2022 Vol. 9, No. 5
Display Method:
Topic：Reusable Launch Vehicle
(Guest Editor:Professor SONG Zhengyu, China Academy of Launch Vehicle Technology)
2022, 9(5): 457-469.
doi:10.15982/j.issn.2096-9287.2022.20220021
Abstract:
A reusable launch vehicle can take off vertically and horizontally, and then land vertically, horizontally, or by parachute, so as to form various combinations of takeoff and landing schemes. Aiming at the different recovery modes of reusable launch vehicle, this paper discusses the key technologies of Vertical Takeoff and Vertical Landing (VTVL), parachute recovery, and Horizontal Takeoff and Horizontal Landing (HTHL), covering key technologies for other combinations. For VTVL mode, three key technologies, such as engine throttling, multiple start-up, and landing mechanism, are analyzed in detail. For parachute recovery, the technologies relating to the landing area control of rocket jettisons and aerial recovery are introduced. For the HTHL mode based on the rocket propulsion system, five challenges including the coupling mechanism under complex aerodynamic thermal environment, thermal protection, landing mechanisms, guidance and control, are discussed. The characteristics of the three recovery modes are briefly summarized and compared.
A reusable launch vehicle can take off vertically and horizontally, and then land vertically, horizontally, or by parachute, so as to form various combinations of takeoff and landing schemes. Aiming at the different recovery modes of reusable launch vehicle, this paper discusses the key technologies of Vertical Takeoff and Vertical Landing (VTVL), parachute recovery, and Horizontal Takeoff and Horizontal Landing (HTHL), covering key technologies for other combinations. For VTVL mode, three key technologies, such as engine throttling, multiple start-up, and landing mechanism, are analyzed in detail. For parachute recovery, the technologies relating to the landing area control of rocket jettisons and aerial recovery are introduced. For the HTHL mode based on the rocket propulsion system, five challenges including the coupling mechanism under complex aerodynamic thermal environment, thermal protection, landing mechanisms, guidance and control, are discussed. The characteristics of the three recovery modes are briefly summarized and compared.
2022, 9(5): 470-476.
doi:10.15982/j.issn.2096-9287.2022.20210110
Abstract:
Research on the scheme of the vertical landing mechanism of the launch vehicle was done and the design schemes of different landing mechanisms were analyzed and optimized through such methods as graph theory analysis and topology analysis. For a high reliability, the mechanism scheme of a single closed-loop chain was determined. To achieve the goal of a high efficiency, the relevant motion pair selection scheme was determined. Considering the simplification of mechanism energy and other factors, a new design scheme of landing mechanism based on mortise lock was proposed. The research results can provide reference and technical support for the development of the vertical landing mechanism of the reusable launch vehicle.
Research on the scheme of the vertical landing mechanism of the launch vehicle was done and the design schemes of different landing mechanisms were analyzed and optimized through such methods as graph theory analysis and topology analysis. For a high reliability, the mechanism scheme of a single closed-loop chain was determined. To achieve the goal of a high efficiency, the relevant motion pair selection scheme was determined. Considering the simplification of mechanism energy and other factors, a new design scheme of landing mechanism based on mortise lock was proposed. The research results can provide reference and technical support for the development of the vertical landing mechanism of the reusable launch vehicle.
2022, 9(5): 477-482.
doi:10.15982/j.issn.2096-9287.2022.20210109
Abstract:
Different from the current reusable launch vehicle landing leg recovery scheme, this paper proposes a rocket vertical landing recovery mechanism based on a ground arresting scheme. In the process of rocket vertical landing and descending, the comprehensive action of ground arresting cable and damper is used to accomplish rocket braking recovery. Through the simulation analysis and the verification of the principle prototype, the ground arresting mechanism complete the arresting and recovering of the launch vehicle under the conditions of normal landing point, horizontal offset and rotation, the overload and impact on the rocket structure are small, and the attitude is controllable. The research shows that the arresting recovery mechanism realizes safe and controllable recovery of the rocket body structure.
Different from the current reusable launch vehicle landing leg recovery scheme, this paper proposes a rocket vertical landing recovery mechanism based on a ground arresting scheme. In the process of rocket vertical landing and descending, the comprehensive action of ground arresting cable and damper is used to accomplish rocket braking recovery. Through the simulation analysis and the verification of the principle prototype, the ground arresting mechanism complete the arresting and recovering of the launch vehicle under the conditions of normal landing point, horizontal offset and rotation, the overload and impact on the rocket structure are small, and the attitude is controllable. The research shows that the arresting recovery mechanism realizes safe and controllable recovery of the rocket body structure.
