Search Results (162)

This paper presents the results of a low-cost environmental testing campaign performed on commercial off-the-shelf components intended for aerospace applications, specifically a housekeeping system designed for suborbital launchers. These tests encompass a broader range of thermal and mechanical testing procedures than is typically reported in the literature, providing a more comprehensive assessment of the system’s robustness. The housekeeping system is subjected to sine-equivalent dynamic loads representative of launch environments expected by vehicles such as Ariane 6, VEGA, and Falcon 9 using a shaker. In addition, thermal vacuum testing is conducted to evaluate system performance under temperature and pressure conditions representative of high-altitude flight. Following each test, the system’s functionality is assessed by comparing its performance against baseline laboratory conditions using telemetry data acquired by the system; most importantly, a critical failure on telemetry data acquisition is verified, which determines the survivability of the system. The successful completion of these environmental tests demonstrates the survivability of the housekeeping system, validating its reliability and suitability for operation in suborbital launcher missions. Full article

This study develops workflows derived from the non-contact survey of small anthropic markers along the northern stretch of Pompeii’s urban walls. For valid reasons currently being verified, these indentations have been attributed to the impact of darts fired by Sulla’s artillery in 89 BC. Consistent with published findings, the morphometric data obtained from the casts of the impressions generated by the metal tips were used to obtain measurement modules suitable for measuring the reconstruction of SCORpiò-NIDI. To achieve this result, calibration formulas handed down directly from the Greeks and Romans were used. The method adopted reverses the usual sequence, starting from the effects and arriving at the causes. According to the principles handed down by ancient treatise writers, typical 2D-3D graphic modeling investigations guided the commensuration of parts. A family of dart-launcher prototypes was created based on the measurement module, to be tested and mechanically analyzed through reverse engineering processes. The creation of virtual models was not based on the dimensions of the findings, but rather on parameters that study the reaction of stone blocks to the impact of blunt objects. The results aim to raise operational criticism, contributing to the debate on “certified” typological families of reconstructions based on objective data and verifiable calculations. Full article

Rockets were launched from a freely ascending balloon, and the attitude dynamics of the rockoon system were investigated. Compared with ground-based or aircraft-based launches, rockoons offer reduced aerodynamic drag and pressure losses, leading to higher maximum altitudes of sub-orbital trajectory and improved launch capacity to earth orbits. To ensure trajectory accuracy and flight safety, an azimuth control system based on a control moment gyroscope (CMG) was implemented. The launcher, suspended beneath a helium balloon, was equipped with a CMG device for active azimuth control. Three model rocket launches were conducted, and attitude data were obtained using multiple accelerometers installed on the rocket and launcher. The results confirmed that azimuth control remained effective during free ascent, with the azimuth error at ignition within 7° of the target in all three launches. Oscillatory motion was observed in roll and yaw angles. It was identified as rotation about the launcher’s principal inertia axis, indicating no significant impact on the rocket’s flight trajectory. Additionally, pitch-up behavior during launch due to rail friction was observed, consistent with previous studies. Frequency analysis showed that a double-pendulum model reproduced the measured first-mode frequency within approximately 2%, while the measured second-mode frequencies were higher than the predictions, indicating an increase in the effective pendulum length due to the relaxed constraint of the balloon suspension. Under free-flight conditions, the first mode was no longer observed within the measurable frequency band, consistent with the removal of the ground constraint. These findings provide an experimental characterization of the attitude dynamics of rockoon launches with active azimuth control. Full article

This study investigated the integration of 3D-printed tensegrity launch tubes and compliant mechanism components into small-scale industrial line launcher systems. A multi-variable experimental design (n = 108 replicate shots) evaluated a seven-segment PLA tensegrity tube, the potential for a monolithic compliant launcher, and a pneumatic benchmark across various projectile types, tube configurations, and muzzle rifling geometries. The system exhibited a severe 57.4% launch failure rate, with failures concentrated in extended tube configurations and Rigid or Compliant muzzle attachments. To isolate the dominant operational drivers across the dataset, a composite velocity score was analyzed. Non-parametric variance testing identified tube configuration as the primary factor influencing velocity (Kruskal–Wallis H = 26.73, p < 0.001), followed by muzzle geometry (H = 10.20, p = 0.017). Post-test disassembly identified three distinct failure modes, primarily driven by bore clearance rather than the vibrational compliance of the tensegrity architecture. A Failure Mode and Effects Analysis (FMEA) quantified these risks, identifying tensegrity tube bore constriction as the primary threat to system reliability (Criticality = 336). Process capability analysis against Stage 1 prototyping gate criteria confirmed the system is not yet process-capable. Furthermore, a Total Cost of Ownership (TCO) analysis yielded an estimated US $8.07–11.22 per successful launch, challenging the economic scalability of low-cost additive manufacturing materials. This study establishes quantitative benchmarking and a reliability-centered Design for Additive Manufacturing (DfAM) framework required before scaling toward maritime, emergency, or aerospace applications. Full article

