Launch Vehicle Research Articles

Применение оксидных покрытий, полученных экстракционно-пиролитическим методом, в космической технике

The problem of creating antimicrobial protection methods in rocket and space technology requires new approaches, in particular, the development of antibacterial coatings to protect the payload of launch vehicles. Also, in outer space outside the Earth's atmosphere, ultraviolet radiation with a wavelength of less than 280 nm (hard and vacuum ultraviolet) accelerates degradation of materials. It is relevant to create protective coatings for various materials used in space. An innovative extraction-pyrolytic method for producing oxide films containing copper, titanium and titanium oxide nanoparticles is considered. As a result, the compositions of effective antibacterial coatings with the function of protection against UV radiation have been established. The intended service and design features of the part on which the coating is applied are considered, and a flow diagram for applying an antibacterial coating to protect the internal volume of the fairing from bacteria circulating in the head of the launch vehicle is proposed. The possibilities of protection against UV radiation by applying oxide films to the outer surface of devices and rocket parts have been studied.

Визначення параметрів вібрацій космічного апарата на активній ділянці польоту ракети-носія на основі вогневих випробувань рiдинного ракетного двигуна

In orbital injection, the launch vehicle (LV) structure and the spacecraft are subjected to extreme dynamic loads, in particular to vibroacoustic loads (from rocket engine thrust oscillations and aerodynamic loads), which may cause spacecraft instrumentation malfunction and damage spacecraft light-weight thin-walled structures. This paper is dedicated to the development of an approach to predicting dynamic loads on spacecraft in orbital injection by LVs of various layouts under propulsion system thrust oscillations in active flight. The paper presents an approach to predicting dynamic loads on spacecraft in orbital injection by LVs of various layouts. The approach makes it possible to evaluate dynamic loads (spectral densities of vibration accelerations) on spacecraft under propulsion system thrust oscillations acting on the liquid-propellant LV structure in active flight. The approach includes a mathematical simulation of the spatial oscillations of the LV structure according to its structural layout scheme and the experimental pre-determination of the spectral density of the rocket engine power. The workability of the proposed approach in predicting the spacecraft dynamic loads is demonstrated by the example of a computational analysis of the spectral densities of spacecraft oscillations in orbital injection by LVs of various structural layouts. It is shown that the approach allows one to predict, as early as at the initial LV design stage, the spacecraft vibratory load parameters at different times of the LV first-stage liquid-propellant rocket engine operation accounting for the rocket layout (with the spacecraft) and design features and using the vibroacoustic characteristics of the liquid-propellant rocket engine (known from the results of its fire tests).

Визначення коефіцієнтов гідродинамічної моделі кавітуючих насосів рідин-них ракетних двигунів за їх теоретичними передатними матрицями

The characterization of cavitating pumps of liquid-propellant rocket engines (LPRE) is an important problem because of the need to provide the pogo stability of liquid-propellant launch vehicles and the stability of liquid-propellant propulsion systems for cavitation oscillations. The development of a reliable mathematical model of LPRE cavitating pumps allows this problem to be resolved. The goal of this work is to determine the cavitation number and operating parameter dependences of the coefficients of a lumped-parameter hydrodynamic model of LPRE cavitating pumps from their theoretical transfer matrices obtained by a distributed-parameter model. The following coefficients are found as a function of operating parameters: the cavitation elasticity, the cavitation resistance, the cavity-caused disturbance transfer delay time, and the cavitation resistance distribution coefficient. The last two coefficients are new in the hydrodynamic model of cavitating pumps, and they were introduced when verifying the model using experimental and theoretical pump transfer matrices. Analyzing the cavitation resistance distribution coefficient as a function of operating parameters shows that it markedly decreases with increasing cavitation number. This testifies to that the location of the lumped cavity compliance is shifted from the mid position towards the pump inlet. Therefore, the assumption that the lumped cavity compliance is located in the middle of the attached cavity regardless of the cavitation number is not justified. The fact that the distribution coefficient as a function of cavitation number intersects the abscissa axis near a cavitation number of 0.25 may indicate the boundary of existence of attached cavities and thus the applicability boundary of the theoretical model. The disturbance transfer delay time as a function of cavitation number sharply increases at cavitation numbers of about 0.05. At cavitation numbers of about 0.25, it is close to a constant.

