Advances in Space Research最新文献

{"title":"An SPH model reconstruction framework with fragment mapping method for multiplate structure hypervelocity impact simulation","authors":"Xu Cao ,&nbsp;Jianqiu Zhou ,&nbsp;Huadong Xu ,&nbsp;Di Song ,&nbsp;Changqing Miao","doi":"10.1016/j.asr.2025.03.047","DOIUrl":"10.1016/j.asr.2025.03.047","url":null,"abstract":"<div><div>Smoothed Particle Hydrodynamics (SPH) method is widely used in hypervelocity impact analysis, but it is computationally inefficient for common multiplate structures, such as multi-shock, mesh double-bumper, and stuffed shields. To improve the efficiency and accuracy of the SPH method, a reconstruction framework is proposed, including a fragment identification method, a fragment mapping method, and a sequential modeling and simulation approach. In the reconstruction framework, the total impact simulation of a multiplate structure consisting of <em>n</em> plates is decomposed into <em>n</em> individual impacts on each plate. To reduce the computation for each impact, a fragment identification method and a fragment mapping method are developed. Fragments generated from the impact with the <em>i</em>-th plate (<em>i</em> &lt; <em>n</em>) are identified and mapped to the near positions in front of the (<em>i</em> + 1)-th plate using a linear motion algorithm. To reduce the total computation time, a sequential modeling and simulation approach is introduced, only the fragments from the <em>i</em>-th impact and the SPH model of the (<em>i</em> + 1)-th plate of the multiplate structure are reconstructed and simulated sequentially, excluding the other plates. The results show a significant improvement in computational efficiency compared to the traditional SPH method. For a three-layer structure with a 100 mm spacing, the efficiency is 59.2 times larger, while for a double-layer structure with a 350 mm spacing, the efficiency is 201.74 times larger. Moreover, the interactions between fragments are considered in the reconstruction framework, thereby the accuracy of the simulation is also improved.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 8140-8157"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Debiasing of two-line element sets for batch least squares pseudo-orbit determination in MEO and GEO","authors":"Max I. Hallgarten La Casta,&nbsp;Davide Amato","doi":"10.1016/j.asr.2025.03.046","DOIUrl":"10.1016/j.asr.2025.03.046","url":null,"abstract":"<div><div>The availability of accurate and timely state predictions for objects in near-Earth orbits is becoming increasingly important due to the growing congestion in key orbital regimes. The Two-Line Element Set (TLE) catalogue remains, to this day, one of the few publicly-available, comprehensive sources of near-Earth object ephemerides. At the same time, TLEs are affected by measurement noise and are limited by the low accuracy of the SGP4 theory, introducing significant uncertainty into state predictions. Previous literature has shown that filtering TLEs with batch least squares methods can yield significant improvements in long-term state prediction accuracy. However, this process can be highly sensitive to TLE quality which can vary throughout the year. In this study, it is shown that either extended-duration fit windows of the order of months, or the removal of systematic biases in along-track position prior to state estimation can produce significant reductions in post-fit position errors. Simple models for estimating these systematic biases are shown to be effective without introducing the need for high-complexity Machine Learning (ML) models. Furthermore, by establishing a TLE-based error metric, the need for high accuracy ephemerides is removed when creating these models. For selected satellites in the Medium Earth Orbit (MEO) regime, post-fit position errors are reduced by up to 80%, from approximately 5 km to 1 km; meanwhile, for selected satellites in the Geostationary Earth Orbit (GEO)/Geosynchronous Earth Orbit (GSO) regime, large oscillations in post-fit position error can be suppressed.