As a paradigm-shifting hypervelocity propulsion technology, electromagnetic rail launch (EMRL) is fundamentally constrained by armature/rail (A/R) interface degradation, which directly erodes its service longevity and operational reliability. Small-caliber circular bore electromagnetic launchers (SCCB-EMRL) offer superior structural integration and ballistic stability over traditional rectangular bores. Their inherently lower self-centering capability imposes strict requirements on interfacial contact stability. This study investigates the physicochemical evolution of the A/R interface at extreme loading. Consecutive repetitive launch experiments were conducted, and samples were prepared by typical areas of rail according to the current curve. Characterization was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. Results revealed a bimodal non-uniform thickness distribution of the deposition layer along the launch direction. The maximum deposition thickness reached 60.6 μm within the acceleration-startup zone. The deposited material comprises transferred Al, oxidized phases (Al₂O₃), Al-Cu intermetallic, and a mixed carbonaceous system containing amorphous and graphitized carbon. Initial launches triggered rapid material accumulation and increased start-up times, after which the interface reached a dynamic equilibrium. This work reveals the evolution patterns of elemental composition and thickness distribution of the deposition layer at the armature/rail interface in small-caliber circular-bore electromagnetic launching and provides experimental reference for the design of anti-deposition coatings to extend the service lifespan of SCCB-EMRL systems. Full article

Hybrid rocket motors are an attractive option for the upper-stages of low-cost small launchers, but are susceptible to variability in performance both in time and between firings. Moreover, key contributors to hybrid motors’ performance such as oxidizer-to-fuel ratio ($O/F$) are difficult to estimate, and by extension, to control. Four approaches were evaluated for the estimation and control of $O/F$ under system uncertainty, including through on-line estimation by an Unscented Kalman Filter (UKF). A Monte Carlo analysis was conducted of a simulated hybrid kick motor, where key sources of system uncertainty such as the characteristic velocity efficiency (${\eta }_{c^{*}}$), fuel regression coefficients, and oxidizer flow characteristics were allowed to be variable. Feedback control of $O/F$ informed by the UKF obtained 6.8% smaller control error than the best alternative approach. Yet the Monte Carlo analysis showed that among uncertainty sources considered, ${\eta }_{c^{*}}$ was the primary driver of performance variability, while $O/F$ regulation had a small influence. This was because the total and specific impulses were relatively insensitive to $O/F$ for the considered motor configuration and ranges of $O/F$ observed during the simulated burns—highlighting the importance of system uncertainty quantification when formulating performance-regulating interventions. Further, the proposed UKF observer provided data-informed estimates of combustion efficiency and propellant residuals in time, which are valuable for the planning and execution of accurate orbital insertions in a kick motor susceptible to performance uncertainty. The developed uncertainty quantification and control modeling framework can be used also during the design and assessment of other control interventions under system uncertainty. Full article

Experimentation in science education faces significant access limitations, both in face-to-face and distance learning settings; in light of this situation, remote laboratories are emerging as a strategic solution. The aim of this study is to present the design and development of an ultra-concurrent remote laboratory focused on the study of projectile motion. Using the Design-Based Research methodology, the resource has been structured around an iterative five-phase approach: design, data capture, development, test and improvement, and integration. The data acquisition system was developed using a hardware setup comprising a projectile launcher, photo gates, a digital interface and a time sensor, implemented and managed via the LabsLand platform. The laboratory integrates semi-parabolic and full-parabolic configurations via an interactive interface that guides the user from connecting components to the multimedia observation of real experimental data. The results of the experimental validation confirm the system’s viability, as the data obtained compare with ideal kinematic equations and reflect, as expected, the behaviour and physical limitations of the real-world environment. This laboratory offers a potential pedagogical advantage, reporting percentage errors around $3$–$11\%$, as it exposes students to experimental uncertainty whilst simultaneously ensuring simultaneous and free access for multiple users in science education. Full article

