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ABSTRACT This review analyzes the integration, functionality, and regulatory environment of unmanned aerial vehicles. In this review, the role of drone technologies with advanced payloads, Red-Green-Blue, and infrared sensors to revolutionize the process of surveying, inspection, and safety monitoring by providing extremely high accuracy in real-time spatial data delivery is considered. The technologies are essential in increasing productivity, minimizing expenses, and decision-making in project management. Other than the technical capability, the paper discusses the international regulatory frameworks and governance models developed by agencies, including the Federal Aviation Administration, the European Union Aviation Safety Agency, the Directorate General of Civil Aviation, and the International Civil Aviation Organization. Even though such systems guarantee the security of the airspace and responsibility of the operators, the analysis indicates that the operations of UAVs between countries remain cumbersome as the loopholes continue to persist. The economic analysis shows that there is a high return on investment in the form of less time spent in the survey, lower labor expenses, and better safety results. Further research should be oriented to artificial intelligence-related data analytics, autonomous UAV swarm control, and automatic connection to building information modelling to allow real-time monitoring of the project and predicting its maintenance requirements.

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ABSTRACT Establishing a permanent and sustainable human presence on the Moon has long been one of humanity’s most ambitious goals. The Moon is continuously exposed to ionizing radiation from the Sun and deep space, rendering it an extreme environment that poses significant radiological risks to future human exploration missions. Accurate radiation dosimetry is essential to ensure astronaut safety. This study aimed to assess the current state of research on radiation dosimetry for potential lunar environments and bases. A bibliometric analysis was conducted based on the results of various keyword searches in Scopus to identify key trends and research gaps related to lunar radiation dosimetry. The analysis revealed a growing body of research focused on radiation protection, the biological effects of ionizing radiation, and simulation models to assess radiation exposure on the Moon. Furthermore, the analysis highlighted an increasing involvement of various countries worldwide in these research areas, with the United States leading in the number of publications. This study provides a global overview of the current state of research in lunar radiation dosimetry, emphasizing areas where further investigation is required to support safe human exploration.

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ABSTRACT The Brazilian legal framework for space operations is examined in this paper to find areas lacking planetary defense and to suggest legislative changes that could integrate Brazil into worldwide projects in this field. Brazilian legislation was investigated using a qualitative methodology based on documentary and comparative research, including the current Law No. 14,946/2024, in contrast to the regulatory frameworks of six major countries that have a planetary defense initiative in place. The study revealed important components such as formal acknowledgment of the threat, assignment of institutional responsibilities, and finance systems. The findings expose that Brazil has major legislative gaps that hinder the efficient development of national planetary defense capabilities, even though it has an established space program and pertinent scientific capability in astronomy. With a rising tendency toward integration between near-Earth object (NEO) monitoring programs and national civil defense systems, the comparative research reveals that all the space powers examined—except Brazil—have particular legal provisions for planetary defense. The study concludes that incorporating planetary defense into the Brazilian legal system would not only be a reaction to a growing issue but also a strategic chance for national scientific and technological advancement as well as for establishing Brazil as a proactive participant in world space governance.

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ABSTRACT Unmanned aerial vehicles (UAVs) rely heavily on the global navigation satellite system (GNSS) for accurate localization. However, GNSS signals are often unavailable or unreliable in contested or cluttered environments. This study presents the optimized pose prediction and cross-view (OPsCV), a robust and adaptable navigation framework that integrates deep inertial odometry with a simulated cross-view geolocalization module through an error-state Kalman filter. The system enables dynamic switching from GNSS-based positioning to a fused solution that combines inertial and vision-based estimates as GNSS signal quality degrades. The framework was evaluated using real UAV flight data under persistent GNSS denial, with results demonstrating reliable pose estimation and improved positioning accuracy compared to the UAV’s internal navigation system. The OPsCV method maintained performance even with sparse cross-view updates, confirming its resilience under conservative operational conditions. These findings highlight the potential of fusing learned inertial measurements with statistical vision-based localization for autonomous aerial navigation in GNSS-denied environments.

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ABSTRACT The sustainable use of lunar resources requires efficient processing of lunar regolith, particularly for advanced manufacturing techniques such as selective laser melting and laser engineered net shaping, which demand particles ≤ 100 μm. This research employs the discrete element method (DEM) to simulate a vibrating screen operating in the Moon’s environment, specifically investigating and providing insights into the effects of vibration parameters and screen inclination on screening efficiency, reaching a maximum efficiency of 76.9%. Additionally, the study explores the feasibility of transporting a vibrating screen from Earth to the Moon, considering its mass and the actual capabilities of the Space Launch System Block 1 Cargo, concluding that the screen can be transported to the Moon. Although the simulated efficiency is over 70%, better results are likely achievable by studying other configurations of motion or different geometries for the screen and deck. This work represents the first DEM-based study of vibrating screens under lunar gravity and provides essential insights for in situ resource utilization strategies.

