Launch Vehicle Research Articles

Staging Optimization of Satellite Launch Vehicles: Application to a Microsatellite Launcher

Staging Optimization of Satellite Launch Vehicles: Application to a Microsatellite Launcher

Экономика космоса: глобальный контекст и опыт Франции

Various approaches to the space economy are considered, its components are highlighted. Space and the knowledge about it, being the bedrock of the space economy, are considered as a public good. The space economy as a factor of geopolitics and realization of sustainable development goals is an area of competition and cooperation for global actors. On the one hand, the leading role of the State and its expenditures now and next in space exploration and development is emphasized, on the other hand, the growing role of public and private companies’ partnership is gaining momentum, including commercial projects for launching people into space not only for research, but also for recreational purposes by reusable launch vehicles. The gap between the USA as a leader of the space economy and its competitors exploring and using space for civil and military purposes has been statistically proven. The traditional disparity between spending on civilian and military projects in space is shrinking, and the parity may be set by 2030. The key role of France – the leading country of the EU and of the countries of the ESA – in the genesis and development of the space economy in the West European part of the continent is revealed. Such an important role of France is largely due to the attention that has historically been paid to this sphere of the national economy, based on the use of nuclear technologies by the only nuclear power in the EU. The dynamics of the space economy is not in favor of France and Europe, largely due to insufficient financing (both public and private), with a great difference between European space budget and that of the USA and China. The conclusion is made that it is unlikely for France (and the EU) to bridge the gap with these leaders in the foreseeable future, despite the planned increase in investments for this innovative sector of the economy.

Multi criteria analysis of performance evaluation of launch vehicles in the space industry

Multi criteria analysis of performance evaluation of launch vehicles in the space industry

Zero Dynamic Active Suppression Control for Underactuated Reusable Launch Vehicles With Nonminimum Phase Property

Zero Dynamic Active Suppression Control for Underactuated Reusable Launch Vehicles With Nonminimum Phase Property

Numerical analysis on thermal environment of reusable launch vehicle during supersonic retropropulsion

Developing reusable launch vehicles (RLV) is an effective way to significantly reduce space transportation costs. However, in the return stage of the vehicle, especially the supersonic retropropulsion (SRP), the first stage is partially submerged in the hot exhaust plume and faces severe convective heating at the base plate and sidewalls. As a rule of thumb, the layout of nozzles at the rocket base significantly affects the heat load. In order to evaluate the influence of heat load under different nozzle configurations during SRP (33 km–22 km), the thermal environment of RLV was studied through numerical investigation for three typical nozzle configurations. Using Reynolds-averaged Navier–Stokes equations (RANS)-based computational methods and the k−ω SST turbulence model, the flowfield is characterized at different trajectory points during retropropulsion. Results showed that the high heat flux is mainly concentrated in the baseplate's center area and the sidewall's near base area during SRP. In general, activating engines in the radial position is beneficial for the thermal protection system of a reusable launch vehicle while the thrust is identical. Base heating primarily results from high-temperature counterflows due to plume interactions, while sidewall heating is predominantly a result of high-temperature recirculation zones generated by plume-induced flow separation. During the supersonic retropropulsion phase, the 3-nozzle-180°, a non-closed nozzle configuration, has significantly lower heat loads on the baseplate and the sidewall than that of the 4-nozzle-90° and the 3-nozzle-120°. In addition, reducing the number of engines is also an effective solution under the same conditions of thrust. Studying the layout of the working engine without changing the original layout has important guiding significance for improving the reusability and safety factor of the RLV.

Multisensor Integrated Autonomous Navigation Based on Intelligent Information Fusion

A major inadequacy of the Kalman filter is the necessity of accurate measurement models, which may not be possible in the case of complicated disturbances. A new solution to multisensor integrated autonomous navigation based on intelligent information fusion technology for launch vehicles is proposed in this paper, which can improve navigation performance based on the existing measurement models. Artificial neural networks (ANNs) are designed to discover the hidden relationship between the available data and trajectory parameters. The tracking, telemetry, and control system can provide centimeter-level accuracy of the launch vehicle after every flight. While postprocessing data is irrelevant to real-time navigation using traditional methods, it is crucial for ANNs to learn the rules of information fusion and identify the inaccuracy of the input variables. In this way, artificial-intelligence-modified trajectory parameters are expected to be closer to the truth value. The experimental results indicate that the proposed method can significantly improve navigation performance compared with the unscented Kalman filter, and ANNs can achieve good performance in various situations.