2022, 9(5): 483-491.
doi:10.15982/j.issn.2096-9287.2022.20210152
Abstract:
The aerodynamic characteristics of the reentry stage of the first sub-stage of two vertical take-off and landing rockets based on grid rudder and glider are simulated and analyzed. The aerodynamic characteristics of the first sub-stage of two configurations are obtained. The flow structure characteristics of the sub-stage are analyzed, and the variation of aerodynamic characteristics with Ma number and angle of attack is studied. The results show that the axial and the normal force coefficient of the sub-stage with grid rudder first increase and then decrease with the Ma number. The axial and normal force coefficient of the sub-stage based on glider configuration decrease gradually with the increase of Ma number when Ma number is above 2 at small angle of attack. By comparison, the static stability of the sub-stage with grid rudder configuration is better than the sub-stage with glide configuration, ,which means that the sub-stage with grid rudder was more suitable for a mission requiring accurate control of the landing point. Meanwhile, the lift-drag ratio of the sub-stage with glider configuration is higher than that of the grid rudder configuration, indicating that the sub-stage with glider was more applicable for long distance gliding.
The aerodynamic characteristics of the reentry stage of the first sub-stage of two vertical take-off and landing rockets based on grid rudder and glider are simulated and analyzed. The aerodynamic characteristics of the first sub-stage of two configurations are obtained. The flow structure characteristics of the sub-stage are analyzed, and the variation of aerodynamic characteristics with Ma number and angle of attack is studied. The results show that the axial and the normal force coefficient of the sub-stage with grid rudder first increase and then decrease with the Ma number. The axial and normal force coefficient of the sub-stage based on glider configuration decrease gradually with the increase of Ma number when Ma number is above 2 at small angle of attack. By comparison, the static stability of the sub-stage with grid rudder configuration is better than the sub-stage with glide configuration, ,which means that the sub-stage with grid rudder was more suitable for a mission requiring accurate control of the landing point. Meanwhile, the lift-drag ratio of the sub-stage with glider configuration is higher than that of the grid rudder configuration, indicating that the sub-stage with glider was more applicable for long distance gliding.
2022, 9(5): 492-497.
doi:10.15982/j.issn.2096-9287.2022.20210116
Abstract:
Aiming at the control difficulties in the recover phase of a vertical landing of returning rocket, such as static unstable shape, elastic deformation of large slenderness ratio arrow body, liquid storage phenomenon for zero-pole, large interference of sudden change of aerodynamic shape during the deployment of landing, large-scale attitude adjustment, etc. Requirements and constraints of the critical vertical landing phase on the control system are analyzed comprehensively in this paper. Moreover, a high-precision attitude control scheme for vertical landing phase is put forward, that include parametric optimization design for large static instability and slosh-polar zero structure, nonlinear smooth gain scheduling, and high precision attitude control algorithm based on ESO. Simulations show that the design requirements can be accomplished by schemes proposed.
Aiming at the control difficulties in the recover phase of a vertical landing of returning rocket, such as static unstable shape, elastic deformation of large slenderness ratio arrow body, liquid storage phenomenon for zero-pole, large interference of sudden change of aerodynamic shape during the deployment of landing, large-scale attitude adjustment, etc. Requirements and constraints of the critical vertical landing phase on the control system are analyzed comprehensively in this paper. Moreover, a high-precision attitude control scheme for vertical landing phase is put forward, that include parametric optimization design for large static instability and slosh-polar zero structure, nonlinear smooth gain scheduling, and high precision attitude control algorithm based on ESO. Simulations show that the design requirements can be accomplished by schemes proposed.
2022, 9(5): 498-505.
doi:10.15982/j.issn.2096-9287.2022.20220035
Abstract:
Traditional reliability evaluation of liquid rocket engines requires a large number of verification samples. So the reliability evaluation method of reusable liquid rocket engine was studied. By analyzing the characteristics and failure modes of the instantaneous process of ignition for reusable rocket engines, and taking the instantaneous process of ignition as two independent processes (ignition process and transient development process), and the maximum entropy method and normal allowable limit method were evaluated individually. Meanwhile, the influence of reliability requirements and life shape parameters to total time of hot-fire tests, as well as the change of reliability with the number of tasks performed, were analyzed using the reliability evaluation method under study. It is shown that the proposed evaluation method can obtain higher reliability evaluation results with less test times. With the higher reliability requirements, the total time of hot-fire tests increases greatly; increasing the life shape parameters can greatly reduce the total time of hot-fire tests with the same reliability requirements; and the engine reliability decreases gradually with the increase of the number of tasks performed.