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ABSTRACT To address the problem of sudden failures during multi-parafoil formation transportation, a new fault formation reconstruction method based on the leader-following algorithm is proposed. First, monitoring of parafoil failures is established using an event-trigger mechanism within a numerical simulation framework. If a parafoil fails, the latest detachment time of a replacement parafoil is calculated based on its glide ratio to determine whether the altitude of the replacement parafoil meets the task reconstruction requirements. If it does, the formation is reconstructed using a switching control law for the replacement parafoil, enabling it to join the formation of the failed parafoil. Then, the leader-following algorithm is applied to reconstruct the formation, allowing the new multi-parafoil system to reorganize and complete the task in an orderly manner, with the replacement parafoil stably reaching the new target point as part of the reconstructed formation. Under this method, high-priority airdrop transportation tasks are ensured to be prioritized in the event of sudden failures during multi-parafoil formation operations. Lyapunov’s theory demonstrates the stability of this method. Simulation results validate the effectiveness of the framework, showing that the algorithm can successfully handle sudden failures of individual parafoils during multi-parafoil formation operations.

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ABSTRACT This paper addresses the challenge of geometric camera characterization, a crucial process in various applications such as computer vision, aerial photogrammetry, remote sensing, and robotics. Traditional calibration methods rely on calibration targets or manually defined geometric structures, which limit automation and adaptability, especially in uncontrolled environments. To overcome these limitations, we propose an innovative approach based on deep learning, capable of estimating the camera’s intrinsic parameters directly from a single image. The developed method integrates the Optuna hyperparameter optimizer, which utilizes Bayesian optimization to enhance model accuracy while reducing computational cost and training time. The application of this approach accelerates the search for optimal configurations for neural networks, ensuring an efficient balance between performance and architectural complexity. Experimental results demonstrate a significant improvement in model accuracy, with mean absolute errors and standard deviations in distortion rates at the hundredth-order magnitude level and focal length determination below 6 mm. Compared to the model without the integrated optimizer, there was an over 95% gain in reducing Mean Squared Error (MSE) and an 82% reduction in the standard deviation. This research significantly contributes to the enhancement of autonomous navigation and image-based positioning systems, providing a scalable and automated alternative to conventional modeling techniques (SDE).

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ABSTRACT This paper presents a robust optimization framework for Satellite Launch Vehicle (SLV) and upper stage trajectory design, integrating uncertainties to enhance flight performance, minimize steering workload, and improve reliability. Identifying a robust optimal trajectory under uncertainty is crucial. The methodology begins with developing a robust trajectory for a two-stage SLV. The upper stage trajectory was then optimized assuming the first stage remained fixed. Three-dimensional equations of motion served as constraints. Uncertainties (aerodynamic coefficients, dry mass, engine thrust) were modeled via mean and standard deviation. Four metaheuristic algorithms—genetic algorithm (GA), particle swarm optimization (PSO), grey wolf optimizer (GWO), and invasive weed optimization (IWO)—were utilized. Monte Carlo simulations with 300 iterations incorporated uncertainties. Results show significant trajectory accuracy improvements. For the upper stage, altitude error decreased by 77%, orbital velocity error by 68%, and flight path angle error by 90%. For the SLV, altitude error improved by 80%, orbital velocity error by 78%, and flight path angle error by 82%. These findings demonstrate the framework’s effectiveness in enhancing trajectory performance under uncertainty.

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ABSTRACT This research analyzes intellectual property (IP) management in Brazilian scientific, technological, and innovation (STI) institutions, focusing on the phenomenon of IP outside universities and public research institutes—also referred to as IP misassignment—and its implications for patent ownership. Adopting a quantitative and descriptive approach, the study employs a case study at a public university. Patentometric analysis revealed that 52% of the inventors’ IP filings were not properly assigned to the institution. The most frequent deviation was the improper use of IP information belonging to the institution for economic exploitation (56 cases), followed by the appropriation of ownership by the inventor (34 cases). These findings highlight the diversion of intellectual capital generated with public resources. To address this systemic challenge, the research proposes a six-step framework designed to support Technological Innovation Centers, which, according to the literature, are related to various areas, such as Health, Biomedicine, Engineering, Physical and Life Sciences, Aerospace, and Defense, in monitoring, quantifying, and proactively mitigating such deviations. Ultimately, the study contributes as an essential diagnostic tool for strategic IP management, strengthening the protection of intellectual capital and ensuring appropriate social and economic returns from academic inventions.

