A new method for evaluating the firing precision of multiple launch rocket system based on Bayesian theory

How to effectively evaluate the firing precision of weapon equipment at low cost is one of the core contents of improving the test level of weapon system.A new method to evaluate the firing precision of the MLRS considering the credibility of simulation system based on Bayesian theory is proposed in this paper.First of all,a comprehensive index system for the credibility of the simulation system of the firing precision of the MLRS is constructed combined with the group analytic hierarchy process.A modified method for determining the comprehensive weight of the index is established to improve the rationality of the index weight coefficients.The Bayesian posterior estimation formula of firing precision considering prior information is derived in the form of mixed prior distribution,and the rationality of prior information used in estimation model is discussed quantitatively.With the simulation tests,the different evaluation methods are compared to validate the effectiveness of the proposed method.Finally,the experimental results show that the effectiveness of estimation method for firing precision is improved by more than 25%.

Rapid Launch of Medium-Sized Solid Carrier Rockets at Sea With High Reliability and Convenient Intelligence

Gravity-1 solid-propellant carrier rocket utilizes a three-vertical testing and launch mode, and adopts a sea-based launch method. As the demand for satellite launches continues to grow, the scarcity of launch site resources,and the consideration of cost savings, the need for rapid testing and launch of carrier rockets has become increasingly strong. The capability of rapid testing and launch has even become one important aspect of evaluating a rocket. This paper focuses on the characteristics of the Gravity-1 solid-propellant strap-on medium-sized carrier rocket and designs and implements a highly reliable, convenient, and intelligent low-cost rapid testing and launch solution. The main aspects include the design of a highly reliable dual-redundant ground architecture and the application of ground-based shelf products.

Commercial Aerospace: The Next Launchpad For the Chinese Economy

On December 29,2023,the first launch service tower was completed at the Hainan International Commercial Aerospace Launch Center,marking a key step forward in building the launch capacity of China’s first commercial aerospace launch site.On December 10,a Hyperbola-2 methane-liquid oxygen reusable verification rocket was launched successfully,marking the first recovery of reusable carrier rockets in China.

An efficient and modular modeling for launch dynamics of tubed rockets on a moving launcher

This paper develops a modular modeling and efficient formulation of launch dynamics with marching fire(LDMF)using a mixed formulation of the transfer matrix method for multibody systems(MSTMM)and Newton-Euler formulation.Taking a ground-borne multiple launch rocket systems(MLRS),the focus is on the launching subsystem comprising the rocket,flexible tube,and tube tail.The launching subsystem is treated as a coupled rigid-flexible multibody system,where the rocket and tube tail are treated as rigid bodies while the flexible tube as a beam with large motion.Firstly,the tube and tube tail can be elegantly handled by the MSTMM,a computationally efficient order-N formulation.Then,the equation of motion of the in-bore rocket with relative kinematics w.r.t.the tube using the Newton-Euler method is derived.Finally,the rocket,tube,and tube tail dynamics are coupled,yielding the equation of motion of the launching subsystem that can be regarded as a building block and further integrated with other subsystems.The deduced dynamics equation of the launching subsystem is not limited to ground-borne MLRS but also fits for tanks,self-propelled artilleries,and other air-borne and naval-borne weapons undergoing large motion.Numerical simulation results of LDMF are given and partially verified by the experiment.

A novel non-separation opening scheme of front cover for rocket launch canister

In view of that existing opening technologies of front cover for rocket launch canister have disadvantages such as causing damage on the ground equipment,not being reused and easily broken.A novel reusable non-separation spring-driven opening scheme is proposed to achieve rapid and reliable opening of the front cover.The mathematical model of the opening process of the front cover is established by the rigid body dynamics theory.To establish a response surface model to optimize the opening scheme,three main influencing factors of the opening process are obtained through the designed experiments,including the pre-compression,the stiffness of the thrust spring,and the thrust spring force arm length.In addition,the prescribed kinematic law was taken as constraint,and the smaller thrust spring preliminary pressure and angular velocity was taken as optimization expectations.The results show that the opening scheme meets the design requirements on opening process well.It also shows that the optimized scheme can reduce the kinetic energy of the front cover,and the impact on the canister effectively,achieving a reliable and rapid opening of the front cover.