Traditional reliability evaluation of liquid rocket engines requires a large number of verification samples. So the reliability evaluation method of reusable liquid rocket engine was studied. By analyzing the characteristics and failure modes of the instantaneous process of ignition for reusable rocket engines, and taking the instantaneous process of ignition as two independent processes (ignition process and transient development process), and the maximum entropy method and normal allowable limit method were evaluated individually. Meanwhile, the influence of reliability requirements and life shape parameters to total time of hot-fire tests, as well as the change of reliability with the number of tasks performed, were analyzed using the reliability evaluation method under study. It is shown that the proposed evaluation method can obtain higher reliability evaluation results with less test times. With the higher reliability requirements, the total time of hot-fire tests increases greatly; increasing the life shape parameters can greatly reduce the total time of hot-fire tests with the same reliability requirements; and the engine reliability decreases gradually with the increase of the number of tasks performed.
2022, 9(5): 506-511.
doi:10.15982/j.issn.2096-9287.2022.20210144
Abstract:
Reusable launch vehicle is important to reduce the cost of launch service. This paper focuses on the modeling difficulty on the original fatigue load data of reusable launch vehicle engine. In this paper, the root mean square value is selected as the division standard for the original fatigue load data of the reusable launch vehicle. Original data are processed by modified short-time Fourier wave filtering, rain flow cycle counting and Gaussian distribution fitting for the identification and regularization of fatigue load data. Fatigue load data of reusable launch vehicle can be described by Gaussian distribution model. The Gaussian distribution parameter of abnormal fatigue load data is more than 3 times of normal fatigue load data. This method can be used to accurately identify the abnormal fatigue load data. Compared with traditional anomaly data identification methods, this method provides a quantitative index of abnormal data, which is a new analysis method for fatigue load design and real-time fault analysis and location of reusable launch vehicle.
Reusable launch vehicle is important to reduce the cost of launch service. This paper focuses on the modeling difficulty on the original fatigue load data of reusable launch vehicle engine. In this paper, the root mean square value is selected as the division standard for the original fatigue load data of the reusable launch vehicle. Original data are processed by modified short-time Fourier wave filtering, rain flow cycle counting and Gaussian distribution fitting for the identification and regularization of fatigue load data. Fatigue load data of reusable launch vehicle can be described by Gaussian distribution model. The Gaussian distribution parameter of abnormal fatigue load data is more than 3 times of normal fatigue load data. This method can be used to accurately identify the abnormal fatigue load data. Compared with traditional anomaly data identification methods, this method provides a quantitative index of abnormal data, which is a new analysis method for fatigue load design and real-time fault analysis and location of reusable launch vehicle.
2022, 9(5): 512-520.
doi:10.15982/j.issn.2096-9287.2022.20210146
Abstract:
Through a comparative analysis of multiple schemes, a reusable LO/LH propulsion-based single-stage lunar landing and ascent spacecraft scheme with vertical landing in horizontal attitude was proposed. For the problems of large fuel consumption and low control accuracy in braking phase, a convex-optimization-based guidance method was proposed. The convex optimization was then modeled and simulated, and the influence factors were analyzed. The results show that the scheme is easy to implement and reliable, capable of matching new-generation human launch vehicles, and the method possesses good mission applicability, enabling fuel cost optimization with various constraints including landing attitude and position accuracy. The proposed reusable single-stage lunar landing and ascent spacecraft scheme can be applied to lunar and cis-lunar reusable transportation missions, and provides a possible integrated transportation vehicle for both Earth orbit and lunar surface, holding a high cost-effectiveness ratio. The proposed scheme also provides a good solution for future transportation system for large-scale cis-lunar exploration and exploitation.
Through a comparative analysis of multiple schemes, a reusable LO/LH propulsion-based single-stage lunar landing and ascent spacecraft scheme with vertical landing in horizontal attitude was proposed. For the problems of large fuel consumption and low control accuracy in braking phase, a convex-optimization-based guidance method was proposed. The convex optimization was then modeled and simulated, and the influence factors were analyzed. The results show that the scheme is easy to implement and reliable, capable of matching new-generation human launch vehicles, and the method possesses good mission applicability, enabling fuel cost optimization with various constraints including landing attitude and position accuracy. The proposed reusable single-stage lunar landing and ascent spacecraft scheme can be applied to lunar and cis-lunar reusable transportation missions, and provides a possible integrated transportation vehicle for both Earth orbit and lunar surface, holding a high cost-effectiveness ratio. The proposed scheme also provides a good solution for future transportation system for large-scale cis-lunar exploration and exploitation.
2022, 9(5): 521-531.
doi:10.15982/j.issn.2096-9287.2022.20220028
Abstract:
The Moon is the nearest neighbor of the Earth and the first planet for human deep space exploration. Thus, the construction of long-term lunar research station will be great significant to further explore the deep space in 21st century. Mare Smythii is located at the junction of the lunar farside and nearside, and it is rich in the geological diversities and scientific values. In this paper, combined with the SLDEM 2015 elevation data, Clementine UV/VIS data, Kaguya MI data, and Chang'E-2 microwave radiometer data, the geological significance, topography, material composition, and microwave thermal emission features of Mare Smythii are thoroughly analyzed. Then, the region centered at (88oE, 1oN) is proposed for constructing the long-term lunar research station with high priority from the perspectives of scientific research, resources, and energy. Finally, three routes are outlined according to the surface topography, and 14 candidate exploring sites are planned aiming to scientific studies and resource utilizations. This study is of essential significance for the construction of the long term lunar research stations in future.