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ABSTRACT A recent economic sector, the space economy, has been the subject of discussions at several international events, including the G20, COPUOS, and the World Economic Forum. The evolution of space activities from the traditional space era to the New Space era influences market shares in the global economy. This study aims to identify trends in space economics studies conducted up to 2023. The study used the Google Scholar database with space economy and valuation size of space economy as keywords. Further bibliometric analysis was conducted using VOSviewer, Publish or Perish, and then artificial intelligence (AI) (ChatGPT). The study aims to identify the current direction in space economy research in terms of its subjects, issues, innovation, and publishing output. In addition to global trend research, a study was carried out on the space economy in Indonesia. However, the amount of research on the space economy in Indonesia, however, is still very limited in terms of case studies, which restricts a comprehensive description of the Indonesian space sector and industry. The research also shows how the space economy, as a sector, contributes to creating income for the economy.

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ABSTRACT The objective of this article is to communicate the results of the study that formed the basis for the development of a method for commercializing technologies, developed by a Technological Innovation Center (TIC) responsible for the Scientific, Technological, and Innovation Institutions (STIs) of the Brazilian Air Force (FAB), brought together in the Aeronautical Innovation System (SINAER). It emphasizes the process of entering into licensing and technology transfer agreements, with an emphasis on those of interest to national defense. Its creation was conducted through Design Science Research (DSR), which is a rigorous process of designing artifacts to solve problems, evaluating what has been designed, and communicating the results obtained. The method proved to be effective in organizing the actions and competencies of each element involved in the negotiation and execution of contracts, fulfilling the objectives of the Ministry of Defense (MD) in transferring the technologies generated by its STIs, making it feasible to prescribe the solution found for the class of problems identified.

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ABSTRACT Polymer composites have been adopted as a structural materials for solid rocket motor envelopes. The mechanical and thermal properties of these composites are strongly influenced by the orientation angle of the fibers. Due to the aerodynamic heating, accurate assessment of the effective heat and mechanical properties is crucial to the success of rocket engine designs. In this work, heat transfer simulation in the wall of a solid rocket engine envelope made of polymeric composite through the finite element method was employed to evaluate the effect of fiber inclination relative to the axis on effective thermal conductivity and effective specific heat, in conjunction with an inverse analysis technique. The results of thermal simulations improved the results and reduced the root mean square error by 12-15% in the mass loss rate, when compared to experimental results for ablation, allowing considering the methodology to be considered validated. The effective modulus of elasticity and the effective Poisson’s ratio are also evaluated, presenting an average deviation of 15.3% compared to experimental results. The results obtained show the dependence of these properties on this geometric parameter, allowing this methodology to be used as a reliable design tool for those systems.

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ABSTRACT Monitoring the reaction between the isocyanate group (NCO) of the curing agent 2,4-toluene diisocyanate and the hydroxyl group (OH) of hydroxyl-terminated polybutadiene is important for the rocket engine loading process, since the reduction of NCO content on the adhesive surface (liner) directly affects adhesion to the propellant. Traditionally, the tack point, which represents the optimal time window for rocket motor loading, is determined based on the operator’s tactile perception. Viscosimetry is employed to monitor adhesive curing and subsequently assess tack; however, as this method evaluates the reaction within the bulk material, adhesion control remains predominantly empirical when chemical reference parameters are preferred. This study proposes a methodology based on infrared spectroscopy (IR) in universal attenuated total reflection mode, evaluating four stoichiometric ratios R(NCO/OH): R = 1.00 and, with excess NCO, R = 1.05, 1.10, and 1.15. The ratio R = 1.05 showed the best performance, with a methodological error of 4%. The main contribution of this work is a fast and precise IR surface analysis that enhances process control during solid rocket motor loading.

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ABSTRACT Machining composites is more complex than metals due to their non-homogeneous, anisotropic nature and abrasive fibers. The machining process of composites can introduce defects, such as drilling-induced delamination, a critical factor in the rejection of drilled composite components in the aerospace industry and others. Among thermoplastic composites, poly(ether imide) (PEI) stands out for high performance, recyclability, and low cost, and is extensively employed in aerospace applications such as interior panels, structural brackets, and electrical housing. This study examines drilling parameters for carbon fiber/PEI composites to minimize delamination. In this study, four carbide tools with different point angles were tested: two with point angles of 118° and 140°, respectively, both coated with titanium nitride (TiN), one with 90° coated with diamond, and a last one with two point angles of 90° and 118°, without coating. Parameters followed manufacturer recommendations with three rotational speeds (4,000, 6,000, 8,000 rpm) and feed rates (0.025, 0.038, 0.050 mm/rev). Delamination was analyzed via high-resolution optical microscopy and ImageJ 1.54. Analysis of variance and Tukey tests identified optimal conditions. Hole entrance damage depended on rotation speed and tool geometry, with higher speeds causing more damage; the 140° point angle caused less than 118°. At the hole exit, tool type was the main factor, with the diamond tool giving the best finish. Optimal parameters were 4,000 rpm with a diamond tool.

