Acta Astronautica最新文献

{"title":"Autonomous optical flow-based initial orbit determination","authors":"Willem Oliveira","doi":"10.1016/j.actaastro.2026.01.054","DOIUrl":"10.1016/j.actaastro.2026.01.054","url":null,"abstract":"<div><div>The navigation algorithms proposed in the literature to achieve pinpoint landing for space exploration missions require initialization with state estimates from ground. This limits the missions that can be accomplished and significantly increases operation costs. This paper introduces an orbit determination (OD) algorithm, which can be used to autonomously initialize existing terrain absolute navigation (TAN) algorithms with pinpoint landing accuracy. Visual data is collected over the course of two orbit periods. This data is used to estimate the Keplerian orbit parameters of the trajectory. The estimated orbit parameters are used to initialize a crater-based TAN system independently from ground telemetry, thus providing a fully autonomous navigation system with pinpoint landing capability.</div><div>An extensive test campaign was performed using both simulated measurements and rendered images. The algorithm was shown to successfully enable TAN initialization.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 237-250"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072616","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":"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":"2026-06-01","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":"A 698 nm laser system for excitation of fluorescent quantum light sources on a CubeSat mission","authors":"Sven Schwertfeger ,&nbsp;Elisa Da Ros ,&nbsp;Marcel Bursy ,&nbsp;Andreas Wicht ,&nbsp;Daniel Pardo ,&nbsp;Ankush Sharma ,&nbsp;Subash Sachidananda ,&nbsp;Alexander Ling ,&nbsp;Markus Krutzik","doi":"10.1016/j.actaastro.2026.01.060","DOIUrl":"10.1016/j.actaastro.2026.01.060","url":null,"abstract":"<div><div>This manuscript reports on the development and qualification of an ECDL-based, fiber-coupled laser system at a wavelength of <span><math><mrow><mi>λ</mi><mo>=</mo><mn>698</mn></mrow></math></span> nm for space applications. We designed and developed the optical and mechanical configuration, along with the laser driving and thermal management electronics, to meet space compatibility requirements. Validation tests were conducted on off-the-shelf components to assess their suitability for satellite deployment. The final system integrates all components into a compact design optimized for CubeSat platforms.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 91-98"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal analysis of control moment gyroscopes based on the thermal network method","authors":"Lei Chen ,&nbsp;Zhangfan Xu ,&nbsp;Song Pan ,&nbsp;Huafeng Li","doi":"10.1016/j.actaastro.2026.01.065","DOIUrl":"10.1016/j.actaastro.2026.01.065","url":null,"abstract":"<div><div>Control moment gyroscopes serving as high-power attitude actuators for large spacecraft require sustained lubrication performance of their high-speed bearings to ensure long-term operation. A critical challenge arises from the temperature-dependent release rate of lubricant stored in oil reservoirs, combined with structural constraints that impede direct temperature measurement at key bearing nodes. To address this issue, this study develops a thermal network modeling methodology for control moment gyroscopes that enables comprehensive and precise temperature estimation across all critical components. Experimental validation via thermal equilibrium tests demonstrates strong agreement between the measured and simulated temperatures (with an error coefficient of less than 12 %). The verified thermal network model provides an effective theoretical framework for the on-orbit thermal management and failure early warning of control moment gyroscopes, thereby enhancing operational reliability and extending lifespan. This methodology offers significant value for precision thermal control in advanced aerospace instrumentation systems.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 162-171"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal propellant management devices for CubeSat cold gas propulsion","authors":"Hugh Chen,&nbsp;Samuel T. Hart,&nbsp;Álvaro Romero-Calvo","doi":"10.1016/j.actaastro.2026.01.057","DOIUrl":"10.1016/j.actaastro.2026.01.057","url":null,"abstract":"<div><div>CubeSat cold-gas propulsion increasingly relies on two-phase, self-pressurizing propellants stored in conformal tanks. However, state-of-the-art propellant management strategies for these systems result in significant inefficiencies in volume or power management, limiting the total <span><math><mi>Δ</mi></math></span>V budget and the mission lifetime. These challenges highlight the need for a more compact propellant management approach. The VAporization for PrOpellant Repositioning (VAPOR) experiment investigates the feasibility of repositioning an ullage gas bubble of R-236fa using thermally-induced phase change in various propellant management devices (PMDs). These devices utilize a heat source to vaporize propellant near the outlet, inducing pressure-driven bubble condensation in colder regions of the tank. Capillary structures are integrated to retain vapor near the heater and promote bubble coalescence, facilitating extraction and routing to thrusters. Building upon iterative designs across two parabolic flight campaigns, six thermocapillary PMDs are evaluated, culminating in three thermal start basket architectures. Patch heater PMDs initiate ullage generation in under 1 s and sustain the highest boiling rates, whereas sponge-based start baskets exhibit an average initiation time of <span><math><mrow><mn>6</mn><mo>.