Research on the Initial Ignition of the Underwater Launching Solid Rocket Motor

The aim of this investigation is to research the initial ignition of the underwater-launching solid rocket motor.The MIXTURE multiple-phase model was set to simulate the initial ignition.The water vaporization was researched and the energy transfer was added to the energy equations.The flow field and the vaporization were calculated coupled.The initial ignition process of the underwater solid rocket motor is obtained and the vaporization influence to the underwater launching is analyzed.The ＂neck＂,＂inverted jet＂ and ＂eruption＂ phenomenon of the bubble are observed.The bubble increases more rapidly because the steam mass added to the fuel.The temperature is lower considering the vaporization because the steam enthalpy is lower than the fuel enthalpy and the flow field of the initial ignition of the underwater-launching solid rocket motor is accordant well to the reference.

A novel launch dynamics measurement system for multiple launch rocket system and comparative analysis with numerical simulations

In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure from the muzzle)and the muzzle velocity are measured.Compared with the classical methods,the actual muzzle time is obtained by eliminating the ignition delay.The comparative analysis method is proposed with numerical simulations established by the transfer matrix method for multibody systems.The experiment results indicate that the proposed measurement system can effectively measure the actual muzzle time and reduce the error of classical methods,which match well with the simulation results showing the launch dynamics model is reliable and helpful for further analysis and design of the MLRS.

Ballistic Trajectory Extrapolation and Correction of Firing Precision for Multiple Launch Rocket System

The research on multiple launch rocket system(MLRS)is now even more demanding in terms of reducing the time for dynamic calculations and improving the firing accuracy,keeping the cost as low as possible.This study employs multibody system transfer matrix method(MSTMM),to model MLRS.The use of this method provides effective and fast calculations of dynamic characteristics,initial disturbance and firing accuracy.Further,a new method of rapid extrapolation of ballistic trajectory of MLRS is proposed by using the position information of radar tests.That extrapolation point is then simulated and compared with the actual results,which demonstrates a good agreement.The closed?loop fire correction method is used to improve the firing accuracy of MLRS at low cost.

Study on Feasibility of Reusable Rocket Launching Technology by Use of Scramjet and Maglev Technologies

The scramjet and maglev engineering technology development and trends at home and abroad are firstly presented in this paper. A new launch mode of space transportation system is proposed based on scramjet and magnetic suspension technologies, and its key technologies required are given. This paper also makes analysis on using scramjet and magnetic suspension technologies to launch a reusable rocket, and the results show that a normal temperature conductor maglev launch system is feasible.

Research on agile space emergency launching mission planning simulation and verification method

Space emergency launching is to send a satellite into space by using a rapid responsive solid rocket in the bounded time to implement the emergency Earth observation mission.The key and difficult points mainly include the business process construction of launching mission planning,validation of the effectiveness of the launching scheme,etc.This paper pro-poses the agile space emergency launching mission planning simulation and verification method,which systematically con-structs the overall technical framework of space emergency launching mission planning with multi-field area,multi-platform and multi-task parallel under the constraint of resource schedul-ing for the first time.It supports flexible reconstruction of mis-sion planning processes such as launching target planning,tra-jectory planning,path planning,action planning and launching time analysis,and can realize on-demand assembly of operation links under different mission scenarios and different plan condi-tions,so as to quickly modify and generate launching schemes.It supports the fast solution of rocket trajectory data and the accurate analysis of multi-point salvo time window recheck and can realize the fast conflict resolution of launching missions in the dimensions of launching position and launching window sequence.It supports lightweight scenario design,modular flexi-ble simulation,based on launching style,launching platform,launching rules,etc.,can realize the independent mapping of mission planning results to two-dimensional and three-dimen-sional visual simulation models,so as to achieve a smooth con-nection between mission planning and simulation.

Long March Rockets Complete 2018 Missions with 37 Record-Setting Launches

A LM-2D/Yuanzheng 3 launch vehicle successfully launched 6 Yunhai 2 satellites and one test microsatellite named'Chongqing'into their preset orbits,concluding China’s final orbital launch of2018.The launch took place at 16:00 Beijing time on December 29,2018 from the Jiuquan Satellite Launch Center.

Study on conditions of internally carried air-launched launch vehicles based on the virtual prototype technology

A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program.In this method,the full-scale model of the aircraft,the vehicle and the parachute are constructed.Then,they are imported into the ADAMS software,constraint solutions and driving forces are then added for visual dynamic simulation.The unsteady aerodynamic forces of the vehicle in the aircraft wake are calculated by CFD and the moving grid technique.The forces generated by the parachute can be derived from the Kirchhoff motion equation.Through comparing and analyzing the simulation results under different launch conditions,it has been proven that this method simulates the separation of a launch vehicle from the aircraft in the aircraft wake accurately.It provides the foundation for the aggregate project of internally carried air-launch vehicles,and offers a new referenced method for multi-body dynamic simulation.