Additive layer manufacturing is changing the industrial landscape worldwide, particularly in high-end technology sectors, including aerospace applications. In mechanical engineering, and particularly in the aerospace industry, it is essential for quality certification that components are produced using qualified and robust manufacturing processes that guarantee high product repeatability. Unfortunately, nowadays, too few standards are available for the qualification of products manufactured by additive technologies for the aerospace sector. The aim of this work is to qualify a metallic space component, manufactured by additive technology, according to ESA ECSS standards: in particular, the qualification of a non-conventional configuration of the interfacing flanges used to connect two adjacent space launcher’s stages, manufactured by Electron Beam-Powder Bed Fusion (EB-PBF) additive technology, is presented in the present work. Full article

In view of the practical engineering demand and performance optimization of compressed air-driven fire-extinguishing projectile launchers, a two-dimensional axisymmetric compressible flow numerical model is established based on ANSYS Fluent 2023. Numerical verification is conducted by comparing with classical zero-dimensional theoretical results and reference data from the published literature to guarantee simulation accuracy. Combined with the internal ballistic motion characteristics, the present study systematically investigates the effects of initial pressure, flow passage structure, loading position and projectile mass on launch dynamic behavior and the energy utilization mechanism. The results reveal that the initial high-pressure chamber pressure dominates the total energy output of the system. Appropriately increasing the valve gap and nozzle diameter can improve flow characteristics and energy transfer efficiency. Adjusting the loading position and barrel length effectively balances the internal ballistic response, while larger projectile mass brings higher inertial resistance and obvious efficiency attenuation. This work clarifies the quantitative influence of key structural and operating parameters, and provides theoretical support and engineering reference for the design, parameter matching and performance improvement of similar fire-extinguishing launching equipment. Full article

This work presents a service-oriented launcher for ESERO Greece’s CanSat 2025, delivering four reusable rockets that reach 1000 m and perform clean, near-apogee payload deployment with safe recovery. A requirements-driven process combined with systems engineering principals that utilized simulation based conceptual design, trajectory analyses and subsystem ground testing managing to deliver a modular, cost-effective and reusable system. All vehicles were used offering 12 flawless flights, fulfilling their missions. Overall, results validate the architecture and methodology under competition constraints, with vehicles ready for reuse and clear avenues for simplification offering directions for further future improvements. Full article

Digitalizing essential services opens up a new risk of exposing critical infrastructure to botnet infections. In a grid topology network, the neighbor-to-neighbor paths can be used by the malicious botnet to spread the infection. Previous white-hat worm launchers used heuristics and supervised learning to exterminate botnets, which demand specific conditions or a suitable dataset to be effective. Although reinforcement learning addressed these issues, it requires a longer time to train. This article proposes a framework to shorten training and improve the effectiveness of reinforcement learning. The framework applies four key principles: (1) surveying the network status with multi-tensor input, (2) removing irrelevant actions via a novel Chebyshev-based masking strategy, (3) reinforcing key actions with rewards, and (4) optimizing rewards for winning. Four reinforcement learning algorithms are implemented to evaluate the framework, which are vanilla policy gradient, deep Q-network, proximal policy optimization, and MuZero in a stylized grid topology network simulation. An ablation study indicates that the masking used in identify accounts for the majority of the improvement, whereas multi-channel in Survey alone can reduce performance without complementary masking, rewards, and optimization. With the mean winning rate improved by 49.129% and mean win efficiency improved by 118.8031% against our previous work, the framework effectiveness is confirmed in stylized simulations. Full article