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ABSTRACT Mining has caused serious damage to the regional ecological environment. It is important to scientifically evaluate the restoration effect. This study employed a DJI Phantom 4 real-time kinematic quad-rotor unmanned aerial vehicle (UAV) to map a flux limestone mine area. Digital orthophotomaps, a digital elevation model, and a digital surface model were obtained. Vegetation coverage and water and soil loss were monitored. Data analysis found that the vegetation coverage rate in that the area was in steady growth, and the vegetation coverage rate in September 2024 was 72.49%, which was 6.37% higher than that in September 2020 and 3.15% higher than that in September 2022. The water and soil loss modulus decreased continuously, and the monitoring result in September 2020 was 2,045.92 t·km2a. It decreased to 1,221.77 t·km2a in September 2024, which decreased by 40.28% and 26.14%, respectively compared with September 2020 and September 2022. The plants in the region were mainly herbaceous plants and arbors, with rich species and a good community structure. The results verify that the implemented ecological restoration plan has been successful, and it also provides a powerful case for the promotion of UAV mapping technology in mine environmental monitoring and management.

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ABSTRACT The expansion of unmanned aircraft systems (UAS) usage has highlighted the need for robust safety mechanisms to mitigate operational risks in critical scenarios. In this context, it is envisioned that the potential of the critical decision method (CDM), a semi-structured interview technique that utilizes non-routine incidents to capture the decision-making processes employed in these situations and explore how different actions might have influenced the outcome, can be used to elicit knowledge that will contribute to safe UAS operation. However, there is a gap in the literature concerning the proposals and guidance for utilizing CDM in the systems development requirements elicitation process. This study aims to address this gap by applying CDM combined with model-based systems engineering to systematically elicit the safety requirements for UAS in critical operational scenarios. The methodology involves stakeholder interviews, scenario analysis, and requirements elicitation that reflect both operational insights and situational hazards. Sixty-eight safety requirements were identified for the UA and 51 for their ground control stations, providing a comprehensive framework for enhancing safety. The study concludes that CDM is an effective tool for eliciting requirements, offering significant contributions to the early design phases of UAS projects and supporting the development of safer and more resilient systems.

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ABSTRACT The airbase foreign object debris (FOD) management system is designed to deliver a comprehensive, technology-driven solution that improves airport maintenance, operational efficiency, and overall safety. Its primary objective is to address challenges posed by FOD in critical areas such as runways, taxiways, aprons, and other operational zones. The proposed system integrates advanced sensor technologies, data analytics, and automation to enable accurate detection, identification, and timely reporting of debris. Continuous real-time monitoring of the airfield environment allows early identification of potential hazards, significantly reducing risks and operational disruptions caused by FOD incidents. Automation within the system enhances response coordination by ensuring swift and appropriate corrective actions are taken once debris is detected, thereby minimizing safety threats and delays. In addition, the study employs a dual strengths, weaknesses, opportunities, and threats framework, combined with a comparative regulatory analysis of guidelines issued by the Federal Aviation Administration, the European Union Aviation Safety Agency, and the National Civil Aviation Agency. This integrated approach supports informed decision-making for electric vertical takeoff and landing aircraft integration and vertiport deployment within Urban Air Mobility ecosystems.

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ABSTRACT The structural stability of the grids has a significant influence on the work performance of ion thrusters. To obtain the thermal deformation of the grids for a 30 cm diameter ion thruster, the structural properties of the grids are equivalently analyzed by material mechanics, and the equivalent results are verified. The finite element method is used to study the distribution of thermal stress and thermal deformation of the grids, and the simulation results indicate that, after the equivalent treatment of the grids, the equivalent Young’s modulus of the screen grid and the accelerator grid are 20.792 GPa and 89.435 GPa, respectively. When the grids are equivalently treated as a circular plate and the edge is not constrained, the maximum thermal deformation of the grids caused by tensile stress is 0.311 mm, and the maximum thermal stress is about 1.512 × 106 Pa, which occurs in the center of the grids. When the grid is equivalently treated as a circular plate and the edge is constrained, the maximum deflection occurs in the geometric center of the circular plate. Moreover, the maximum deflection of the screen grid is about 1.145 mm, and that of the accelerator grid is about 0.665 mm; the relative distance variation between the screen grid and the accelerator grid is 0.480 mm. The hot gap test is conducted after the thruster has been operated stably for 2 hours without beam extraction. By comparing with the initial gap of the grids, the test results show that the gap variation between the screen grid and the accelerator grid is in the range of 0.502 ~ 0.553 mm. The compare results show that the theoretical results are in good agreement with the experimental results, which also proves the accuracy of the equivalent structural properties of the grids.