Mission Performance Assessment of the Recovery and Vertical Landing of a Reusable Launch Vehicle

This paper focuses on the mission analysis of the return trajectory of a Vertical Landing Reusable Launch Vehicle, both for Return-to-Launch-Site (RTLS) and DownRange Landing (DRL) recovery strategies. The main objective is to assess the mission performance of propellant-optimal re-entry and landing trajectories from the Main Engine Cut-Off (MECO) while considering propellant budget and peak entry conditions constraints. As a result, performance envelopes and feasibility regions are built to comprehensively assess the required propellant and compare recovery strategies across a broad spectrum of MECO conditions. The results show that the DRL strategy achieves higher efficiency concerning the propellant consumption and a larger robustness regarding the dispersed MECO conditions.

Cost estimation for launch vehicle families considering uncertain market scenarios

When optimizing the staging of a launch vehicle, usually a reference mission with a fixed payload mass is used to determine the specific launch cost (or a surrogate thereof, e.g. total mass or dry mass). While this approach neglects suboptimal loading, it delivers sufficiently good results for the evaluation of an individual launcher if the design mission is well known. However, this approach does not capture the full range of payloads that a launch vehicle is expected to launch during its operational lifetime. In order to estimate the cost and subsequently optimize the staging of such launch vehicle families, a full launch scenario has to be considered. The cost of an individual launch vehicle loses importance and the deciding factor is the total cost associated with launching the specified scenario. However, estimates of the future market inevitably include large uncertainties. These uncertainties and their impact are ideally considered and quantified when assessing the specific recurring cost of a single launch vehicle. The consideration of a whole launch market scenario is especially relevant when evaluating a family of launch vehicles, an option currently being discussed for future European launchers. In this case, the distribution of the payloads onto the different members of the launch vehicle family has to be optimized in order to reach the lowest possible cost. Within this manuscript, a method that allows the determination of the recurring cost of such a launcher family based on a launch market scenario including uncertainties is proposed. Based on the launch numbers derived from the combinatorial optimization, parametric cost models for recurring and non-recurring cost are adapted and applied to three possible future launch vehicle families.

Global adaptive neural network control of nonlinear time-varying systems with unknown control coefficients and model uncertainties

This paper investigates the adaptive control problem for the strict-feedback nonlinear time-varying system (NTVS) with unknown control coefficients and model uncertainties. To address the problem that the neural network (NN) can only achieve local approximation of unknown nonlinear functions, a novel NN control scheme is proposed. The scheme consists of a NN controller that operates inside the approximation domain and a robust controller that operates outside the approximation domain, and a novel switching function is designed to enable the two controllers to switch smoothly in the vicinity of the approximation domain to ensure that all signals of the closed-loop system are globally uniformly ultimately bounded. To address the problem that unknown time-varying control coefficients are difficult to handle, an adaptive fault-tolerant control scheme is proposed in combination with the congelation of variables method. The scheme employs classical adaptive control to adapt to the variation of unknown control coefficients and robust control to eliminate the time-varying disturbance terms, and introduces a positive integrable time-varying function to achieve asymptotic tracking of an arbitrary reference signal. The combination of these two schemes constitutes a global adaptive neural network control (GANNC) method for the NTVS with unknown control coefficients and model uncertainties. Finally, an adaptive attitude fault-tolerant controller for launch vehicles is designed by using the GANNC method, which can realize the accurate tracking of the attitude control system to the reference command under normal status, strong disturbances and actuator failures, and comparative experiments prove the effectiveness and superiority of the controller.

Compensated acceleration feedback based active disturbance rejection control for launch vehicles

In this paper, the attitude tracking and load relief control problems against wind disturbances and uncertain aerodynamics as well as the engine thrust of launch vehicles are studied. Firstly, a framework of Compensated Acceleration Feedback based Active Disturbance Rejection Control (CAF-ADRC) is established to achieve both desired attitude tracking and load relief performances. In particular, the total disturbance that includes the effects caused by both aero-coefficient perturbations and disturbances is estimated by constructing an Extended State Observer (ESO) to achieve attitude tracking. Furthermore, combined with the normal acceleration due to the engine thrust, the accelerometer measurement is also compensated to enhance the load relief effect. Secondly, the quantitative analysis of ESO and the entire closed-loop system are studied. It can be concluded that the desired attitude tracking and load relief performances can be achieved simultaneously under the proposed approach. Besides, tuning laws of the proposed approach are systematically given, which are divided into ESO, Proportional Derivative (PD) and Compensated Acceleration Feedback (CAF) modules. Moreover, the performances under CAF-ADRC approach can be better than those under CAF based PD (CAF-PD) approach by tuning load relief gain. Finally, the approach presented is applied to a typical control problem of launch vehicles with wind disturbances and parameter uncertainties.

