Hasil untuk "Explosives and pyrotechnics"

Albert G. Nigmatov, Kyrill Yu. Suponitsky, Valery P. Sinditskii et al.

The synthesis of energetic compounds of the gem-dinitrocarbocycle family, furazan and furoxan fused to dinitrocyclohexane, is reported. The construction of the gem-dinitro moiety was achieved by nitration of the hydroxyimine group by using both fuming and dilute nitric acid. These hybrid materials were characterized with respect to their spectral and energetic materials properties. The structural features of furazan 5 and furoxan 6 were revealed using X-ray crystallography. Energetic compound 5 was found to exhibit melt-castable properties, with a melting point of 78 °C and an onset decomposition temperature of 198 °C. It was insensitive to impact, with a calculated detonation pressure ca. 21% higher than the benchmark melt-castable explosive TNT.

Xuemei ZHANG, Xingbo XIE, Mingshou ZHONG et al.

To select the shaped charge structure suitable for large-distance non-contact penetration damage in water, three typical shaped-charge structures, explosively formed projectile (EFP), jetting projectile charge (JPC), and shaped charge jet (SCJ), were selected. The velocity tests of different penetrators before entering water, before hitting the target, and after penetrating the target were carried out, and the penetration tests of double-layer spaced targets in water were conducted. Firstly, a comparative test of penetration of three types of shaped charges in the air was carried out to verify the rationality of the structure of shaped charges. The air explosion height of 35 cm was selected to meet the penetration requirements of the three shaped charges. At the same time, the velocity of the shaped charges before penetrating water was measured, which provides the basis for the underwater penetration test. Secondly, the penetration test of three types of shaped charges on an underwater double-layer spaced target was carried out when the air height was 35 cm, and the length of the water medium in front of the target was 20, 45, and 100 cm. The reflected pressures were measured by the wall pressure sensor and PVDF sensor. The velocities of the penetrator at the time of water entry, before the target, and after the target were measured by double-layer on-off net targets.The damage performance of three shaped charge structures on the double-layer spaced target plate was respectively obtained when the water medium in front of the target was at short range, medium range and long range.Based on the projectile-target structure used in the experiment, a two-dimensional finite element model of shaped charge penetrating a double-layer spaced target in water was established using ANSYS/LS-DYNA finite element software. The measured velocity values of the shaped charge penetrator before entering the water, before hitting the target, and after passing through the target were compared with the numerical simulation results to verify the accuracy of the model. The error rate is about 3%. Based on the verified finite element model, the time series characteristics of the underwater damage element of the shaped charge, the peak characteristics of the forward shock wave in the water, the variation law of the penetration velocity in the water, and the penetration performance of the shaped charge against the double-layer spaced target in the water were studied. The results show that the forward shock wave reaches the target plate before the penetrator. As the length of the water medium increases, the peak pressure of the forward shock wave at the front target plate decreases linearly, and the peak pressure of the forward shock wave at the rear target plate decreases nonlinearly. The velocities of EFP, JPC, and SCJ decrease nonlinearly with the increase of water medium, and the velocity in front of the SCJ target is about twice that of JPC. When the length of the water medium in front of the target is not more than 25 cm, the maximum perforation diameter formed by EFP on the front target plate reaches 5 cm, which is 1.3 times the perforation diameter of JPC and 3 times the perforation diameter of SCJ. When the length of the water medium in front of the target is not more than 100 cm, JPC and SCJ have better penetration effect on the double-layer spacer target, and the penetration performance of JPC is better than that of SCJ.

Slimane Bekhouche, Amir Abdelaziz, Ahmed Fouzi Tarchoun et al.

This study focuses on analyzing the degradation, ignition, and combustion behavior of a silicon (Si)-based pyrotechnic delay mixture. A comparative analysis is conducted between a fresh sample and one exposed to accelerated aging conditions at a constant temperature of 65 °C and 85% relative humidity for 120 days. The findings indicate that the average burning rate decreases by factors of 1.3 and 2.2 for the thermally aged and moisture-exposed samples, respectively. Furthermore, in comparison to the unaged composition, the total energy output is reduced by 38.5% and 66% for the thermally aged and moisture-affected samples, respectively. TG analysis shows that humidity and thermal aging act as catalysts, accelerating the decomposition reactions and reducing the decomposition onset temperature by approximately 1–4 °C. TGA/DTG analysis reveals a multiple-stage reaction process, including binder decomposition, oxidizer pre-decomposition, and combustion of the pyrotechnic composition. Thermal analysis, incorporating the peak deconvolution technique, identified sub-reactions occurring within the primary exothermic process, including #1 (Si and Pb3O4), and #2 (Si, Pb3O4, and BaCrO4). The activation energy (Ea) of the second combustion stage displays a slightly higher value for the aged samples compared to the fresh composition.