</mo><mn>9</mn><mo>±</mo><mn>1</mn><mo>.</mo><mn>3</mn></mrow></math></span> s with more modest ullage generation. All capillary structures successfully capture the generated vapor. Collectively, results establish thermocapillary PMDs as a compact alternative to conventional two-tank systems for CubeSat cold-gas propulsion.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 291-304"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089678","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":"Electron-beam lunar dust mitigation under solar-like vacuum ultraviolet illumination","authors":"Josef L. Richmond ,&nbsp;Joshua R. Machacek ,&nbsp;Christine Charles ,&nbsp;Roderick W. Boswell","doi":"10.1016/j.actaastro.2026.01.070","DOIUrl":"10.1016/j.actaastro.2026.01.070","url":null,"abstract":"<div><div>Electrostatic dust-cleaning with low-energy electron beams is a promising countermeasure against regolith contamination expected during sustained Lunar surface operations. Laboratory demonstrations, however, typically neglect the vacuum ultraviolet (VUV) component of solar radiation that dominates photoelectric charging on the Lunar dayside. Here we quantify, for the first time, the influence of a sun-like VUV spectrum on electron-beam-driven dust removal from spacesuit fabrics. Beta-cloth samples deliberately contaminated with OPRLJSCN Lunar Mare simulant were exposed to (i) a thermionic electron beam (<span><math><mrow><mn>30</mn><mspace></mspace><mi>μ</mi><mi>A</mi></mrow></math></span> cm⁻², <span><math><mo>≤</mo></math></span> 120 eV) and (ii) VUV fluxes generated by a mixed-gas 13.56 MHz RF plasma lamp that reproduces the solar spectrum in the 115–160 nm range. Three illumination regimes were tested: no VUV (dark), lunar-equivalent VUV (0.3 mW cm⁻²), and elevated VUV (5 mW cm⁻²). The inclusion of VUV photons significantly lowered the threshold beam current density and energy to initiate dust mobilisation, with the filament bias needed to initiate lift-off falling from –93 V (dark) to –52 V (lunar-equivalent VUV) and –37 V (elevated VUV), while the required beam current density dropped by up to two orders of magnitude. Dust removal efficiency improved from 76% after 72 s (dark) to 85% in 48 s (lunar VUV) and 95% in only 9 s under strong illumination. Furthermore, the mean particle size reduced with increasing VUV flux from <span><math><mrow><mn>29</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> (brushing) to <span><math><mrow><mn>16</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> (dark). Results indicate that the Solar VUV can be exploited to reduce power requirements and cleaning time for electron-beam dust mitigation, and motivates inclusion of realistic illumination environments in future mitigation trials.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 338-345"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134799","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":"Dynamic Cone Penetration Test in Lunar Highlands Regolith Simulant","authors":"Kārlis Šļumba,&nbsp;Brendan T. Scott,&nbsp;Mark B. Jaksa","doi":"10.1016/j.actaastro.2026.01.055","DOIUrl":"10.1016/j.actaastro.2026.01.055","url":null,"abstract":"<div><div>It is essential to understand the geotechnical properties of the ground before anything can be built on Earth, the Moon, or elsewhere. The cone penetrometer is a simple but very important instrument that yields quantitative and qualitative information about the geotechnical properties of the material. Quantitative information is the penetration resistance from which density and layering can be inferred, and ground improvement can be evaluated. Qualitative information includes identifying layering and inhomogeneities, as well as the existence of boulders.</div><div>Cone penetrometers are often proposed for space missions (e.g., Beagle 2, InSight, Philae) and were even used by Apollo astronauts. All cone penetrometers that have been used extra-terrestrially so far have either experienced difficulties with penetration or were designed to penetrate less than 100 mm deep and stop before encountering any meaningful resistance. An optimally developed dynamic cone penetrometer might work better because it requires less reaction force.</div><div>This research consists of the development of a bespoke dynamic cone penetrometer with variable cone size and hammering energy. Further, this instrument is tested in a large-scale regolith compaction chamber with lunar highlands regolith simulant LHS-1E at a wide range of densities to find the optimal setup where penetration captures enough data by moving slowly but also does not stagnate. Results from dynamic cone penetration tests at many different densities are compared and successfully correlated to cone penetration and nuclear density gauge test results. Calculated coefficients allow for the conversion directly between dynamic and regular cone penetration tests at any density, which shows promise for greater use of dynamic cone penetrometers in lunar applications.