Flame structure of GCH4/GOX pintle model combustor with wall confinement

The pintle injector is a representative option for designing a throttleable rocket engine that can be applied for various applications, including the vertical soft landing of reusable launch vehicles. Although the most direct research method to investigate the characteristics of pintle injectors experimentally is the high-pressure combustion test, it is often limited due to its cost and operational hazards. Consequently, atmospheric combustion or cold flow tests are frequently applied in the rocket injector field to simulate and study the fundamental combustion or spray characteristics. However, previous works, including such simulated experiments under atmospheric conditions, involved an unrealistically wide combustor or open condition. Since only a single pintle injector is typically used per engine, the combustor wall may significantly influence the fundamental characteristics. Thus, in this study, a pintle injector combustor with adequate wall confinement is designed, and its flame structure is investigated across a wide range of total volume flow rates and mixture ratio conditions, incorporating several geometries with varying gaseous oxygen injection areas. This research primarily focuses on the flame structure and its angle. Under specific experimental conditions, the unreported unstable flame was newly observed. The overall experimental results, supported by numerical methods, indicate that wall confinement has substantial importance in simulating a realistic flame structure and internal flow field within the combustor.

Direct quantification of 1,1-dimethylhydrazine transformation products in sandy soil by thermal desorption gas chromatography – Tandem mass spectrometry

The use of rocket propellants based on unsymmetrical dimethylhydrazine (UDMH) in launch vehicles and boosters poses a threat to the environment due to the release of UDMH into soils and its subsequent transformation into a variety of nitrogen-containing compounds, including toxic and carcinogenic ones. The present proof-of-concept study proposes a novel approach to screening and simultaneous determination of a wide range of nitrogen-containing UDMH transformation products in soils, based on direct thermal desorption (TD) as a solvent-free sample extraction technique coupled with GC–MS/MS analysis.Optimal TD conditions consisting of the incubation of 5 mg sample at 300 °C for 30 min, allowed attaining high recoveries (80–100 %) for the most tested compounds and developing the method for quantification of fifteen acyclic and heterocyclic UDMH transformation products in sandy soil with LODs of 0.3–7.8 µg kg−1. The matrix matched calibration and introduction of the internal standard (pyridine‑d5) ensured high accuracy (75–100 %) and precision (RSD < 15 %) of the analysis. Along with high sensitivity and accuracy, the main advantages of the developed method are exceptional simplicity of sample preparation, low amount of toxic sample, high automation degree, and environmental friendliness.The developed method was successfully tested in the analysis of seven real soil samples taken from the Baikonur cosmodrome operational zone (Kazakhstan). The use of TD-GC–MS analysis in full spectrum scanning mode allowed for tentative identification of 62 UDMH transformation products including several compounds not yet described in the literature.

Concept of operations for the Neptune system mission Arcanum

AbstractThe Arcanum mission is a proposed L-class mother-daughter spacecraft configuration for the Neptunian system, the mass and volume of which have been maximised to highlight the wide-ranging science the next generation of launch vehicles will enable. The spacecraft is designed to address a long-neglected but high-value region of the outer Solar System, showing that current advances make such a mission more feasible than ever before. This paper adds to a series on Arcanum and specifically provides progress on the study of areas identified as critical weaknesses by the 2013–2022 decadal survey and areas relevant to the recently published Voyage 2050 recommendations to the European Space Agency (ESA).

Study of passive steering mechanism for small Mars surface exploration rovers

Planetary surface exploration rovers are required to have the ability to travel over uneven ground such as sandy or rocky terrain. In addition, to maintain long-term functionality under severe mass constraints, the rover must be highly reliable with a simple configuration. The reduction in the number of actuators will also contribute to a reduction in the number of electrical components involved and improve reliability. This paper proposes a lightweight and simple traveling and steering mechanism that combines a path-following system based on the difference in rotational speed of the left and right wheels when traveling in a curve and a passive Ackermann mechanism without an actuator, assuming a small exploration rover of a size and mass that can be mounted on a Japanese launch vehicle. We also propose a correction method to improve the path-following performance. We also developed a prototype wheeled rover of the target size and weight, and tested and evaluated the effectiveness of the proposed method in following the target path and overcoming obstacle on simulated soil.