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ABSTRACT The Heat Pipes and TUCA Experiment (an acronym for tubo de calor, which means heat pipe in Portuguese) project, conducted by the National Institute for Space Research, focuses on developing and qualifying a fully Brazilian low-pressure heat pipe technology for satellite thermal control. This initiative builds on research begun in 2003, when INPE demonstrated the feasibility of acetone-based heat pipes as an alternative to ammonia systems supplied internationally. The use of acetone in aluminum heat pipes offers key advantages, including lower toxicity and reduced operating pressure. To support data interpretation, a ground-based replica of the TUCA experiment, named RTUCA, was manufactured and tested before launch. The main objective of this work is to investigate whether non-condensable gases (NCGs) have formed inside the aluminum-acetone heat pipe of the TUCA experiment aboard the Amazonia-1 satellite. This assessment considers the effects of long-term exposure to cosmic radiation since the satellite’s launch on February 28, 2021, while the system remains operational in orbit. Additionally, the study compares the thermal behavior of the heat pipe under microgravity conditions with pre-launch ground tests and with results from the RTUCA setup, which intentionally contains a small amount of NCG. These comparisons contribute to a better understanding of heat pipe performance in the potential presence of non-condensable gases.

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ABSTRACT This paper aims to analyze helicopter accidents occurring in meteorological scenarios where flights should have been avoided, identifying patterns that influence pilots’ misjudgments. This work uses two analytical frameworks: the Human Factors Analysis and Classification System (HFACS) and bow tie diagrams, applied to four selected helicopter accident cases. The HFACS model systematically categorizes failures at four hierarchical levels (organizational influences, unsafe supervision, preconditions for unsafe acts, and unsafe acts), whereas bow tie diagrams visually map threats, preventive barriers, the critical top event, and mitigation barriers related to the accidents. The results consistently revealed organizational and self-imposed pressures influencing the decision-making of pilots to proceed under unsafe weather conditions, but these decisions were also shaped by additional factors, such as inadequate training, insufficient operational oversight, fatigue, poor risk perception, spatial disorientation, and misuse of onboard instruments, such as the meteorological radar. The bow tie diagrams highlighted latent conditions, the inadequacy or absence of safety barriers, and the critical short timeframe available for mitigating actions once control was lost. The study concludes that enhancing organizational oversight, structured training, and proper understanding of avionic systems, particularly weather radar capabilities and limitations, are important to preventing similar accidents in the future.

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ABSTRACT This work presents a methodology to produce the thermal models of the Inertial Navigation System (Sistema de Navegação Inercial), being developed along with its host micro-satellite launch vehicle by the Brazilian Air Force (Força Aérea Brasileira). The rationale is built upon (i) knowledge gathering about the modelling and identification subject and the intended use of the thermal models, (ii) selection of the model’s “box color,” (iii) determination of the theoretical and/or the experimental setup, and (iv) definition of the necessary procedures, which comprise steps, rules, and metrics for selecting and validating the models. Given the “intended use” aimed at facilitating component replacement and parameter tuning, the light-gray box approach is selected, where each component is modelled individually and subsequently grouped hierarchically as submodels. The theoretical setup utilizes the MATLAB + SIMSCAPE environment, while the experimental setup relies on the open-source electronics platform named Arduino. Finally, the procedure is defined whereby the models’ parameters are progressively tuned, based on comparisons between simulation data and experimental measurements, following the progressive aggregation of the system components. The results demonstrate a good correlation between both data and measurements across all aggregation phases. Future work includes complex scenarios and rocket launch campaign results.

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ABSTRACT Hypoxia is a critical physiological risk in high-altitude aviation and aerospace environments, where early detection is essential to prevent cognitive impairment and loss of consciousness among aircrew. Hypoxia-inducible factor-1 alpha (HIF-1α) is a molecular biomarker that is rapidly upregulated under low-oxygen conditions. This study aimed to develop and evaluate a rapid, non-invasive lateral flow immunoassay (LFIA) for colorimetric detection of salivary HIF-1α. A total of 24 saliva samples were collected from participants at the Institute of Aviation Medicine and divided into two groups: sea level (control) and simulated altitude exposure at 10,000 feet. Salivary HIF-1α was detected using the developed LFIA sensor, while peripheral oxygen saturation (SpO₂) was concurrently measured using fingertip pulse oximetry to confirm hypoxic status. All participants tested negative for HIF-1α at sea level, whereas positive LFIA results were observed in all participants after altitude exposure, indicating 100% sensitivity under the study conditions. Mean SpO₂ decreased significantly from 98.1% at sea level to 90.8% at 10,000 feet. The LFIA produced rapid, visually interpretable results within minutes. The LFIA demonstrated high sensitivity and specificity for detecting hypoxia-induced HIF-1α in saliva, potentially as a rapid point-of-care tool for hypoxia monitoring in aviation and extreme environments.

