scale space infrastructure. A significant challenge in this field is the precise docking of modular components, particularly those with complex interfaces. To address this, safety must be considered at both the control and planning levels. At the control level, traditional compliant control strategies show poor adaptability to complex contact and often face challenges in explicitly enforcing physical limitations, such as joint position and torque bounds. Furthermore, while compliant control can effectively manage steady-state contact forces, it is fundamentally limited in mitigating the initial transient impact. This peak force is predominantly determined by the pre-impact velocity, a parameter dictated by the trajectory planner. Conventional planners, however, often generate dynamically infeasible trajectories using decoupled methods that violate the kinematic consistency of rigid-body motion, and they are generally limited in their ability to strictly enforce velocity constraints. To address these dual challenges through an integrated approach, this paper proposes a unified safety framework. This framework combines comprehensive enhancements at both the planning and control layers. At the planning level, a time-optimal trajectory generator operating on the SE(3) manifold produces motions that are dynamically feasible by construction. This ensures that velocity constraints are strictly enforced to proactively minimize impact forces and that the trajectory respects the natural kinematics of rigid-body motion. At the control level, we introduce a Hierarchical Quadratic Programming based Adaptive Controller (HQP-AC). It reformulates compliant interaction as a constrained optimization problem to guarantee the strict enforcement of all hardware safety limits while adaptively managing the steady-state interaction. The effectiveness of the proposed approach was demonstrated through simulations of a representative docking scenario. Compared to a classical impedance controller with decoupled trajectory planning, the proposed framework reduces peak axial contact forces by 49% and steady-state contact forces by 30%, and successfully prevents the catastrophic joint limit violations observed in the baseline method. Furthermore, it achieves a final lateral position error of 0.18<!--> <!-->mm and an orientation error of 1.08°, representing a significant improvement in docking accuracy.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 32-45"},"PeriodicalIF":3.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033440","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":"Sun sensor calibration algorithms: A systematic mapping and survey","authors":"Michael Herman,&nbsp;Olivia J. Pinon Fischer,&nbsp;Dimitri N. Mavris","doi":"10.1016/j.actaastro.2025.12.053","DOIUrl":"10.1016/j.actaastro.2025.12.053","url":null,"abstract":"<div><div>Attitude sensors determine the spacecraft attitude through the sensing of an astronomical object, field or other phenomena. The Sun and fixed stars are the two primary astronomical sensing objects. Attitude sensors are critical components for the survival and knowledge improvement of spacecraft. Of these, sun sensors are one of the most common and important sensors for small satellite attitude determination. The sun sensor measures the Sun vector in spacecraft coordinates. The sun sensor calibration process is particularly difficult due to the complex nature of the uncertainties involved. The uncertainties are small, difficult to observe, and vary spatio-temporally over the lifecycle of the sensor. In addition, the sensors are affected by numerous sources of uncertainties, including manufacturing, electrical, environmental, and interference sources. This motivates the development of advanced calibration algorithms to minimize uncertainty over the sensor lifecycle and improve accuracy. Although modeling and calibration techniques for sun sensors have been explored extensively in the literature over the past two decades, there is currently no resource that consolidates and systematically reviews this body of work. The present review proposes a systematic mapping of sun sensor modeling and calibration algorithms across a breadth of sensor configurations. It specifically provides a comprehensive survey of each methodology, along with an analysis of research gaps and recommendations for future directions in sun sensor modeling and calibration techniques.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 112-148"},"PeriodicalIF":3.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033458","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}