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 172-188"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146047959","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":"Study on the mechanism of supersonic diverter flow","authors":"Xi Wang ,&nbsp;Gang He ,&nbsp;Yan-ping Tian ,&nbsp;Yu-xin Zhao ,&nbsp;Qian-cheng Wang ,&nbsp;Yi-long Zhao","doi":"10.1016/j.actaastro.2026.01.044","DOIUrl":"10.1016/j.actaastro.2026.01.044","url":null,"abstract":"<div><div>The boundary layer on the surface of supersonic and hypersonic vehicles exerts a significant influence on inlet performance. The diverter is widely utilized to expel the boundary layer directly, thereby enhancing the inlet’s efficiency. This paper establishes a simplified research model of the diverter and investigates the characteristics and mechanisms of the complex three-dimensional flow both within and external to the diverter using oil-flow visualization, pressure measurement, and Nanoparticle-based Planar Laser Scattering (NPLS) techniques. The results indicate that the flow within the diverter exhibits three states: choked, critical, and unchoked. In the choked and critical states, the separation line on the flat plate forms a ”bow” shape, and secondary separation phenomena are observed. In contrast, the separation zone in the unchoked state exhibits quasi-conical flow characteristics. Additionally, as the diverter height increases, the separation angle of the separation line increases and approaches that of swept shock wave/boundary layer interactions under the same deflection conditions. Furthermore, with an increase in the diverter height, the flow state within the diverter transitions from the choked state to the critical state, and ultimately to the unchoked state. Regarding the diverter as two symmetric, back-to-back side-compression inlets, the inviscid effects of the diverter height increase are examined through the inlet starting theory. The results shows that the inviscid factor plays a limited role in the diverter’s flow-passing capability. In future, the viscous effects of the diverter height increase would be examined with high-precision simulation results.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 315-325"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072609","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":"Top 50 List for 2025","authors":"Darren McKnight ,&nbsp;Erin Dale ,&nbsp;Joe Cassady ,&nbsp;Andy Ratcliffe ,&nbsp;Satomi Kawamoto ,&nbsp;Alessandro Rossi ,&nbsp;Dmitriy Grishko","doi":"10.1016/j.actaastro.2025.12.035","DOIUrl":"10.1016/j.actaastro.2025.12.035","url":null,"abstract":"<div><div>The growth of orbital debris in number and mass in low Earth orbit (LEO) has been a subject of analysis for decades. The global community established the 25-yr debris mitigation rule 20–25 years ago and at that time many started assembling long lists of number, mass, and nationality of abandoned hardware. In 2020, a team of 19 experts from 13 countries assembled to create a definitive list of 50 objects that would most likely directly drive debris growth in LEO. This list was provided as a “priority list” for active debris removal (ADR) operations. Since 2020, continued accumulation of derelict objects coupled with the rapid increase of operational satellites has occurred. This combination has motivated the authors to update the 2020 Top 50 List. The new list considers (a) aggregate collision risk (i.e., probability of collision x consequence) since January 1, 2022, (b) orbital persistence of fragments (if a collision occurs), (c) proximity to existing altitudes where aggregate statistical risk of the population is the largest (meaning clusters centered around 775 km, 840 km, 1000 km, and 1400 km), (d) mass of object, and (e) coupling between removing objects on the list.</div><div>The paper is enabled through the application of new analytic tools created by LeoLabs based on empirical observations of close approaches in LEO merged with open-source tagging of objects in the public catalogue with known masses. It is important to note the coauthors abide by the philosophy that many viable models can be used to derive the top 50 objects to be removed from LEO. The benefit of the current approach applies a team approach to adjusting filters to a single model; however, the implication is not that this model is the only way to select the top 50 objects. In essence, one of the most critical aspects of any attempt to identify the objects whose retrieval will decrease the debris-generating potential in LEO is to identify key features of objects such as mass, probability of collision (especially with other massive objects), altitude, etc. A comparison of the 2020 Top 50 List and the new 2025 Top 50 List is provided to illuminate key lessons for debris hazard evolution and to motivate operationalization of ADR.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 346-357"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089657","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":"Mitigating satellite trails through retroreflective coatings: A proposal for preserving the night sky","authors":"Tobias Degen ,&nbsp;John C. Barentine ,&nbsp;Gyula I.G. Józsa ,&nbsp;Thomas Walter ,&nbsp;Jacqueline Degen","doi":"10.1016/j.actaastro.2026.01.042","DOIUrl":"10.1016/j.actaastro.2026.01.042","url":null,"abstract":"<div><div>We propose retroreflective coatings on satellites to mitigate sunlight reflections that cause disruptive trails in astronomical observations. By redirecting sunlight back toward the Sun, this approach reduces apparent brightness without creating thermal burdens, while also enhancing satellite tracking capabilities—offering a timely and practical pathway to address impacts from growing satellite constellations.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"243 ","pages":"Pages 202-206"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014254","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}