К вопросам транспортировки гептила железнодорожным транспортом

Purpose: To estimate the properties of heptyl and its effect on the human body and the environment. To provide an overview of the sphere of heptyl application and the features of its transportation by rail. To consider the structural features of the model 15-629 tank car and to perform a calculation to select the optimal crosssectional area for the inlet opening of the relief valve to enhance safety during the transportation of heptyl by the model 15-629 tank car. Methods: To calculate the inner and outer surface areas of the tank shell using the technical characteristics of the six-axis multi-unit tank-car of model 15-629. Next, we will calculate the mass air flow rate through the inlet relief valve and determine the heat transfer occurring due to the external heat dissipation from the tank shell into the surrounding environment. These data are necessary to estimate the equivalent diameter of the inlet relief valve orifice. Results: Thanks to the calculations performed, a more suitable diameter of the inlet safety valve orifice has been determined. This will ensure a safer transportation of highly toxic liquid rocket fuel components used in both Russian launch vehicles (“Kosmos”, “Cyclone”, “Proton”) and international ones (such as American “Titan” rockets, French launch vehicles of the “Ariane”, Chinese rockets of the “Long March” family, and others). Practical significance: Hydrazine-based propellants are more energy-efficient compared to hydrocarbon-based propellants, which has led to an increased usage of Unsymmetrical Dimethylhydrazine (UDMH) in recent years. Due to the rapid growth of space industry, the volume of heptyl transportation by railway has been increasing. In order to prevent technological disasters, calculations have been conducted to determine the diameter of the inlet relief valve to minimize depressurization of the tank car, regardless of temperature conditions.

Vibration Suppression of a Flexible Beam Structure Coupled with Liquid Sloshing via ADP Control Based on FBG Strain Measurement

In this study, an adaptive dynamic programming (ADP) control strategy based on the strain measurement of a fiber Bragg grating (FGB) sensor array is proposed for the vibration suppression of a complicated flexible-sloshing coupled system, which usually exists in aerospace engineering, such as launch vehicles with a large amount of liquid propellant as well as a flexible beam structure. To simplify the flexible-sloshing coupled dynamics model, the equivalent spring-mass-damper (SMD) model of liquid sloshing is employed, and a finite-element method (FEM) dynamic model for the beam structure coupled with the liquid sloshing is mathematically established. Then, a strain-based vibration dynamic model is derived by employing a transformation matrix based on the relationship between displacement and strain of the beam structure. To facilitate the design of a strain-based control, a tracking differentiator is designed to provide the strains’ derivative signals as partial states’ estimations. Feeding the system with the strain measurements and their derivatives’ estimations, an ADP controller with an action-dependent heuristic dynamic programming structure is proposed to suppress the vibration of the flexible-sloshing coupled system, and the corresponding Lyapunov stability of the closed-loop system is theoretically guaranteed. Numerical results show the proposed method can effectively suppress coupled vibration depending on limited strain measurements irrespective of external disturbances.

The Dynamics of the Prevalence of Diseases Among Women of Fertile Age in the Charyshsky District of the Altai Region, Living Near the Fall Areas of Separable Parts of Launch Vehicles

Part of the territory of the Altai Region is involved in rocket and space activities as fall areas of separable parts of launch vehicles. This creates a number of specific problems for the ecological situation and the population living near the fall areas. Taking into account the aggravated demographic situation in Russia, this paper presents a dynamic analysis of the prevalence of diseases among women of fertile age in the Senteleksky village Council of the Charyshsky district, as a territory adjacent to the zone of rocket and space activities. The results of the medical examination of the population in 1999, 2006, 2011 and 2015 were used in the work. The most significant diseases and features of the dynamics of the prevalence of classes of diseases and individual nosologies were identified.