The Moon is the nearest neighbor of the Earth and the first planet for human deep space exploration. Thus, the construction of long-term lunar research station will be great significant to further explore the deep space in 21st century. Mare Smythii is located at the junction of the lunar farside and nearside, and it is rich in the geological diversities and scientific values. In this paper, combined with the SLDEM 2015 elevation data, Clementine UV/VIS data, Kaguya MI data, and Chang'E-2 microwave radiometer data, the geological significance, topography, material composition, and microwave thermal emission features of Mare Smythii are thoroughly analyzed. Then, the region centered at (88oE, 1oN) is proposed for constructing the long-term lunar research station with high priority from the perspectives of scientific research, resources, and energy. Finally, three routes are outlined according to the surface topography, and 14 candidate exploring sites are planned aiming to scientific studies and resource utilizations. This study is of essential significance for the construction of the long term lunar research stations in future.
2022, 9(5): 532-541.
doi:10.15982/j.issn.2096-9287.2022.20220017
Abstract:
Multi-satellite precision Orbit Determination and data Analysis Software in solar system (MODAS) is produced by the orbit dynamics group at the Science and Technology on Aerospace Flight Dynamics Laboratory. It provides an efficient and uniformed approach to perform orbit determination for spacecraft in solar system. In addition, it is aimed at solving the joint orbit determination of multiple spacecraft orbiting different celestial bodies, and can be used for both scientific application analysis and engineering practice. This paper describes the design and implementation of MODAS, including data organization and management, fundamental services, measurement models, and parameter estimation. Then, the implementation characteristics of MODAS are introduced in detail. The function is validated through the exploration data processing of the moon, Mars, Jupiter and asteroids. Finally, further application and improvements of MODAS is discussed.
Multi-satellite precision Orbit Determination and data Analysis Software in solar system (MODAS) is produced by the orbit dynamics group at the Science and Technology on Aerospace Flight Dynamics Laboratory. It provides an efficient and uniformed approach to perform orbit determination for spacecraft in solar system. In addition, it is aimed at solving the joint orbit determination of multiple spacecraft orbiting different celestial bodies, and can be used for both scientific application analysis and engineering practice. This paper describes the design and implementation of MODAS, including data organization and management, fundamental services, measurement models, and parameter estimation. Then, the implementation characteristics of MODAS are introduced in detail. The function is validated through the exploration data processing of the moon, Mars, Jupiter and asteroids. Finally, further application and improvements of MODAS is discussed.
2022, 9(5): 542-550.
doi:10.15982/j.issn.2096-9287.2022.20220012
Abstract:
The lightweight structure design of aluminum mirrors is a difficult problem in the complex optical mechanical system with multi-channel detection, large number of mirrors, strict requirements for volume and quality, cross folding of optical paths in space, short distance of optical components, and easy interference. Either traditional methods have high lightweight rate, but the process is complex, or the lightweight rate is limited. For solving these problems, a new structural design method of special-shaped lightweight aluminum reflectors for space spectrometer is proposed, which includes material selection, configuration design, assembly deformation unloading, lightweight design method, surface coating, detection and error compensation, The experimental verification of a space spectrometer shows that the lightweight rate of all aluminum mirrors designed by this method is better than 50%. The development and test of a space spectrometer show that all aluminum mirrors designed by this method can meet the requirements of the system, and the lightweight rate is better than 50%.This method can be applied to various types of space opto-mechanical systems involving aluminum mirrors, and can provide reference for aluminum mirror design and compact opto-mechanical system design.
The lightweight structure design of aluminum mirrors is a difficult problem in the complex optical mechanical system with multi-channel detection, large number of mirrors, strict requirements for volume and quality, cross folding of optical paths in space, short distance of optical components, and easy interference. Either traditional methods have high lightweight rate, but the process is complex, or the lightweight rate is limited. For solving these problems, a new structural design method of special-shaped lightweight aluminum reflectors for space spectrometer is proposed, which includes material selection, configuration design, assembly deformation unloading, lightweight design method, surface coating, detection and error compensation, The experimental verification of a space spectrometer shows that the lightweight rate of all aluminum mirrors designed by this method is better than 50%. The development and test of a space spectrometer show that all aluminum mirrors designed by this method can meet the requirements of the system, and the lightweight rate is better than 50%.This method can be applied to various types of space opto-mechanical systems involving aluminum mirrors, and can provide reference for aluminum mirror design and compact opto-mechanical system design.