Uncertainty Quantification of Artemis I Space Launch System Integrated Aerodynamics Databases

Accurate prediction of integrated aerodynamic forces and moments is a necessary part of aerospace vehicle development. This accuracy can be quantified in the form of an uncertainty model, which makes the prediction more useful within an integrated vehicle design effort. Aerodynamic force and moment databases were constructed for the Artemis I mission of the Space Launch System vehicle. These databases reconcile data from multiple sources to yield unified predictions of how NASA’s most advanced launch vehicle interacts with Earth’s atmosphere as it ascends into orbit. This paper outlines how the uncertainty quantification was performed for these databases to ensure comprehensive and tractable uncertainty source coverage.

A novel kriging-improved high-dimensional model representation metamodelling technique for approximating high-dimensional problems

Aiming to address the issue of the ‘curse of dimensionality’ encountered in approximating high-dimensional problems using surrogate-based methods, high-dimensional model representation (HDMR), decomposing the high-dimensional problem into summands of different-order component functions, has been widely studied. To reduce the computational demands of the current HDMR metamodelling techniques, an improved high-dimensional model representation framework (iHDMR) is presented, taking full advantage of the relationships between the first-order and second-order component functions in the Cut-HDMR theory. then, a novel metamodelling technique, termed kriging (KRG)-iHDMR, is implemented by integrating the kriging technique and the suggested surface-axes alternating sampling strategy into the iHDMR framework. The accuracy and efficiency of KRG-iHDMR are demonstrated by various numerical and engineering examples with different dimensions. Finally, an optimization problem of the multi-stage solid launch vehicle propulsion system is introduced to verify the engineering feasibility of the KRG-iHDMR metamodelling technique.

Architectural design space exploration of complex engineered systems with management constraints and preferences

During the architectural design phase, the decisions made have a crucial impact on developing complex systems. These decisions often limit the performance bounds and steer subsequent research directions. However, the multitude of architectural components and intricate interrelationships cause component combination explosion. Additionally, the diverse requirements of different stakeholders add complexity to determining the weight of indicators, posing challenges to complex system architecture generation and trade-off. This paper proposes a method for exploring the architectural design space in complex systems realisation, which aims to resolve issues related to the formal representation of architectures, selection within the architectural design space, and trade-offs. Firstly, the architectural design space is represented by formulating and mathematically describing a morphological matrix. Then, the construction of the Constraint Satisfaction Problem model aims to achieve a reduction in the scale of the design space. Moreover, through the evolutionary algorithm, the Pareto front is identified. Weight sensitivity analysis and the improved Technique for Order Preference by Similarity to the Ideal Solution method are combined to assist designers in finding a satisfactory architecture from the design space with many combinations. Finally, the proposed method is verified by the design of the launch vehicle’s primary and secondary separation system.

Numerical investigation on unstable oscillation of oxygen jet condensation in cryogenic liquid rocket

Oxygen jet condensation always occurs with intense unstable oscillation in the cryogenic delivery pipe of a space launch vehicle. This phenomenon threatens the safety of the propulsion pipeline. It is essential to explore the transient physical features of oxygen jet condensation precisely, including the spectrum of pressure oscillation. Aiming at a deeper understanding of the thermal hydraulic characteristic of oxygen jet condensation, abundant simulations are carried out using a modified phase change method. In this model, the height function method is introduced to capture the interfacial curvature to reveal the mechanism of periodic fluctuation. The simulation proves that three typical flow patterns are found at variant operating conditions in oxygen jet condensation: chugging, oscillation, and swinging. The condensation regime diagram is summarized according to the flow pattern distribution. The chugging flow, along with the phenomenon of liquid oxygen sucked-back flow, shows the most intense pressure oscillation with a maximum amplitude of 133 kPa. In the oscillation flow, the oxygen vapor plume shrinks periodically with a low frequency of about 10 Hz. The swinging flow is a stable flow pattern with a slight pulsation of oxygen vapor plume wake. Its amplitude of pressure oscillation is approximately 1–3 kPa. The influence of liquid oxygen mass flow rate and subcooling on the unstable characteristic is also obtained. These findings offer ample theoretical direction for the development of the space launch vehicle.

