Generation Of Launch Vehicles Research Articles

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).

X-ray tomography of failure behaviors of arc welded AA2219 joints under tensile and cyclic loading

As one of the main structural materials widely used for the new generation of launch vehicles, the tensile properties and microstructural characterization of tungsten inert gas (TIG) welded 2219 aluminium alloy has been studied extensively. However, there are significant differences between fatigue fracture and tensile fracture modes. In this paper, the tensile and fatigue damage behaviors of arc-welded AA2219 joints were investigated in depth. Combined with the microstructure observation and fracture analysis done by using X-ray computed tomography, the main factors that affect the fatigue damage behavior are discussed. The results show that there are a large number of porosity defects in the weld zone, showing an aggregation distribution at the weld toe and weld pool line. The fine-grain zone around the fusion line is the softening zone of the welded joint. For tensile conditions, the cracks were initiated at the softening zone and extended along the fusion line to the final fracture. Under fatigue loading conditions, the weld reinforcement leads to the stress concentration at the weld toe, and at the same time, a lot of pore defects at the weld toe, which causes crack initiation at the pores in the weld toe. Due to the small plastic zone at the fatigue crack tip, the crack propagates almost perpendicular to the loading direction in the heat-affected zone, driven by a mode I crack. A large number of gas pores in the weld zone have no substantial effect on fatigue crack propagation.

Study on Optimization of Chilldown Process for A New Generation Launch Vehicle

Focused on chilldown procedure of liquid oxygen filling for second stage of a new generation launch vehicle, the method of chilldown through liquid oxygen pump has been put forward and compared with traditional method that of gas pressurization. The results showed that it could reduce total time, lower system state changes, and improve efficiency and reliability of liquid oxygen loading operations. Aimed at liquid oxygen flow of chilldown through the pump, the model of liquid oxygen pump operating has been established by considering variable frequency, regulating valve opening and liquid level of vehicle tank. It can provide scientific guidance and basis for flow control of chilldown through the pump and liquid oxygen tests.

General Scheme and Key Technology of Long March 5 Launch Vehicle

Long March 5 (LM-5) is a new generation of heavy-lift launch vehicle developed by China. It has successfully completed the first Mars exploration of China and the 3rd phase of China lunar exploration program of Chang’E 5 (CE-5). LM-5 experienced 30 years of key technology research and engineering development. During this period, a lot of engineering technical problems were conquered, rich experience in the development of large cryogenic launch vehicle was accumulated, and the development of the new generation launch vehicle system was constructed. The research capability and foundation of carrier rockets have been greatly improved. This paper describes the development background of LM-5. Based on the overall rocket technical scheme and technical innovation, this paper discusses the development thinking of the rocket, the modular configuration scheme, the overall optimization design technology of the whole rocket and the structure technology of the large diameter and large concentrated load rocket body, and probes into the key technical problems of the LM-5 for the deep space exploration mission, specifically, the orbit design and optimization technology for deep space exploration mission, and narrow window multi-orbit launch technology. LM-5 is a landmark project of China’s new generation of launch vehicle, representing the highest level of launch vehicle technology of China, and is a significant symbol for China’s transformation from a major player in space to major power in space.

Сравнительный анализ параметров траектории ракет космического назначения «Союз-ФГ» и «Союз-2» этапа 1а на основе данных внешнетраекторных измерений

In order to identify the distinctive features of using analog and digital control systems, a comparative analysis of kinematic parameters of movement of two space rockets was carried out. Relying on the external trajectory measurement data, we developed a method for calculating the estimates of statistical characteristics of isochronous variations in the parameters of the state vector of the space rockets. Within the study, we compared and analyzed the kinematic parameters of the movement of Soyuz-FG and Soyuz-2 1a space rockets. Using the external trajectory measurement data, we calculated the spacecraft initial orbit parameters formed by the considered launch vehicles, and estimated their accuracy. Findings of research show that the parameters of the initial orbit formed by Soyuz-2 have smaller deviations from their nominal values, unlike the launch trajectory of the previous generation launch vehicle. Experimental data have confirmed the positive contribution of terminal control to reducing deviations of the implemented trajectory from the nominal one.