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ABSTRACT Low-orbit satellite communication systems are an important element of geographically distributed heterogeneous networks (HetNets) and enable global fixed and personal mobile communications across the entire surface of the Earth. The article is devoted to the study of the average delay of information exchange in “down” communication line between repeater satellite with phased array antenna with discrete beam hopping (DBH) on board and user terminals. A mathematical model as a queuing system (QS) has been developed to calculate the average delay time of information transmission in “down” communication line. Analytical expressions have been obtained that relate the value of the average delay time to the main system parameters: channel bandwidth, number of scanning beams and of time slots in the scan frame, etc. for two beam scanning algorithms: a static and a dynamic one. The dependencies illustrating the advantages of using the technology of discretely scanning beams are given, including estimate of the gain in the presence of several beams. Estimates of the number of beams of phased array antenna depending on the limitations on its size, antenna pattern and the size of the scanning sector are given, and an estimate of the throughput of the communication line is obtained depending on the number of beams.

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ABSTRACT Waves can impair the gliding stability of amphibious aircraft on the water. This study employed numerical modeling to investigate the hydrodynamics of aircraft floats. Hydrodynamic forces were evaluated for different float cross-sections using the volume of fluid (VOF) method. The influence of wave properties on gliding stability was also investigated, along with forces during accelerated taxiing and the role of the acceleration coefficient. By comparing pressure and vortex patterns, the effect mechanism of wave height and wavelength on the stability was clarified. The findings indicate that the stability is highly sensitive to the position of the wave crest impact relative to the center of gravity. An impact near the center of gravity can cause instability with a wave height of 0.5 m and a wavelength of 5 m. Moreover, the accelerated taxiing exerts the most substantial influence on aircraft stability, potentially triggering roll and pitch motions. These findings offer key theoretical support for the design and optimization of amphibious aircraft floats.

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ABSTRACT The purpose of this study was to identify key stages in the evolution of air defense concepts and evaluate effective approaches to neutralizing modern airborne threats, particularly drones. The research involved analyzing open scientific sources, defense agency reports, and systematizing cases of successful counteractions to drones, with a focus on countries like Israel, Turkey, the United States of America, and Ukraine. The study found that countermeasure effectiveness depends on integrating electronic warfare, cyber tools, physical interception, and artificial intelligence (AI)-based detection algorithms. The use of sensor platforms, electromagnetic countermeasures, and software components reduced response times and improved target disabling probability without kinetic effectors. However, existing air defense systems were largely unprepared for swarm attacks from miniature drones, with conventional weapons lacking energy autonomy for prolonged counteraction. The research highlighted the need for multi-layered defense architectures with a cognitive response cycle under 5 seconds and advanced AI integration. Additionally, international cooperation and information exchange were crucial for developing sustainable early warning systems. The study’s findings can inform the modernization of national air defense programs and regulatory frameworks addressing unmanned technology challenges.

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ABSTRACT This study aimed to develop and evaluate a human-interpretable artificial intelligence (AI) model for short-term operational risk forecasting in air traffic control (ATC). To do so, it compared logistic and Poisson regression models with random forest and gradient boosting classifiers using a transparently generated synthetic dataset designed to reflect realistic workload, weather, staffing, and sector complexity conditions. Model performance was assessed through cross-validation, calibration analysis, sensitivity to class imbalance, and decision-curve analysis. Among the tested approaches, gradient boosting achieved the best predictive performance, with an area under the curve of 0.93, and provided the most reliable probability estimates, outperforming the regression-based baseline models. Explainability analysis using Shapley additive explanations showed that the most influential predictors were controller workload, weather severity, sector complexity, and staffing ratio, which is consistent with established human factors theory. Decision-curve analysis also indicated measurable operational benefit at realistic alert thresholds, supporting potential applications in dynamic staffing and flow management. These findings suggest that responsible AI can strengthen safety management systems by providing accurate, transparent, and reproducible risk forecasts while supporting regulatory expectations for documentation, calibration, and interpretability.

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ABSTRACT The development of hypersonic vehicles increasingly relies on deep learning (DL) models; however, their reliability depends on the coverage of training data. When training datasets exhibit uneven coverage of the operational domain, predictions may retain high statistical accuracy while losing physical meaning. This study examines how a deep neural network (DNN) responds to such uneven coverage in predicting thrust for supersonic ramjets (scramjets), whose thrust computation is based on reliable physical models accounting for Mach number and flight altitude. Two datasets generated through computational optimization sampling of operating conditions using these models are considered; the datasets differ in the uniformity of data coverage across operating conditions. Holding the network architecture, loss function, and optimizer fixed, the DNN trained on the larger, non-uniform dataset achieved lower error but exhibited thrust trends inconsistent with the envelope defined by the physical model used in the optimization. In contrast, the DNN trained on the smaller, uniformly covered dataset yielded slightly higher error, but preserved coherent altitude-conditioned thrust trends across the Mach-altitude domain. These results underscore that adequate coverage is a methodological requirement for physically consistent DL models, indicating that reliable artificial intelligence-based tools in aerospace design depend on careful dataset construction rather than architectural complexity.