Satellite containerization is a key factor in the expansion of the aerospace sector. In addition, the container provides a highly simplified launch interface, reducing the launch provider’s integration costs. In this scenario, DiskSats have been proposed as a new standard for a high-power-to-mass-ratio platform that can be easily stacked within a launcher fairing. However, their behavior in Very Low Earth Orbits remains underexplored. The primary research objective of this study is to characterize the macroscopic aerothermodynamic behavior and aerodynamic footprint of a DiskSat platform operating in Very Low Earth Orbit (VLEO) at altitudes of 100, 150, and 200 km. At such altitudes, the continuum hypothesis is no longer valid, and a particle-based method should be used for computations in the rarefied-flow regime. In this way, the Direct Simulation Monte Carlo (DSMC) method was employed to analyze the flowfield structure around a DiskSat at different altitudes. In the present investigation, the Knudsen number associated with each altitude ranged from 0.14 to 240. According to the computational results, a compressed shock layer with higher temperature was observed over the DiskSat at an altitude of 100 km. However, the 200 km case shows a highly diffuse interaction that extends significantly upstream due to the larger mean free path. In addition, a thermally frozen, near-vacuum wake region is observed across all altitudes. These findings characterize the aerodynamic footprint of planar geometries, establishing a critical baseline for future analyses of orbital lifetime and stability in the transition and free-molecular regimes. Full article

The topic of reusability in the launch vehicle sector is of current worldwide interest, as a shift from expendable to partially reusable configurations can be observed. Based on the work realized in a nationally funded Nucleu project, INCAS has developed a multidisciplinary optimization environment (MDO algorithm) capable of generating preliminary launcher concepts that also take into account the recovery process needed to reuse key major assemblies, such as the lower stage. The current paper analyzes a set of five key missions of interest (with different launch locations) and their influence on the preliminary definition of a family of partially reusable microlaunchers capable of inserting the same payload (100 kg) into different inclination, low Earth orbits (ranging from almost equatorial to Sun-synchronous orbits). The proposed microlauncher concepts are based on a two-stage constant-diameter architecture, where the first stage is recovered via a downrange, autonomous vertical landing mission, while the upper stage is expendable. The main scope of this paper is to quantify the impact of different key mission requirements on the characteristics of the reusable microlauncher that minimize its lift-off mass. This approach also correlates to the definition of reusable launch vehicle concepts that have reduced the associated costs of development, production, and operation. Full article

The high-speed motion of a vehicle underwater induces cavitation, and the resulting cavity alters the surface pressure distribution and flow field characteristics. This study employs a numerical approach combining the $\mathrm{k}-\omega$ SST (Shear Stress Transport) turbulence model, the VOF (Volume of Fluid) multiphase flow model, the Schnerr–Sauer cavitation model, and the overlapping mesh technique. The numerical method is validated through the good agreement between simulation results and experimental data for both cavity shape and vehicle trajectory, with a maximum relative error of 6.1% in vertical displacement. The results indicate that during the launch-tube exit phase, with $\sigma =0.235$ and $\mathrm{Fr}=47.9$, the vehicle acceleration causes the pressure at its shoulder to drop below the saturated vapor pressure, initiating cavitation. Under transverse flow (intensity U = 0.016–0.05), the cavity becomes asymmetric. Specifically, the axial length and radial thickness on the back side are significantly larger than those on the face side, and this asymmetry intensifies with increasing transverse flow intensity. Furthermore, after exiting the launcher, the vehicle’s trajectory and attitude deflect towards the back side and the deflection amplitude increases, with horizontal displacement and attitude angle variation positively correlated with transverse flow intensity. Full article

Reusable launch vehicles are a key category of next-gen European launchers, as multiple companies are in advanced stages of study and are shifting towards the development of first demonstrators. A worldwide tendency to reduce the costs associated with satellite insertion into low Earth orbits can be observed, together with the existence of a niche in the future European launcher family for reusable small launch vehicles, known as microlaunchers. Multiple recovery methods exist for space launch vehicles; in this study, a return to launch site (RTLS) vertical-landing approach is being prioritized for the recovery of the first stage of a two-stage LOX/methane microlauncher. In 2023, INCAS, with support from the Romanian Nucleu Program, initiated a large study to address the prospect of developing a partially reusable microlauncher. A multidisciplinary optimization (MDO) environment has been developed, which is used in this paper to assess the implications of stage recovery versus the landing location (return to launch site versus downrange recovery) and state whether an RTLS can be feasible for small launchers. The paper will also present some key results from previous studies, such that a clear solution trade-off can be made, together with the quantitative assessment of how different vertical-landing techniques affect the microlauncher specifications. Full article