Research on attitude control strategy of single engine failure in the first-stage flight phase of new generation launch vehicle

The successful launching of the new generation of launch vehicle is of great practical significance to the development of China Space, and the cryogenic liquid engine commonly used in the launch vehicle has a certain probability of failures, which may affect the success or failure of rocket launching. In this paper, a Bolza problem optimization algorithm based on Radau pseudo-spectral method is proposed to solve the problem of single engine failure in the first-stage flight phase of the new generation launch vehicle by simulating fault injection and taking the attitude angle as optimal control quantity. The simulation results show that this method can effectively eliminate the influence of single engine failure on orbit injection accuracy, achieve the fault absorption of new generation launch vehicle engine, improve the fault tolerance of attitude control system, and further guarantee the system reliability.

Numerical Studies on Flowfield Characteristics of Four-Engine Rockets Impinging Jet with Different Flame Deflectors

[Objective] To explore the further deep space, many countries are developing the new generation launch vehicle which has higher effective loads [1, 2]. To upgrade capacity, a scheme with multiple engines working simultaneously has often been adopted in the propulsion system of heavy launch vehicles [3, 4]. Therefore, the rocket jet impact problem has been the vital factor which seriously affected the launch safety. Due to the rocket engines are close to the launch platform during launching phase, the exhaust jets of rocket engine not only disturb the attitude of rocket in the take-off, but also have a thermal impact on the rocket base and ground control system [5]. Potential dangers would threaten secure and stable of launch missions if these problems could not be solved properly. Therefore, carrying out research on the flow field characteristics of multi-engine rockets exhaust plume has a great significance for the risk aversion and improvement of achievement ratio in launching [6-9]. This paper researches the four-engine rockets flow field during launching phase, compares and analyzes the plume impact characteristics with two shapes of flame deflector by numerical simulation methods. [Methods] The study object of this paper is a three-stage liquid rocket which utilizes kerosene/liquid oxygen (LOX) propellant as propulsion system for the first stage. Structured meshes with tensor product structure have better numerical ability than unstructured grids that using a multi-block, structured mesh to improve the fidelity of the flow solutions and assure a good resolution of shock waves in the flow field. The liquid rocket exhaust is considered as an ideal gas with the continuum assumption. The numerical solution of the compressible, multi-species, Reynolds-Averaged Navier-Stokes equations for multi-component flow has been obtained with finite volume spatial discretization on a structured three-dimensional grid implemented. The supersonic jet impingement on deflector was computed the realizable k-ε turbulence model. The model has shown superior improvements over the standard-model where the flow features include strong streamline curvature and vortices. The accuracy and effectiveness of the impact model was verified by comparison between the calculated results and the measured date. [Results] The temperature, pressure, and contours on the symmetry plane with wedge-shaped and cone-shaped deflectors are obtained, three shock cells are established before the plume impacts the deflector surface. A high temperature region occurs immediately through excessive high temperature gas accumulation on the deflector surface. The core and developed region and boundary of plume are clearly visible downstream of flow field. The supersonic exhaust plume was diverted into outlet with two directions and circumferential direction in the wedge-shaped and cone-shaped flame deflector, respectively. It can be shown from the temperature and pressure contours in the deflector surface that the region of peak temperature and pressure occur directly under the rocket nozzle, and the temperature drops gradually from the center to the outlet of the flame deflector. The simulation results show the planar static temperature contours for the rocket motor gas impingement on wedge-shaped and cone-shaped deflectors at Z/D = 3, 4.5, and 6 in axial plume direction, where Z/D = 0 corresponds to the nozzle exit. The exhaust gas inlet of the wedge-shaped deflector has the same temperature as atmosphere except for jet flow region, and not affected by the reverse flow. The temperature edge region of planar in the cone-shaped deflector, as well as the central region, is much higher than ambient temperature. The temperature in the edge at Z/D =3 where is closest to the exhaust gas inlet may reach up to 800 K. [Conclusions] By comparative analysis between the four-engine rockets impinging jet on different deflector, the main conclusions are as follow. The region of peak temperature and pressure occurs directly under the rocket nozzle. The wedge-shaped and cone-shaped deflectors have different diversion directions. The maximum pressure and temperature in the wedge-shaped deflector are, respectively, 62% and 18% higher than those in the cone-shaped flame deflector. Compared with the wedge-shaped deflector, the cone-shaped deflector has better performance for deflecting, and increased the distance and optimized the structure of the sidewalls can further improve the exhaust gas flow conductivity. The results provide engineering guidance and theoretical significance for design of the flame deflector of the launch platform.The full version of this extended abstract will appear in Defence Technology in 2020.