Analysis of Suitability of Fixed-wing Aircraft for Launching Satellites into Low Earth Orbit

The use of near-Earth space for scientific and commercial purposes has skyrocketed in recent years. However, progress continues to be hampered by the cost and availability of vehicles relied upon for delivering payloads to the Earth’s orbit. The Riga Technical University (Latvia), with the assistance of the Technological University in Kielce (Poland), is developing a concept of a novel payload launch system. The implications of such a system for launching payloads into low Earth orbit (LEO) are presented in the article. The system, intended for launching small spacecraft, comprises the A319 MPA transport airplane used as a platform aircraft and a three-stage payload carrier, codenamed LatLaunch. The first and second stages of the three-stage launch vehicle are unmanned winged aircraft. The third stage is a classic rocket which, once dropped from the launch platform, takes the payload to a specific height, at a given rate of speed and at a predetermined trajectory angle. The article presents the results of a study focusing on designing this system.

Launch Vehicle Integrated Health Management System Model

Launch Vehicle Integrated Health Management System Model

Features of mathematical modeling of nonlinear Pogo oscillations of launch vehicles

Features of mathematical modeling of nonlinear Pogo oscillations of launch vehicles

Effect of coarse second-phase particles on mechanical properties of large-scale 2219 Al alloy rings

Large-scale 2219 Al alloy rings are widely used as important parts on launch vehicles and thus have high requirements for the mechanical properties of rings in different direction, which are associated with coarse second-phase particles. Therefore, the objective of this study is to provide a comprehensive and systematic quantitative analysis of the effect degree of the coarse second-phase particles characteristics on the mechanical properties of 2219 Al alloy rings in different direction, so as to guide the design and optimization of the global process based on the relationship between each process and the coarse second-phase particles. Firstly, according to the features of the coarse second-phase particles characteristics in the experimental results, a reliable research scheme with the particles size, percentage and distribution as the study variable was designed. Then, based on the experimental characterization results, a representation volume element modeling method incorporating coarse second-phase particles characteristics was developed. The representation volume element finite element models for different research schemes were established in the ABAQUS/EXPLICIT platform respectively. Next, the comparison of experimental and numerical simulation results verifies that the finite element model with coarse second-phase particles developed in this paper can accurately predict ultimate tensile strength and elongation of the tested specimen. Finally, based on the numerical simulation results of the different research schemes, the effects of different sizes, percentages and distributions of coarse second-phase particles on the mechanical properties of the ring are analyzed to determine the extent to which the mechanical properties can be improved with different coarse second-phase particles characteristics. By exploring the relationship between the manufacture process, coarse second-phase particles characteristics and mechanical properties, the design and optimization of the manufacture process for different mechanical properties requirements are guided. This study is valuable in achieving comprehensive regulation of the mechanical properties of large-scale 2219 Al alloy rings.

Additive manufacturing of ceramic multi-material heating and ignition elements for a sustainable space access

The continuous advancement in the space industry and in space access has opened the doors to greater global participation and exploration, with numerous nations, institutes and companies now actively engaged in space exploration. This expansion owes much to the progress in commercial space technologies, such as reusable launch vehicles and micro satellites, which have significantly reduced the overall costs associated with space missions, thereby enhancing space accessibility.Nevertheless, to foster further growth, it is necessary to look at further options of making space access more sustainable and cost-effective. For that, it is important to investigate and identify the cost drivers. An example is the use of traditional manufacturing techniques and materials, which come with inherent limitations, notably in terms of design flexibility and performance efficiency. This results in solutions that are not only time-consuming to manufacture but also not the most effective, making it a costly process.To address these challenges, increasing emphasis is being placed on utilising alternative manufacturing methods, such as additive manufacturing technologies combined with high-performance ceramic materials. This aims to reduce the overall number of manufacturing steps for producing a component and to optimise complex and functional parts reducing the overall costs of mass-produced or individually manufactured components, as evident in current studies.The primary objective of this study is to enhance space accessibility through the development, production and optimisation of electrically functional, all-ceramic and multi-material components (heating/ignition elements). For that, the AM technology “CerAM MMJ” in combination with high performance ceramic material are utilised and discussed. Subsequently, these components undergo electrical measurements and tests, and the resulting data is presented and analysed in the following sections.The findings aim to shed light on the current state of the art and whether the additively manufactured, fully ceramic and electrically functional components could represent a more cost-effective alternative to conventionally manufactured components in the future.