Huming LIAO, Yanhong YANG, Zhirong GUO et al.

With the development of modern weapon systems, the requirements for the survivability of ammunition in various complex environments have been continuously increasing. During the processes of storage, flight, and combat, ammunition may be subjected to extreme impact loads such as high-speed impacts, shock waves, bullet and fragment impacts. The external impacts can induce plastic deformation and fracture of the ammunition casing, and even detonate the internal explosives. These responses involve complex phenomena including impact loading, thermo-mechanical coupling of materials, chemical reactions of explosives, and blast effects, representing a typical dynamic response problem of reactive materials under extreme thermo-mechanical coupling conditions. Accurately predicting the responses of ammunition under impact loading is critical for its design optimization and safety assessment. Based on the Hot Optimal Transportation Meshfree (HOTM) method, a meshfree numerical approach was proposed to accurately predict the ammunition responses under different impact loadings. Meanwhile, a thermo-mechanical-chemical coupling constitutive model of explosives was established, which took the effects of temperature and pressure on the explosive’s chemical reaction and detonation into account. The Arrhenius thermal-chemical reaction coupling model for explosive initiation and the Lee-Tarver three-term pressure ignition model induced by local high pressure were integrated to accurately simulate the different initiation mechanisms of explosives under varying impact velocities, thereby predict complex physical phenomena during the impact loading of ammunition. These phenomena include high-speed contact, large plastic deformation of the metal casing, material fracture, heat conduction, explosive initiation, and the expansion work performed by chemical reaction products. Taking the numerical simulations of two typical impact scenarios—bullet impact on ammunition at 850 m/s and fragment impact at 1850 m/s—as examples, the influence of impact velocity on the initiation mechanisms of explosives and the overall response of ammunition was analyzed, with comparisons made against relevant experimental results. The proposed approach and findings provide reliable technical support for the optimization of impact-resistant design and safety assessment of ammunition.

Yaoyao Linghu, Chaoyang Zhang

A clear structure-sensitivity relationship in energetic molecules is beneficial for designing energetic materials. At the molecular level, sensitivity is closely related to the bond dissociation energy (BDE) of trigger linkages like C/N/O-NO2 in the widely used nitro compounds. Herein, the BDE of C-NO2 in a series of designed five- and six-membered N-heteroaromatic derivatives, including pyrrole, pyrazole, imidazole, triazole, tetrazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, tetrazine, and pentazine, are investigated to quantify the impact of substituent groups and N atoms on aromatic rings on it. We find that introducing pyridine-type N atoms decreases the BDE and increasing their number further reduces it. Additionally, increasing vicinal pyridine-type N atoms and C-NO2 also lowers the BDE. Conspicuously, the intramolecular hydrogen bonding between vicinal C-NO2 and C-NH2 facilitates high BDE.

Yanlei Qu, Lei Niu, Jianlin Xu et al.

The development of flame-retardant composites with outstanding mechanical features is critical for enhancing the safety and performance of propellant liners in solid rocket motors. This study investigates the mechanical properties of polybutylene terephthalate (PBT) composites reinforced with surface-modified recycled glass fiber (RGF). The surface modification of RGF was done with the cationic surfactant cetyltrimethylammonium bromide (CTAB) and the silane coupling agent γ-ammino-propyltriethoxysilane (KH550) as the modifying agents. In this experiment, the modified RGF/PBT composites were prepared by injection moulding method. The chemical structure of modified RGF was investigated by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The mechanical properties of RGF/PBT composites were investigated by tensile test, impact test and bending test. The results showed that the experiment successfully introduced CTAB and KH550 to the surface of RGF, and prepared surface-modified RGF, which improved the interfacial bonding strength between RGF and PBT matrix, resulting in the improvement of the mechanical properties of the modified RGF/PBT composites, and the RGF composites obtained by the KH550 modification had better properties. The improved impact resistance and mechanical stability of the modified RGF-PBT composites suggest their potential use as insulation materials in high-energy systems, such as protective casings for energetic formulations in pyrotechnics and propellant applications.