Structural Integrity Assessment of a Propellant tank in Presence of Welding Residual Stresses

Upper stage of India’s new generation launch vehicle makes use of cryogenic propellants with liquid hydrogen (LH2) and liquid oxygen (LOX) as fuel and oxidizer respectively. The propellants are stored in tanks fabricated of Aluminum alloy and contain various openings. As carrying out proof test at operating environment is not feasible, the tanks are subjected to proof pressure test at room temperature (RT). During the RT proof pressure test of LOX tank, high strains, greater than 8000με, were recorded by gauges at three locations where weld rework had been undertaken. From structural analysis, the maximum welding residual stress at these locations is evaluated to be 95N/mm2. From stress analysis point of view, positive margins were observed with respect to failure of the tank even in presence of these residual stresses.However, since the tank is operating at cryogenic temperature, though there is an increase in the yield and ultimate strengths of the tank material, there is a reduction in ductility (lower percentage elongation). Therefore, evaluation of structural integrity of the hardware from fracture point of view is of paramount importance. A study was undertaken to investigate the influence of residual stresses on integrity of the tank in presence of minimum detectable crack sizes using conventional NDE techniques. The location where maximum strains were observed, post proof test, is considered for fracture evaluation. Directional stresses at location of interest are predicted through detailed finite element analysis. Subsequently, generalized Failure Assessment Diagram was drawn based on Elasto-Plastic fracture mechanics principles and margin against ultimate load ensured. The tank was used in a launch vehicle which was successfully flown in June 2017.

Development of China's New Generation Launch Vehicles

In the past 2 years, China's new generation launch vehicles, such as the LM-6, LM-7, LM-5 and LM-11 launch vehicles, successfully made the maiden flights, which marked Chinese Long March series launch vehicles having many achievements such as the diameter of launch vehicles increased from 3.35 m to 5 m and the toxic propellants replaced with non-toxic and pollution-free propellants. This paper will introduce the features and new technology of LM-7, LM-5 and LM-11 launch vehicles, which are China's new typical generation Launch vehicles.

Development of Cryogenic Engine for GSLV MkIII: Technological Challenges

Cryogenic engine capable of delivering 200 kN thrust is being developed for the first time in the country by ISRO for powering the upper stage of GSLV Mk-III, the next generation launch vehicle of ISRO capable of launching four tonne class satellites to Geo-synchronous Transfer Orbit(GTO). Development of this engine started a decade ago when various sub-systems development and testing were taken up. Starting with injector element development, the design, realization and testing of the major sub-systems viz the gas generator, turbopumps, start-up system and thrust chamber have been successfully done in a phased manner before conducting a series of developmental tests in the integrated engine mode. Apart from the major sub-systems, many critical components like the igniter, control components etc were independently developed and qualified. During the development program many challenges were faced in almost all areas of propulsion engineering. Systems engineering of the engine was another key challenge in the realization. This paper gives an outlook on various technological challenges faced in the key areas related to the engine development, insight to the solutions and measures taken to overcome the challenges.

Design and Analysis of a Metallic Ogive Payload Fairing for a New Generation Launch Vehicle

Launch vehicles are designed so as to travel through different layers of the atmosphere and thus are subjected to aerodynamic forces. Payload fairing, also known as heat shield is the topmost part of any launch vehicle. They are used to shield the satellites and payloads from the external atmosphere and aerodynamic forces. This paper focuses on the design and analysis of an ogive shaped payload fairing for new generation launch vehicle. Integrally stiffened panels are used as skins made of Aluminium alloy- AA2014. The design is carried out for a transonic regime Mach number of 1.2. Finite element modelling and analysis are carried out in NISA software. Based on the analysis results, mass optimization is carried out for the structure. Buckling margins and natural frequencies are estimated for the optimum configuration. A comparison with an existing composite payload fairing of similar configuration shows that their masses are comparable and hence can be considered as an alternate design option.