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 10","pages":"Pages 7259-7289"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neural combinatorial optimization for multi-rendezvous mission design","authors":"Antonio López Rivera ,&nbsp;Marc Naeije","doi":"10.1016/j.asr.2025.03.050","DOIUrl":"10.1016/j.asr.2025.03.050","url":null,"abstract":"<div><div>Optimal solutions to spacecraft routing problems are essential for space logistics activity such as Active Debris Removal (ADR), which addresses the growing threat of space debris. This research investigates the effectiveness of Neural Combinatorial Optimization (NCO) methods for the autonomous planning of low-thrust, multi-target ADR missions, an instance of the Space Traveling Salesman Problem (STSP). An autoregressive, attention-based routing policy was trained to solve 10-transfer ADR routing problems using REINFORCE, Advantage Actor-Critic, and Proximal Policy Optimization. A hyperparameter sensitivity analysis identified embedding dimension and the number of encoder layers as the critical factors influencing model performance, while an ablation study found the attention-based encoder to be the most critical architectural component of the policy. The trained policy was evaluated on 10-, 30-, and 50-transfer scenarios based on the Iridium 33 debris cloud, comparing its performance to a baseline provided by a novel ADR STSP routing heuristic (Dynamic RAAN Walk, DRW) and near-optimal benchmarks obtained via Heuristic Combinatorial Optimization (HCO). In missions with 10 transfers, the NCO policy achieved a mean optimality gap of 32%, outperforming DRW. However, performance degraded significantly in scenarios with 30 and 50 transfers, suggesting limited generalization to larger problems. A hyperparameter search further revealed that the performance of the NCO model considered in this work improves asymptotically with its size. Exposure to greater numbers of training scenarios did not yield significant performance gains. This work demonstrates that NCO methods can be effective for the autonomous planning of ADR missions with a limited number of targets, but face scalability and generalization challenges in more complex scenarios.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 10","pages":"Pages 7306-7326"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling aerodynamic drag of a very low earth orbit 1U CubeSat utilising a Boltzmann-BGK approach","authors":"Joseff Parke Sturrock,&nbsp;Ben Evans,&nbsp;Zoran Jelic","doi":"10.1016/j.asr.2025.03.055","DOIUrl":"10.1016/j.asr.2025.03.055","url":null,"abstract":"<div><div>The aerodynamic drag of a 1U CubeSat at various Very Low Earth Orbit (VLEO) altitudes and conditions have been investigated utilising an in-house Boltzmann-BGK solver. This region of space has numerous benefits, however significant drag can lead to short satellite lifespans. The analyses focus on determining drag coefficients, as well as absolute drag values. Flow fields are illustrated. Monoatomic oxygen number density ratios on exposed surfaces were presented to help guide corrosion analysis. Material properties for satellite surface coatings have been analysed, including drag reduction performance. All atmospheric parameters were sourced from NASA’s NRLMSIS 2.0 atmospheric model. Altitudes investigated range from 50 km to 500 km. Periods of solar minima and maxima, seasonal variances and local day/night cases were investigated. Drag coefficients were evaluated and compared with corresponding Knudsen numbers. Although there are significant variations of the drag coefficient (C_D) at very low altitudes, higher altitudes produced consistent values. Two CubeSat geometric orientations were studied, one settled to a consistent C_D of around 1.24 for higher altitudes, while the other case settled to a C_D of 1.60. The material property of specularlity was found to have a considerable impact on drag coefficients – altering this parameter could lead to significantly higher drag coefficients, in some cases exceeding values of 2.0. The drag coefficients computed can be coupled with other existing models to determine satellite lifespan, as well as to estimate expected drag at various orbital altitudes. This will be insightful for determining thrust values of drag compensation systems, serving to extend the lifespan of VLEO operating satellites.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 10","pages":"Pages 7610-7623"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attention based multi-level and multi-scale convolutional network for PolSAR image classification","authors":"Maryam Imani","doi":"10.1016/j.asr.2025.03.051","DOIUrl":"10.1016/j.asr.2025.03.051","url":null,"abstract":"<div><div>Due to presence of heterogenous regions with materials and objects with different shapes and sizes in natural scenes, there are various contextual information in polarimetric synthetic aperture radar (PolSAR) images, which can be highlighted in the low-, medium-, or high-level features in different scales. To handle these challenges, the