LM-4B Rocket Launches the ZY-3 Satellite

At 11:17 on January 9,a LM-4B carrier rocket lifted off from the Taiyuan Satellite Launch Center,sending the first high-precision civilian stereo mapping satellite of China,Ziyuan 3 (ZY-3),into its preset orbit,marking the first launch mission of 2012 a success.A small satellite of Luxembourg,VesselSat-2,was launched aboard the LM-4B as well.The ZY-3 satellite weighs 2650kg with a design lifetime of 5 years.The satellite was built to acquire rapidly

Solid Rocket Motors for Launch Escape Tower Provide Safety to Astronauts

Compared with other ordinary launch vehicles, the LM-2F launch vehicle has two special systems, the fault detection processing system and launch escape system, because it is used for manned spaceflight missions. During the 10 flight missions carried out by LM-2F, only the

The First Launch of Europe-made Satellite by China's Rocket Achieved Great Success

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重复使用运载火箭液体动力技术发展

重复使用是未来运载火箭更新换代的技术发展趋势,是降低航天发射成本、实现规模化航天发射的有效途径。重点概述了国内外垂直起降重复使用运载火箭动力技术的发展现状,分析了垂直起降重复使用运载火箭发射和回收全任务剖面,总结了垂直起降重复使用运载火箭动力技术的特点,包括宽范围入口压力多次启动技术、大范围快速高精度推力调节技术、故障诊断及健康管理技术、状态检测与维修维护技术等。

空射诱饵弹对地面防空装备作战使用影响研究

空射诱饵弹(miniature air launched decoy,MALD)可诱骗地面防空雷达开机,消耗防空弹药,降低地面防空装备作战效能,提升空中编队突防能力。在梳理空射诱饵弹发展概况基础上,分析空射诱饵弹目标特性,构建典型作战运用场景,开展MALD对制导雷达探测跟踪性能和拦截效能影响分析,采用理论分析和动态仿真的方法研究了空射诱饵弹实施远距离欺骗、抵近干扰对制导雷达探测跟踪性能的影响,采用排队论方法分析MALD对空中编队突防效能的影响。研究结论可为空射诱饵弹战术运用提供参考。

液氧煤油火箭海上发射基本方案及关键技术分析

海上发射火箭在提升火箭运载能力、降低残骸坠落风险等方面具有极大优势。我国已成功实施多型固体火箭海上发射任务,相比固体火箭,液氧煤油火箭具有更高的比冲和环保性。根据液氧煤油火箭陆基发射的特点规律和固体火箭海上发射任务流程及实施方案,研究了海射系统港口基地、海上发射船、运载火箭、保障船等运行的基本方案,提出海上发射任务实施流程,分析了牵制释放、连接器零秒脱落和自动对接、无人值守推进剂加注技术在海上发射火箭中的重要意义,以及需要解决的关键技术难题。

考虑尾焰冲击的海上发射平台结构强度研究

海上发射平台具有移动性,可自由选择合适的发射海域,而火箭发射时的高温与冲击载荷会极大影响结构强度。针对某型海上发射平台,计算了7种水动力状态下,结构处于自航、自存以及发射工况下的强度。其中发射工况选取了点火瞬间、升空10 m以及升空30 m等3个时刻,并考虑导流槽的温度载荷与尾焰冲击载荷,同时考虑高温情况下板材许用应力的折减。计算结果表明,发射区域最大应力位于导流槽出口角隅处,对其原因做分析,为海上发射平台及其导流槽的设计提供了参考与建议。

基于NSGA-Ⅱ算法的ATR发动机PI控制器多目标优化方法研究

为了使空气涡轮火箭发动机(ATR)从慢车快速、稳定和准确地加速到最大状态,以ATR发动机燃气发生器流量和尾喷管喉部面积为控制变量,采用快速非支配排序遗传算法(NSGA-Ⅱ算法)建立了发动机控制器参数多目标优化方法。将超调量、稳态误差、上升时间及误差积分值四个指标以加权的形式作为目标函数,引入执行机构超调惩罚机制,建立了PI控制器参数Pareto最优解集,完成了ATR发动机从慢车加速到最大状态的动态过程仿真。结果表明,将双回路多个控制性能指标以加权的形式组合作为目标函数,可以获得均匀分布的Pareto前沿;联合应用多目标优化方法和基于熵权法的优劣解距离法(TOPSIS),能够在双回路耦合下获得满足设计要求的ATR发动机动态特性,极大地缩短了人工整定控制器参数的时间;在加速过程中,多目标优化方法将涡轮膨胀比上升时间作为目标函数之一,与尾喷管面积开环控制动态过程相比,可以使涡轮膨胀比更早到达目标值,共同工作线远离喘振边界。