Augmentation of Classical and Adaptive Control for Second Generation Launch Vehicles

Augmentation of Classical and Adaptive Control for Second Generation Launch Vehicles

Classical Adaptive Augmentation Control for a Typical Second Generation Launch Vehicle

Abstract Classical control technique is used for attitude control of launch vehicles worldwide, because of its established history of success. Usual method is to model launch vehicle dynamics by linear techniques to achieve adequate stability and tracking performance. Common type of feedback control system for launch vehicles is the Proportional-Integral (PI) controller with appropriate filters to stabilize the lateral bending modes and slosh modes and also ensure sufficient robustness margins for rigid body. This paper presents a Classical Adaptive Augmentation Control (CAAC) Algorithm for forward loop gain augmentation in real time, to cater to large dispersion in vehicle parameters beyond the capability of classical control system. The idea is to provide augmentation to a classical control designed autopilot when performance enhancement is required to tackle off-nominal conditions arising out of modeling errors and large dispersion in estimated vehicle parameters (thrust, inertia, slosh, aerodynamics, lateral bending modes). There is high chance that such large dispersion can arise during initial design of a new generation launch vehicle before actual flight. Finally, validation of the Adaptive Augmentation Control design for several credible launch vehicle failure scenarios show that the adaptive controller consistently and predictably improves performance and robustness, and achieves stability during extreme off-nominal situations.

Progress of POGO suppression technology of launch vehicles at home and abroad

This paper describes the development process and progress of POGO suppression technology of launch vehicle at home and abroad, such as in the United States, the former Soviet Union, Europe, Japan and China. The characteristics of POGO suppression technology and inspirations of mini-POGO and cavitation dynamics are summed up. American POGO suppression technology has experienced the process of Titan 2—Saturn V—Space Shuttle—analysis of specific issues. Similarly, POGO suppression technology of China has also experienced the four stages of 331 project—Manned Spaceflight project—New generation launch vehicle—40Hz issue. It can be seen that POGO vibration suppression showed the following characteristics: difficult prior theoretical prediction, serious consequence and tortuous process of solution. It must be conducted research prior to the implementation of major aerospace project.

Soyuz in French Guiana: A strategic perspective

Abstract After a proposition from Russia to France, ESA agreed to see Soyuz rockets take off from French Guiana. From industry, to governments and agencies, many Russian and European actors were involved in this project and they all had different motives. It is therefore relevant to try to discern them so as to understand the rationale behind this cooperative endeavor. Soyuz's primary role is to consolidate Arianespace commercial position in the launching market and to bring activity and founding to a stagnating Russian space sector. With this decision Arianespace will have a full range of commercially available launchers with Soyuz completing the two European rockets Vega and Ariane V. But since Vega and Ariane must have the priority, there is a risk to see an insufficient launch rate for Soyuz, which would not satisfy the Russian partners. Commercial elements alone cannot justify the agreement. There is a larger strategic ambition behind. What is at stake is the future development of innovative launch systems. It is important for ESA to maintain an autonomous access to space and to maintain a dynamic and strong European propulsion industry. Cooperation with Russia can offer an increase of expandable rockets capabilities and can pave for the next generation of launch vehicles. Moreover, we can detect an interest in acquiring a system that has the potential for human space flight capacity. Finally, the decision to launch Soyuz from French Guiana was the conjunction of Russian and French national interests, which led to a complete redefinition of the relations between Europe and Russia. It is of strategic importance that we, Europeans, adapt to this evolution and understand the new place that Russia takes in our space sector.

The study on compatibility of polymer matrix resins with liquid oxygen

Liquid oxygen (LOX) polymer composite tank is very important in the development of next generation of launch vehicles. To study LOX compatible polymeric matrix resins, three kinds of epoxy resins were studied. LOX impact test was used to evaluate polymers’ compatibility with LOX. Thermogravimetric analysis was used to analyze polymers’ oxidation. It seemed that polymers with better anti-oxidation properties, characterized by lower oxidation weight gain, lower weight loss and lower flash point, behaved better LOX compatibility. Fourier transform infrared attenuated total reflection spectroscopy confirmed the chemical reactions during the LOX impact process on the surface of polymers were similar to the oxidation reaction in gaseous oxygen (GOX) at high temperatures, which indicated the chemical mechanism of LOX compatibility of polymers was just oxidation reaction. In this way, two new epoxy resins with desirable LOX compatibility were acquired by modification.