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ABSTRACT The article is dedicated to parametric studies of the effect of the rotor blade twist θtw and the rotor disc loading P values on rotor aerodynamics in the vortex ring state (VRS) modes. Sixteen rotor configurations with a loading P in the range of 150 to 600 Pa (in hovering), with a blade twist θtw in the range of 8° to -16°, have been considered. The original free wake model of a rotor has been used for a numerical study. For each of the 16 rotors, the vertical (axial) descent modes (angle of attack of a rotor αR = 90°) in the range of descent speeds Vy = 0 to 26 m·s-1 were investigated. For two selected rotors, the steep descent modes (αR = 80° to 20°) were additionally investigated. The dependences of rotor thrust on the velocity of descent for a fixed blade pitch angle θ(Vy) were analyzed. The boundaries of the VRS modes area have been plotted. The obtained results have demonstrated the significant influence of the θtw and P parameters on the rotor aerodynamics and on the VRS area boundaries. The data obtained can be used in preliminary design and in the process of choosing initial parameters of the helicopter main rotor, and are also useful in developing the future concepts of variable-twist rotors.

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ABSTRACT The pyrotechnic composition of magnesium, Teflon, and Viton (MTV) is employed in solid rocket motor initiation systems, flares, and other applications. No studies addressing its quantification or evaluating statistical models have been reported in the consulted and available literature. Infrared spectroscopy enables the quantification of each component of a system in a fast and non-destructive manner. This study presents the application of the universal attenuated total reflection technique to the analysis of five laboratory-prepared samples with different MTV contents, in which the analytical bands of each component were used in calibration curves through different linear regression models. The test sample results demonstrate adequate agreement between the methodologies, with relative errors below 6.5% for the quantification of Viton and Teflon, with the estimation of Teflon being improved by the use of weighted linear regression. For magnesium, both the simple and weighted regression estimates fall outside the 95% confidence interval, indicating the presence of systematic error. The contribution to the state of the art lies in the evaluation of MTV (as-received samples) through infrared reflection techniques, using different statistical treatments, including those specifically designed for spectroscopic data.

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ABSTRACT A six-component force balance was used to obtain the aerodynamic performance of a NACA 23012 half-span wing model at low freestream speeds of 20 m·s-1 to 50 m·s-1. The half-span wing model is equipped with a leading-edge slat and a trailing-edge flap. The impact on aerodynamic performance by the slat and flap configurations of the half-span wing model is studied. Abundant high Reynolds number aerodynamic performance studies have been carried out on various well-known airfoil profiles, but low-speed aerodynamic performance studies are limited. This work will be used as a benchmark study to support researchers working on NACA 23012 airfoils or wings at low speeds.

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ABSTRACT This study investigates thrust enhancement in corona plasma propulsion systems using a hexagonal emitter configuration and a combined alternating-current and direct-current power supply under atmospheric conditions. Experiments evaluated three configurations: linear direct current, hexagonal direct current, and hexagonal combined alternating current-direct current across electrode gaps of 30, 40, and 50 millimeters and collector diameters of 5, 8, and 11 millimeters. Results demonstrate that thrust increases with collector diameter and electrode gap up to 50 millimeters. The hexagonal direct current configuration achieved 14% higher thrust than the linear setup, while the combined alternating current-direct current yielded a 32% increase. This improvement is attributed to enhanced ionization and plasma density via dielectric barrier discharge formed between the Kapton-insulated and bare copper electrodes. Efficiency reached 6.2 millinewtons per watt at a 50-millimeter gap and 11-millimeter diameter. Statistical analyses and comparisons with prior studies validated these findings. Ozone production remained below 0.08 parts per million, ensuring safe operation. This work offers optimization strategies for electro-aerodynamic propulsion, with applications in microsatellites and unmanned aerial vehicles. Future research will focus on testing negative corona polarity.

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ABSTRACT The obstacle avoidance flight of unmanned parafoil formations in complex terrains and under wind disturbances is essential for the success of airdrop missions. This study develops a comprehensive dynamic model of the parafoil and constructs a three-dimensional mountainous simulation environment. An obstacle avoidance algorithm based on the spatial velocity vector method is proposed, which dynamically regulates the parafoil’s motion through traction, avoidance, and guidance velocity vectors, thereby achieving efficient obstacle avoidance in complex wind fields. By incorporating a consensus-based leader-follower formation control strategy, the parafoil formation maintains both geometric configuration and heading stability during obstacle avoidance maneuvers. Simulation results demonstrate that the proposed method effectively enables safe obstacle avoidance and stable formation flight under wind disturbances, confirming the effectiveness of the algorithm.