Hani Boukeciat, Ahmed Fouzi Tarchoun, Djalal Trache et al.

The present study aims to elucidate the decomposition mechanism and gas evolution characteristics of a promising energy-rich carbamated microcrystalline cellulose nitrate (M3CN). The molecular structure and morphological characteristics of starting microcrystalline cellulose carbamate (MCCC) and its nitrated derivative were examined using FTIR and SEM techniques. Thermal analysis using TGA and DSC revealed distinct decomposition behaviors for MCCC and M3CN. MCCC exhibited endothermic decomposition linked to the degradation of the cellulosic structure. In contrast, an exothermic decomposition event was observed for M3CN, attributed to the cleavage of energetic groups within the nitrated cellulosic chains. Furthermore, the hyphenated TG-FTIR analysis confirmed that the primary gaseous products emitted during the pyrolysis of M3CN included NO, N2O, NO2, CO2, H2O, CH4, HCHO, HCN, and CHNO. The findings of this study enhance our understanding of the pyrolysis mechanism in cellulose-based energetic materials, providing a significant reference for forthcoming research and explorations in this field.

James C. Thomas, Gavin D. Lukasik, Felix A. Rodriguez et al.

Metal fuels, such as aluminum (Al) and iron (Fe), can be added to composite solid propellants to improve their performance, such as specific impulse, density, and burning rate. In comparison to aluminum, iron can theoretically provide improved density specific impulse and higher flame temperatures; reduce condensed combustion product (CCP) concentration and the associated two-phase flow losses; and eliminate hydrochloric acid (HCl) in the exhaust products. A fundamental and quantitative understanding of metal particle aggregation and agglomeration processes in solid propellants is required to understand the underlying combustion mechanisms in these systems. In the current study, composite strand and laminate AP/HTPB/AP propellant samples loaded with Fe microparticles (∼45 μm in diameter) were burned at elevated pressures in an optically accessible strand bomb. Combustion processes were monitored with transient pressure diagnostics and a high-speed camera fitted with a high-magnification lens system (3.83 μm/pixel resolution) for the laminate propellant experiments. An automated image processing algorithm was developed to measure burning rates and ejected particle/agglomerate sizes and velocities. Time-resolved statistical distributions of both particle size and velocity are presented at elevated pressure for multiple laminate propellant experiments with a high degree of repeatability and low measurement error estimated as < ±5% and < ±1.5% for particle size and velocity, respectively. The incorporation of iron microparticles into the composite strand propellants yielded over a 20% increase in the global burning rate over the range of pressures evaluated (3.45–13.8 MPa). Similarly, the addition of iron to the fuel lamina in laminate propellant samples led to an approximately 30% increase in the global burning rate at the evaluated pressure (3.45 MPa). Additive particles were observed to eject near the oxidizer/fuel interface, or to melt, aggregate, coalesce, and agglomerate on the fuel lamina surface prior to ejection. Particle velocities are controlled by a balance of gravitational forces, drag forces imparted by expanding combustion product gases, and particle inertia. The observed combustion enhancements are attributed to the combined effects of catalytic mechanisms, increased radiation heat transfer, and local energy release from reacting iron particles. In addition, discussions on the image processing methods developed in the current study, corresponding potential sources of error, and prospective areas of improvement are provided. The experimental approach developed enables high-speed and high-magnification visualization of propellant combustion at high pressures and can be utilized to better understand the fundamental combustion behavior of energetic systems.

A. Ingenito, S.K. Palateerdham, M. Panzanaro

Access to space for small private companies requires to improve the ability to bring low-cost satellites into orbit. CubeSats offer a unique opportunity to meet these needs thanks to their reduced production times, the low manufacturing costs and ease of use. In order to be able to communicate with each other, exchange information and interact, it is necessary to place CubeSats in formation: in this context, miniature propulsion technologies, including chemical and electric propulsion, play a critical role in achieving mission requirements and maintaining satellites position. In this article, the feasibility of solid propellant micro rockets, fully integrated in an opposing array of printed thrust chambers is examined: each rocket can be fired together with the others or separately to modulate thrust. Theoretical and experimental results show that the microthruster, made of nylon and carbon fiber, have good mechanical and thermal resistance and simultaneously good performance is achieved. In particular, a microthruster with a diameter of 4 mm and a length of 6 mm, with 55 g of black powder propellant, achieves a thrust of about 3.5 N for about 7 ms.