Representation Language for Evaluating Reusable Launch Vehicle Concepts

†Evaluation of launch vehicle concepts requires analysis by experts in vehicle sizing, trajectory, propulsion, subsystems, operations, cost, and reliability. A common data model is required to ensure consistent analysis across the various disciplines. This paper describes the development of the Launch Vehicle Language to support evaluation of Second Generation launch vehicle concepts. Vocabulary definition, development of data structures, and implementation in XML are discussed. Future enhancements to facilitate interdisciplinary data exchange are described.

NASA's Integrated Space Transportation Plan — 3 rd generation reusable launch vehicle technology update

NASA's Integrated Space Transportation Plan (ISTP) calls for investments in Space Shuttle safety upgrades, second generation Reusable Launch Vehicle (RLV) advanced development and third generation RLV and in-space research and technology. NASA's third generation launch systems are to be fully reusable and operation by 2025. The goals for third generation launch systems are to reduce cost by a factor of 100 and improve safety by a factor of 10,000 over current systems. The Advanced Space Transportation Program Office (ASTP) at NASA's Marshall Space Flight Center in Huntsville, AL has the agency lead to develop third generation space transportation technologies. The Hypersonics Investment Area, part of ASTP, is developing the third generation launch vehicle technologies in two main areas, propulsion and airframes. The program's major investment is in hypersonic airbreathing propulsion since it offers the greatest potential for meeting the third generation launch vehicles. The program will mature the technologies in three key propulsion areas, scramjets, rocket-based combined cycle and turbine-based combination cycle. Ground and flight propulsion tests are being planned for the propulsion technologies. Airframe technologies will be matured primarily through ground testing. This paper describes NASA's activities in hypersonics. Current programs, accomplishments, future plans and technologies that are being pursued by the Hypersonics Investment Area under the Advanced Space Transportation Program Office will be discussed.

Space-how far we have come, how far there is to go

Space systems are vital to our everyday activities, relaying communications and observing events and environments on Earth (even assisting in treaty verification), and greatly adding to our knowledge of distant regions of our universe. In 1996, the new U.S. space policy committed the nation to a stable space program, including the International Space Station, a new generation of launch vehicles, and a space science program involving robotic Mars investigations, comet, asteroid and planetary sample return missions, and long-term efforts to characterize planets orbiting other stars. As we begin the new millennium, we need courage and inspiration to continue explorations of our universe and push us onward to further adventures and discoveries in space, perhaps even taking us out toward the stars before the next millennium. Driven by curiosity, creativity, and restlessness, we may find in space the long-term future of our species.

Treatment of severe chronic pain in patients with bonemuscle diseases

Classical control technique is used for attitude control of launch vehicles worldwide, because of its established history of success. Usual method is to model launch vehicle dynamics by linear techniques to achieve adequate stability and tracking performance. Common type of feedback control system for launch vehicles is the Proportional-Integral (PI) controller with appropriate filters to stabilize the lateral bending modes and slosh modes and also ensure sufficient robustness margins for rigid body. This paper presents a Classical Adaptive Augmentation Control (CAAC) Algorithm for forward loop gain augmentation in real time, to cater to large dispersion in vehicle parameters beyond the capability of classical control system. The idea is to provide augmentation to a classical control designed autopilot when performance enhancement is required to tackle off-nominal conditions arising out of modeling errors and large dispersion in estimated vehicle parameters (thrust, inertia, slosh, aerodynamics, lateral bending modes). There is high chance that such large dispersion can arise during initial design of a new generation launch vehicle before actual flight. Finally, validation of the Adaptive Augmentation Control design for several credible launch vehicle failure scenarios show that the adaptive controller consistently and predictably improves performance and robustness, and achieves stability during extreme off-nominal situations.