multi-scale and multi-level attention learning (MMAL) network is proposed for PolSAR image classification. A convolutional neural network (CNN) with six convolutional layers is introduced for hierarchical extraction of local contextual features in multiple levels. The cross-attention is used to find the relationships among low-level and high-level features and also among medium-level and high-level features. This process is repeated in multiple scales. Finally, the attention based multi-level and multi-scale features are fused to provide the classification map. An ablation study is done in several PolSAR images to show impact of different parts of the proposed network, which shows the superior efficiency of feature fusion in multiple levels and scales with taking to account the cross-attention among low–high and medium–high levels. The proposed MMAL network generally provides improved classification results compared to a CNN with the same structure and settings. For example, for the AIRSAR Flevoland image containing 15 class, with using 100 training samples per class, the overall accuracy of 96.15% with 2.74% increment with respect to the basic CNN is achieved where this improvement is statistically significant in term of the McNemars test. Moreover, the proposed method shows improvement compared to several state-of-the-art PolSAR classification methods.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7971-7986"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precise real-time navigation of the LEO satellite enhanced by BDS-3 PPP-B2b service","authors":"Xuewen Gong ,&nbsp;Wanwei Zhang ,&nbsp;Aili Zhao ,&nbsp;Shuaihe Gao ,&nbsp;Fuhong Wang ,&nbsp;Jingkui Zhang ,&nbsp;Song Xie ,&nbsp;Guodong Feng ,&nbsp;Zaichun Yang","doi":"10.1016/j.asr.2025.03.049","DOIUrl":"10.1016/j.asr.2025.03.049","url":null,"abstract":"<div><div>For the real-time navigation of LEO satellites based on GNSS, the achievable real-time orbit accuracy is generally limited by the quality of GNSS broadcast ephemeris. In this paper, the correction data released by the BDS-3 PPP-B2b service are introduced to correct the broadcast ephemeris of GPS and BDS-3 satellites, aiming to enhance the real-time orbit accuracy of LEO satellites. Experimental analysis reveals that the errors in the orbits and clock offsets of GPS and BDS-3 satellites are significantly reduced after applying PPP-B2b corrections. Considering that PPP-B2b corrections are only available within the Asia-Pacific region, centered around China, for those epochs where some of the tracked GPS/BDS-3 satellites have access to PPP-B2b corrections while others must rely solely on broadcast ephemerides, an improved measurement update strategy (IMUS) is proposed. This strategy excludes the observations of those GPS/BDS-3 satellites relying on broadcast ephemeris from the measurement update of real-time navigation filtering when the number of satellites available for PPP-B2b reaches a certain threshold. Real-time navigation experiments are conducted on the LT-1A satellite separately using single GPS L1/L2 and single BDS-3 B1C/B2a observations. The results demonstrate that, regardless of whether it is based on GPS or BDS-3, the improvement in real-time orbit accuracy achieved by IMUS after applying PPP-B2b corrections is slightly greater than that achieved by the conventional measure update strategy (CMUS), which treats all tracked satellites equally without differentiation. This indicates that the proposed IMUS could further enlarge the enhancement effect of PPP-B2b corrections on LEO real-time navigation. With the application of PPP-B2b corrections and IMUS, the real-time orbit accuracy of the LT-1A satellite, based on GPS and BDS-3, improves by more than 10% and 8%, respectively, over the entire orbital arc compared to using broadcast ephemeris alone. If only considering the arcs within the Asia-Pacific region, the improvement percentages rise to over 24% and 11% with GPS and BDS-3, respectively. This has fully demonstrated that the secure and free PPP-B2b corrections present an excellent option for achieving more accurate real-time navigation for these LEO satellites equipped with GPS/BDS-3 receivers.