Chengbo Ru, Lihong Chen, Hongguo Zhang et al.

Abstract Understanding the properties of explosives is the basis for investigating and analyzing explosion cases. To date, due to the strict legal control of standard explosives and initiators, homemade pyrotechnics composed of oxidizers and fuels have become popular explosive sources of improvised explosive devices (IEDs) threatening greatly social stability and personal safety. The reactivity of pyrotechnics strongly depends on their intrinsic characteristics and operating conditions, which determine the efficiencies of heat and mass transfer between the reaction zone and the unreacted zone. Herein, the tests of thermodynamics, pressurization characteristics, and combustion propagation behaviors are conducted to explore the effects of oxidizer species, particle size, and loading density on the reactivity of homemade binary aluminum-based pyrotechnics. The results show that the pyrotechnics with potassium chlorate (KClO3) have the strongest reactivity with the highest pressurization rate (dp/dt) and the shortest combustion duration. Compared with their counterparts based on aluminum microparticles(mAl), pyrotechnics consisting of Al nanoparticles (nAl) possess superior reactivity as expected, which results from the relatively short heat and mass transfer distances. The nAl-based pyrotechnics have a low reaction exothermic peak temperature, great heat release, great aluminothermic reaction completeness, and high produced peak pressure with several orders of magnitude higher pressurization rate. Increasing the loading density of the pyrotechnics over a certain value can change the dominant mode of heat transfer from convective to conduction, sharply decreasing the pressurization characteristics and combustion front propagation velocities (v p ). The results of theoretical calculations using the NASA-CEA codes show that loading density can alter the reaction process of the pyrotechnics, leading to a decrease in the predicted pressure per unit mass for Al/KNO3 or Al/AP, and an increase for Al/KClO3. For nAl/potassium nitrate (KNO3), the density is between 1.0 and 1.25 g cm−3, across which dp/dt decreases by one order of magnitude from 0.148 to 0.014 MPa ms−1. In addition, v p decreases by three orders of magnitude from 0.040 to 0.078 m s−1. Distinct pressurization behaviors of nAl/AP are observed at a density of 1.5 g cm−3, while the variation in nAl/KClO3 reactivity fluctuates. These results are beneficial for the damage assessment of scenes caused by an explosion and for inversely calculating charge parameters.

Shitai Guo, Jing Huang, Wen Qian et al.

Motivated by the excellent detonation performance of octanitrocubane, prismane is another potential backbone with high strain energy in energetic molecule design. In this work, we aim to screen out candidates of highly energetic molecules from the space of prismane derivatives. The high-throughput computation (HTC) is performed based on 200 molecules derived from the molecule space of 1503 prismane derivatives with four substituents. Based on the calculated results, the machine learning (ML) models of density, detonation velocity, detonation pressure, heat of formation and detonation heat are established, and thereby the performances of the remaining 1303 samples are predicted. It is found that the –NHNO2 group increases density, while both –NO2 and –C(NO2)3 groups promote detonation performances. Based on the detonation velocity and bond dissociation energy as criteria representing energy and molecular stability, four molecules were screened out with good detonation performance and acceptable thermal stability. This work demonstrates the efficiency of HTC and ML combined strategy for screening high-quality energetic molecules.

Hongyang Chen, Yaofeng Mao, Jie Chen et al.

Microscale energetic materials have garnered considerable attention because they can be integrated in microelectromechanical systems for several potential applications. Hexanitrostilbene (HNS) has been widely utilized in ignition and initiation devices owing to its excellent thermal and shock stability and high sensitivity to short pulse shock waves. To meet the energy release requirements of micro-detonation devices, HNS sticks were prepared using direct ink writing and their reaction and flame propagation properties were studied. HNS particles sized 17.5 µm to 5 µm and ∼500 nm was prepared. Then, the viscosity of HNS-based inks prepared via acoustic resonance technology decreased when the particle size decreased or when the HNS content reduced from 97 wt.%, 95 wt.%, and 92 wt.%, to 90 wt.%. Additionally, the HNS-based inks with different binders exhibited different viscosity. The effect of the inner diameter of needle (0.4 mm, 0.6 mm, and 0.9 mm), printing rate (13 mm/s, 15 mm/s, 17 mm/s, 19 mm/s), and pressure (0.05 MPa, 0.1 MPa, 0.15 MPa, 0.2 MPa) on the width of HNS sticks was also elucidated. HNS-based sticks with a diameter of 0.9 mm underwent self-sustaining combustion reactions, and the burning rate increased from 5.1 mm/s to 6.8 mm/s as the particle size decreased from 17.5 µm to 500 nm. Overall, this work provides an effective approach to prepare microscale HNS for integration into micro-energetic devices.