A novel re-entry trajectory design strategy enforcing inequality and terminal constraints in height-velocity plane

A novel re-entry trajectory design approach for a winged reusable launch vehicle that satisfies path and terminal state constraints in the height velocity plane is proposed in this paper. A two-phase re-entry trajectory is proposed. A height-velocity plane entry corridor is designed using all path and quasi-equilibrium glide constraints. The proposed method creates the reference trajectory inside the re-entry corridor using three piecewise polynomials, such as linear and logarithmic. A two-parameter search optimization problem minimizes terminal range-to-go error for this reference trajectory generation problem. Improved Search Space Reduction solves this optimization problem. The Improved Search Space Reduction algorithm is compared to the Grey Wolf Optimizer and Particle Swarm Optimisation algorithms to prove its efficacy and superiority. The reference bank angle is modified using feedback linearization and bank reversal logic to create an entry trajectory that meets all path and terminal constraints. The effectiveness of the proposed method has been validated through Monte Carlo simulations that incorporate uncertainties such as variations in initial state, uncertainties in aerodynamics, and atmospheric perturbations. The controller OPAL-RT OP4510 provides bank angle command at every instant based on the current state of the vehicle parameters associated with real-time simulator OP4510. The real-time hardware-in-loop simulation results show that the obtained re-entry trajectory satisfies all path and terminal constraints.

ASSESSMENT OF THE POSSIBILITY OF USING POLYMERS IN THE BODIES OF PROMISING LAUNCH VEHICLES BASED ON THE HEAT RESISTANCE FACTOR

One of the possible ways to solve the problem of quick and low-cost payloads to low Earth orbits is the creation of ultralight rockets that use new construction materials, in particular, synthetic polymers. A promising approach to creating a launch vehicle of this type is the concept of a burnt rocket, the body of which is made of thermoplastic polymer materials. At the same time, the practical implementa- tion of such a launch vehicle requires additional research, in particular, the possible process of premature destruction of the structure due to aerodynamic heating. In this work, the heat resistance of polymer bodies of a new type of ultralight launch vehicles during flight in the atmospheric part of the trajectory was evaluated. For mathematical modeling of heating processes, we used the results of experimental studies of the thermodynamics of polyethylene and polypropylene during heating. These results allowed us to propose a mathematical model for calculating the process of heating polymer shells. The dynamics of the temperature fields during movement along the given trajectory of the launch vehicle in the atmospheric stage have been determined. It was established that under the given trajectories, both considered materials satisfy the conditions of heat resistance. The influence of temperature on the reduction of the strength characteristics of polymer bodies is shown, and the necessary thicknesses of the walls of the body shells, which should prevent deformation of the structure during aerodynamic heating, are determined. So, for the first time, the possibility of making rocket bodies from thermoplastic polymer materials has been theoretically substantiated.

BIFURCATION STATE AND RATIONAL DESIGN OF THREE-LAYER REINFORCED COMPOUND CONE-СYLINDER SHELL STRUCTURE UNDER COMBINED LOADING

An analytical-numerical approach to solving the problem of state bifurcation in terms of local and overall stability of a three-layer cone-cylinder shell structure discretely supported by intermediate rings, in particular of modern launch vehicles, under static combined loading by external pressure, axial forces, and torque is proposed in the paper taking into account the stiffness parameters of the intermediate rings in the plane of the initial curvature and for torsion. Corresponding solving equations for the problem are ordinary differential equations of the sixth order (for a cylindrical compart- ment with constant coefficients and for a conical one with variable coefficients along the axial coordinate). Differential relations that determine the conditions of conjugation through the intermediate ring are used. For the numerical solution, the finite difference method is used with central finite differences of the third and second order at the inner points of the shell determination segments and at its ends, respectively, and the second order differences with one step backward or forward at the conjugation points through the ring. The agreement of the calculation results with the known data for three-layer conical and cylindrical shells is shown, as well as in the limiting case, it is done when passing to a single-layer compound cone-cylinder structure. For the considered class of cone-cylinder shell structures, boundary surfaces are constructed that separate the stability region of the structure being under study, depending on the geometric and stiffness parameters of the compartments, reinforcing elements, and the external load condition. The external load effect on the parameter of the post-critical wave formation for the structure under investigation is studied, provid- ing the visualization of the deformation behavior. The analysis of the calculation results has shown that this approach to solving the problem of bifurcation and equistability of the compound structure compartments in relation to the local and overall forms of protrusion allows choosing rational geometric and stiff- ness parameters of the shell components and force elements in terms of improving the weight characteristics of the structure.