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 10","pages":"Pages 7003-7019"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of tethered towing system after net capture","authors":"Jia Guo ,&nbsp;Zhaojun Pang ,&nbsp;Weiliang Zhu ,&nbsp;Jiyue Si ,&nbsp;Zhonghua Du","doi":"10.1016/j.asr.2025.03.053","DOIUrl":"10.1016/j.asr.2025.03.053","url":null,"abstract":"<div><div>The characteristics of a net-tether assembly differ significantly from those of a single tether. The tethered towing system is usually modeled as a single tether. This reduces the reliability. This study establishes a net-tether model that accounts for the flexibility, collisions, and friction inherent in the net. The actual net closure process is simulated to create the initial state of the tethered towing system. The impact of the net on the system’s characteristics is examined. Dynamic parameters of the tethered towing system with a space net are inferred from observational data. Simulation results indicate that the tension in the net-tether model approximately follows a linear relationship with both the change in length and the rate of length change. Additionally, the space net enhances the damping of the tethered towing system. The ratios of axial stiffness and damping coefficient are found to approximate a power function of the size ratio between the net-tether model and the traditional single-tether model, providing a means to correct the traditional single-tether model.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 8158-8173"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preface: Science and applied research with small satellites","authors":"Loren C. Chang,&nbsp;Margaret Ann Shea Guest Editors","doi":"10.1016/j.asr.2025.03.028","DOIUrl":"10.1016/j.asr.2025.03.028","url":null,"abstract":"","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 9","pages":"Pages 6571-6573"},"PeriodicalIF":2.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term ocean tidal parameters estimated from high-rate buoy GNSS data","authors":"Zhifan Yan ,&nbsp;Jinyun Guo ,&nbsp;Maosheng Zhou ,&nbsp;Jingwen Zong","doi":"10.1016/j.asr.2025.03.045","DOIUrl":"10.1016/j.asr.2025.03.045","url":null,"abstract":"<div><div>Ocean tides are significant factors affecting sea surface fluctuations and changes in ocean circulation. Real-time and accurate estimation of tidal parameters is crucial. This paper presents a convenient, fast, accurate, and low-cost method for short-term tidal parameter estimation. The methodology utilizes kinematic Precise Point Positioning (PPP) to determine the height of Global Navigation Satellite System (GNSS) antennas mounted on buoys, integrating the XGM2019e_2159 model and wavelet analysis for baseline transformation and denoising. This process yields the orthometric height sequence of the measurement point’s water level. Subsequently, harmonic analysis is employed to estimate ocean tidal parameters over periods of 16, 8, and 4 days. In addition, the 16-day period ocean tidal parameters are used to predict water levels. Finally, the results are compared with the pressure tide gauge, the FES2022 model and the EOT20 model, indicating that the ocean tidal parameters and predicted water levels closely match the reference values, with differences in amplitudes and phases within ± 5 cm and ± 8° for the 8-day and 4-day periods. This demonstrates that the proposed method effectively reflects short-term tidal information and characteristics.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7960-7970"},"PeriodicalIF":2.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cooperative three-satellite methodology for space target detumbling","authors":"Tianxiao Xu,&nbsp;Weilin Wang,&nbsp;Hua Chai,&nbsp;Qiangqiang Xu","doi":"10.1016/j.asr.2025.03.048","DOIUrl":"10.1016/j.asr.2025.03.048","url":null,"abstract":"<div><div>Excessive rotation speeds of malfunctioning satellites in space complicate target capture and on-orbit servicing. Satellite formation flying, an advanced technology, offers a solution for detumbling tumbling targets. This paper introduces a novel detumbling methodology involving three cooperative satellites and proposes a successive detumbling strategy. Two service satellites are employed to dampen the nutation angle, while a third satellite is utilized to reduce the self-spin angular velocity. By analyzing the effects of torque applied in different directions, the constraints for applying detumbling torques are derived. Specific torque control laws are designed based on integral sliding mode surface functions for despinning, and pulse-type torque control is used for nutation damping. Numerical simulation results demonstrate that the proposed methodology effectively reduces the angular velocity of the tumbling target and exhibits robustness.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 10","pages":"Pages 7290-7305"},"PeriodicalIF":2.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}