Simon M.J. Endraß, Thomas M. Klapötke, Jasmin T. Lechner et al.

1- and 2-Propargyl-tetrazole (1- and 2-PryTz) were synthesized by reaction of propargyl bromide with sodium tetrazolate and used as ligands in energetic coordination compounds (ECCs) and evaluated concerning their thermal and mechanical sensitivities. Furthermore, the two nitrogen-rich compounds 1-((1H-1,2,3-triazol-4-yl)methyl)-1H-tetrazole (TriMT, 3) and 1-((1-(2-(1H-tetrazol-1-yl)ethyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-tetrazole (TriMTET, 4) were prepared. Both were characterized by IR spectroscopy, NMR measurements, and low-temperature X-Ray diffraction analysis. Due to the highly endothermic enthalpy of formation of the propargyl-tetrazole ligands, powerful, yet relatively safe to handle, laser-ignitable ECCs were obtained.

Yang Liu, Yinglei Wang, Yuezhou Liu et al.

Boron powder is a kind of metal fuel with high gravimetric and volumetric calorific values, which has been widely used in military fields such as solid propellants, high-energy explosives, and pyrotechnics. However, the easily formed liquid oxide layer can adhere to the surface of boron powder and react with the hydroxyl (-OH) group of hydroxyl-terminated polybutadiene (HTPB) binder to form a gel layer that is detrimental to propellant processing and restricts the complete oxidation of boron powder. Therefore, to improve the combustion efficiency of boron powder, the ignition and combustion mechanisms of boron powder have been studied, and surface coating modification strategies have been developed by researchers worldwide, aiming to optimize the surface properties, improve the reaction activity, and promote the energy release of boron powder. In this review, recent studies on the ignition and combustion mechanisms of boron powder are discussed. Moreover, the reported boron powder coating materials are classified according to the chemical structure and reaction mechanism. Additionally, the mechanisms and characteristics of different coating materials are summarized, and the mechanism diagrams of fluoride and metal oxide are provided. Furthermore, promising directions for modification methods and the potential application prospects of boron powder are also proposed.

Takashiro Akitsu, Akinori Honda, Taiga Imae et al.

This review discusses conventional flame retardants for polymers and the possibility of using endothermal materials as flame retardants. Halogen-based, phosphorus-based, inorganic compounds, and their combinations are generally used as flame retardants for polymeric materials. The mechanism of action involves the trapping of radicals in the gas phase, an endothermic dehydration reaction, the blocking of oxygen, and a heat insulation effect by char in the solid phase. We discuss the possibility of using low-molecular-weight organic (or inorganic) metal complexes, exhibiting unique endothermic phenomena, such as phase transitions and cold crystallization, as flame retardants or thermal stabilizers at lower temperatures. In addition, this review provides an outlook on state-of-the-art) polymer flame-retardant technology.

Yunhe Jin, Wenquan Zhang, Zhiyu Zhou et al.

As a promising choice of new-generation green propellant fuels, hypergolic ionic liquids (HILs) have attracted a great deal of interest in recent ten years, illustrated by their applications in the field of space science and exploring outer space. The design and syntheses of new ionic liquids (ILs) are the basis of the HILs’ sustainable development. In the recent years, many new HILs have been created through the rational design, and their hypergolic property and applications have been studied extensively. With the aim of familiarizing the reader with new trends in the area of HILs research, in this review we present the latest developments of new HILs including syntheses, properties, structure-property relationship and their applications in the field of liquid bipropellants, while the debatable issues and future challenges that need to be addressed are also discussed. Through this review, we intend that more readers may learn about the newest trends in the field of ionic liquid propellants, and it may also provide an additional catalyst for the vigorous development of new-generation green space propellants.

Xia Zhao, Jinxin Wang, Yunhe Jin et al.