Finite-time state-constrained adaptive fault-tolerant control for heavy launch vehicles with input quantization

This paper proposes the finite-time state-constrained adaptive fault-tolerant control method for a class of heavy launch vehicles subject to quantized input signals and actuator faults. Firstly, the attitude dynamic model of the heavy launch vehicles suffering from the actuator faults and disturbances is formulated. Secondly, to deal with the completely unknown nonlinear functions, radial basis function neural networks (RBFNNs) are introduced for approximation and compensation. Meanwhile, the barrier Lyapunov function (BLF) is introduced to ensure that all the states in the closed-loop system are bounded and the constraints of the system states are satisfied. As a result, the finite-time state-constrained adaptive fault-tolerant control structure is constructed for the heavy launch vehicles and the semi-globally practical finite-time stability (SGPFS) of the closed-loop control system is proved. Finally, numerical simulation results show the effectiveness and the satisfactory performance of the proposed control algorithm.

A mathematical method for the vibration analysis of composite lattice plates under In-plane compressive loads

Composite lattice structures are widely applied in launch vehicles due to their advantages of lightweight and high strength. When they are applied to propulsion systems, compression loads and vibrations must be considered. This study presents a mathematical approach for conducting vibration analysis of composite lattice plates under compressive loads in propulsion systems. This approach relies on a continuous model and the Ritz method and was derived to involve vibrations in a propulsion environment. The proposed method was verified by 3D finite element analysis, and parametric analysis was carried out to explore the impacts of compressive loads on the vibration characteristics. The results provide some general guidelines for the design of composite lattice structures for propulsion systems.

Government Policy or Market Mechanism, Which Is Better for Chinese Private Rocket Enterprises

In 2015, Chinese Government issued the<i> Notice on the National Civil Space Infrastructure Medium - and Long-Term Development Plan (2015-2025)</i>, announcing that it would support and guide social capitals to participate in the application and development of national civil space infrastructure construction. Later, Chinese private companies are allowed to apply for launch licenses, breaking the traditional model of allocating funds from the state budget and developing rockets only by the "national teams". Many Chinese private rocket companies were registered and established afterwards, and some of them have successfully launched rockets several times in recent years. At the same time, Chinese private rocket enterprises are also facing with many problems, including the low success rate of rockets, the risk of rocket debris falling, high space insurance rates, space junk, talent competition, and corporate survival, etc. In 2023, the Chinese Government issued <i>Notice on Strengthening the License Management for Civil Space Launch Projects</i>, which requires the third-party liability insurance policy and space debris mitigation plan for launch licenses application, meanwhile the last sub-stage of the launch vehicle should de-orbit according to the regulations after taking measures such as passivation, using government policy tools to regulate and guide the development of private rockets. In conclusion, in order to promote the healthy development of commercial launch service industry, the market mechanism should play a leading role, while appropriately regulation and adjustment from the government policy are also needed. In addition, this paper also suggested that the Chinese government should carry out overall planning for the division of labor and product models of state-owned and private rocket companies.

Cryogenic insulation performance of polyimide foam-filled fluted-core composite sandwich panels

Foam-filled composite sandwich structures have demonstrated superior thermal insulation performance, making them highly suitable for cryogenic tanks in launch vehicles. This study focused on the cryogenic insulation characteristics of carbon fiber-reinforced plastic (CFRP) fluted-core sandwich panels filled with polyimide foam. The fluted-core sandwich panel was simplified into a homogeneous multilayer plate to establish a one-dimensional heat transfer theoretical model. This model was used to predict steady-state temperature approximate solutions by linearizing the temperature-dependent thermal conductivity. The sandwich specimens were fabricated using an integrated forming co-cured method. Self-developed cryogenic insulation experiment and finite element simulations were conducted to acquire temperature distributions and validated the precision of the theoretical model. Results showed that the specimens achieved insulation temperature difference exceeding 143.05 °C, with effective thermal conductivity reaching 0.0326 W/(m·°C), significantly lower than that of CFRP. The temperature distributions along the thickness direction displayed a nonlinear increasing trend. The cryogenic thermal short effect was noticeable at the junction of the bottom facesheet and web. An analysis of geometric parameter influences revealed that increasing the short span, core height, or reducing web thickness could enhance thermal insulation characteristics with minimum effective thermal conductivity of 0.0276 W/(m·°C) and lead to a more uniform distribution of bottom temperatures with minimum temperature difference of 3.30 °C. These findings provide a foundational analysis for designing cryogenic insulation structures.