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ABSTRACT This work presents an experimental study on the effects of surface irregularities, specifically bumps and gaps, on boundarylayer transition. Transition mechanisms are investigated using hot-wire anemometry and a Preston tube. The experiments were conducted in the low acoustic noise and turbulence (LANT) wind tunnel at the Universidade de São Paulo, employing a flat-plate model with a variable insert capable of generating either a bump or a gap. The results show that bumps have a significantly stronger impact on the amplification of Tollmien-Schlichting waves than gaps, with amplification levels approximately four times higher for bumps at |h/δ∗| = 0.64. Furthermore, the critical height required to trigger bypass transition is lower for bumps than for gaps. In particular, bumps promote a rapid upstream shift of the transition location already at h/δ∗ = 1.29, whereas a comparable abrupt advancement toward the irregularity is observed for gaps only at h/δ∗ = −3.22. The data indicate that bypass transition induced by gaps is associated with Rossiter-type instabilities. In contrast, bypass transition over bumps appears to be governed by a distinct mechanism related to the growth of a downstream recirculation bubble, which induces an inflectional boundary-layer profile and gives rise to a high-frequency amplification band.

Resumo em Inglês:

ABSTRACT This work presents the design, simulation, and validation of an embedded guidance, navigation, and control (GNC) system on a simulated onboard platform for the first stage of a microlauncher vehicle. The objective is to evaluate the performance and feasibility of an embedded control architecture throughout powered flight. The control strategy adopted is a proportional-integral-derivative (PID) controller with gain scheduling, employing gains that are tuned by a linear quadratic (LQ) approach to counteract vehicle dynamics changes. The guidance unit supplies reference attitude angles, and the navigation unit estimates vehicle orientation based on inertial measurements in rotation matrices and Euler angles. The validation process involves software-in-the-loop (SIL) and hardware-in-the-loop (HIL) simulations, with the GNC algorithms executed in real time on an embedded hardware platform. Results show excellent pitch stabilization, accurate tracking of the reference trajectory, and actuator commands within operational limits. The simulated vehicle response is well correlated with expected mission profiles. In addition, functional requirements and verification procedures for the GNC system are also formally stated. These findings justify the development of robust embedded avionics systems for microlaunchers and provide an experimentally verified methodological framework to be applied in the future in small satellite launch vehicles.

Resumo em Inglês:

ABSTRACT Over the past decade, nanosatellites have evolved from simple educational platforms into effective tools for scientific research, technology demonstration, and commercial services. This growth resulted in a sharp increase in deployments in Low Earth Orbit (LEO), contributing to its congestion. Very Low Earth Orbits (VLEO), typically below 400 km, are therefore becoming an attractive alternative. Their proximity to Earth offers advantages such as improved sensing performance and reduced communication latency, but also introduces significant challenges due to the strong aerodynamic resistance in the denser atmospheric layers. A particular feature of VLEO is the stronger interaction with Earth’s geomagnetic field compared to LEO, suggesting that passive magnetic attitude control (PMAC) may be effective in this regime. Therefore, this paper presents numerical simulations, based on a methodology developed at Samara University, to assess angular-velocity damping using soft magnetic materials in VLEO. The simulations account for spacecraft-specific parameters, mission requirements, and different possible configurations. The methodology is described in sufficient detail to allow reproduction, providing a practical tool for early mission design.

Resumo em Inglês:

ABSTRACT The formulation of public policies to promote innovation should be supported by empirical evidence, ensuring greater reliability in their design and implementation. The role of the State in supporting an innovation ecosystem has been widely recognized as essential for economic and social development. In this context, the present study examines whether military investments in Brazil are associated with patent production. Using annual data from 2001 to 2019, a dynamic distributed lag specification is estimated to assess whether defense expenditures are related to changes in technological innovation over time. The results indicate a positive association between government defense spending and the number of patents filed, particularly with a 1-year lag. Given the limited sample size (19 annual observations), the findings should be interpreted as exploratory evidence of a lagged relationship. Overall, the results are consistent with a positive temporal association between defense expenditure and patent activity, without implying causal inference.

Resumo em Inglês:

ABSTRACT Inter-regional connectivity is a crucial necessity in various emergencies; however, the limited standard of runways in remote areas poses operational challenges for conventional aircraft. This study aims to investigate the influence of geometric parameters and installation positions of rectangular counter-rotating vortex generators (VGs) on a NACA 4415 airfoil used for short take-off and landing (STOL) amphibious planes. Numerical simulations using the Reynolds-averaged Navier-Stokes k-ω shear stress transport turbulence model were conducted to analyze aerodynamic performance across various angles of attack. The results indicate that VGs effectively delay flow separation and improve the lift-to-drag ratio, particularly at medium to high angles of attack. Geometric parameters such as a height of 30 mm and a length of 4.5 h proved to provide the most rational performance for take-off and landing conditions. However, the installation of VGs also introduces adverse effects in the form of increased parasitic drag at low angles of attack, potentially impacting fuel consumption during the cruise phase. Overall, the proper configuration of VGs significantly enhances the safety and operational efficiency of amphibious aircraft on short runways.