In this work, six energetic complexes were prepared and used as promoters for the hypergolic reaction of 1-ethyl-3-methylimidazolium cyanoborohydride [EMIM][BH3CN] and 90% H2O2. The structures of these compounds were studied by FT-IR spectroscopy, powder XRD, and single crystal X-ray diffraction. The results revealed that all the compounds were isostructural and each metal center was coordinated with four organic ligands and two counter ions. The decomposition temperatures of these compounds ranged from 169.6–255.9 °C. After adding 10 wt.% of prepared complexes to an ionic liquid, [EMIM][BH3CN], the shortest ignition delay time achieved was 94 ms. Moreover, the formed homogenous catalytic fuels had similar densities, thermal stabilities, as well as specific impulses similar to that of pure [EMIM][BH3CN]. The simple preparation method, excellent yield, as well as high performance of these compounds make them promising promoters for use in green hypergolic bipropellants.

Gabriele T. Muller, Alon Gany

This paper presents an investigation on a novel method for manipulating and enhancing the burning of solid fuels and propellants by expandable graphite additive. Expandable graphite (EG) is a form of intercalated graphite. At elevated temperature it undergoes an increase in volume, forming elongated strings/fibers many folds longer than the original particles/flakes. It was found experimentally that the addition of 1-5% of expandable graphite (original particle size 100-150 micrometer, onset of expansion at 200-230°C) to a polymeric fuel matrix (polyester) in hybrid combustion, increased the fuel regression rate by 2 fold and more. It was hypothesized that the EG strings forming near the burning surface protrude into the hot gas environment increasing heat transfer into the fuel via conduction. Furthermore, the swelling effect at the surface layer might increase the effective surface area, hence further increasing the burning rate. High-speed photography of a surface subjected to flame in oxidizing atmosphere showed EG fibers protruding and growing on the surface, supporting the increased heat transfer hypothesis. On the other hand, the addition of the same EG to an ammonium perchlorate-based propellant showed a tendency to reduce burning rate and even extinguish the flame at EG fractions higher than about 3-5%. It is concluded that in the case of hybrid or solid fuel ramjet combustion, EG can serve as a novel and effective burning rate enhancer while employing polymeric fuels of good mechanical properties in contrast to paraffin fuels which have inferior mechanical properties. The influence of EG on the combustion of solid propellants needs further investigation, looking for combinations of EG and propellant types that may exhibit a similar effect.

M. Bouziane, A.E.M. Bertoldi, P. Hendrick et al.

The showerhead is the most common type of injector used in hybrid rocket motors due to its design and manufacture simplicity. The main drawback of the showerheads (SH) is the relatively low performance in terms of combustion efficiency because of the poor atomization of the liquid oxidizer. This study investigates the problem to enrich the technical literature by presenting detailed experimental data on showerhead injectors by a series of static firing tests using a 1-kN lab-scale hybrid rocket, applying four kinds of showerhead injectors, named SH1 (benchmark), SH2, SH3, and SH4. They differ from each other by the number, distribution, and dimension of the orifice elements. Main performance parameters such as fuel regression rate, specific impulse, and combustion efficiency are experimentally obtained.Two different series of tests were carried out. At first, the influence of SH injector geometries was studied. The injectors SH2, SH3, and SH4 were used under the same initial conditions, and the results were compared with SH1. In the second set of tests, the SH4 injector was chosen, and the effects of the fuel grain initial port diameter were investigated. Using the data obtained in the second battery of tests was possible to determine the influence of the fuel port diameter on the motor efficiency and establish the regression rate law of nitrous oxidizer/paraffin-based fuel for this specific configuration.

Donghee Lee, Seongjoo Han, Heejang Moon

In this study, ground tests of a lab-scale hybrid rocket motor were conducted to verify the feasibility of the hybrid propulsion system for lunar lander application. The primary goal is to assess the realizability of hybrid rocket by testing its throttleability and soft landing capability with a scale-down lunar module. A design thrust of 200 N was achieved by clustering four identical 50 N-class gaseous oxygen (GOX)/high-density polyethylene (HDPE) hybrid rocket motors with multi-port solid fuels. Ground tests were carried out via two main experiments: static test and drop test. Static test was focused on the overall performance of the clustering module such as cold injection, uniform oxidizer distribution, throttleability and simultaneous ignition of the four motors, while the drop test was performed to investigate the planned throttle behavior using a 1-D vertical drop test stand. The clustering module was controlled in an open-loop setup with a simple ballistic flight simulation input. The landing velocity of 1.01 m/s was achievable, confirming the possibility of soft landing missions on lunar surface using hybrid rocket motors.