Comparison of Filtering Techniques for Transfer Alignment of Air Launched Tactical Guided Weapons

The transfer alignment technique is very useful for the accurate initialization and calibration of gyroscopes and accelerometers of INS for air-launched tactical guided weapon systems. In the present war scenario, the initialization of INS should be accurate and rapid to launch the tactical weapon against air or land targets within the shortest available time. A lot of development has been carried out by researchers for INS transfer alignment in the field of state estimation. The study and method presented in the research are relevant to aerial launch vehicles. However, to meet present guidance requirements within less time for initializing weapons, more appropriate transfer alignment algorithms are needed. This paper discusses the relative performance of Kalman Filter (KF), Extended KF, and Unscented KF for aligning the weapon INS using the data from Master INS. New developments, limitations, applicability, and design methods for the Kalman filters, became a key component in the transfer alignment of air-launched tactical missiles. These methodologies are extensively utilized in Navigation and Control systems; therefore, this research work will be an informative and perfect guide to existing and potential readers.

Configuration Synthesis and Grasping Performance Analysis of Multi-Loop Coupling Capture Mechanism for Launch and Recovery of Torpedo-Shaped Autonomous Underwater Vehicle

Configuration Synthesis and Grasping Performance Analysis of Multi-Loop Coupling Capture Mechanism for Launch and Recovery of Torpedo-Shaped Autonomous Underwater Vehicle

Korea Pathfinder Lunar Orbiter (KPLO) Operation: From Design to Initial Results

Korea Pathfinder Lunar Orbiter (KPLO) is South Korea’s first space exploration mission, developed by the Korea Aerospace Research Institute. It aims to develop technologies for lunar exploration, explore lunar science, and test new technologies. KPLO was launched on August 5, 2022, by a Falcon-9 launch vehicle from cape canaveral space force station (CCSFS) in the United States and placed on a ballistic lunar transfer (BLT) trajectory. A total of four trajectory correction maneuvers were performed during the approximately 4.5-month trans-lunar cruise phase to reach the Moon. Starting with the first lunar orbit insertion (LOI) maneuver on December 16, the spacecraft performed a total of three maneuvers before arriving at the lunar mission orbit, at an altitude of 100 kilometers, on December 27, 2022. After entering lunar orbit, the commissioning phase validated the operation of the mission mode, in which the payload is oriented toward the center of the Moon. After completing about one month of commissioning, normal mission operations began, and each payload successfully performed its planned mission. All of the spacecraft operations that KPLO performs from launch to normal operations were designed through the system operations design process. This includes operations that are automatically initiated post-separation from the launch vehicle, as well as those in lunar transfer orbit and lunar mission orbit. Key operational procedures such as the spacecraft’s initial checkout, trajectory correction maneuvers, LOI, and commissioning were developed during the early operation preparation phase. These procedures were executed effectively during both the early and normal operation phases. The successful execution of these operations confirms the robust verification of the system operation.

Safety analysis of evaluation and acceptance processes for space systems and operations based on system-theoretic approach

The proposed analysis consists of identifying systemic aspects that can influence safety and mission fulfillment in the Evaluation and Acceptance Processes of Space Systems and Operations for Launch through the application of System-Theoretic Process Analysis, a technique capable of identifying potential hazardous design and operational flaws, including system design errors and unsafe interactions among multiple procedures and system components. This research identifies losses, hazards, system-level safety constraints, the control structure of the general system, unsafe control actions, loss scenarios that could occur and related causal factors, detecting improvement possibilities for future verifications, evaluations, approvals, and acceptances of space systems and launch operations. These findings can promote safety in space system designs and operations, supporting the activities conducted by launch vehicle and payload developers, certification authorities, and launch centers management, enabling means to proactively act in order to mitigate risks, avoiding unsafe actions and undesired system behaviors, or even to mitigating their consequences. The practical applications of this work can result in safety and mission fulfillment improvements for safety management systems, launch approval regulations and standards; launch operation procedures; space systems design; vehicle, payload, and ground support equipment productions; systems testing; and launch authorization processes.