The German space processing programme TEXUS with sounding rockets

This paper reports on the objectives of the German space processing programme with sounding rockets and the scientific results obtained thus far.     

German rockets in africa: The explosive heritage of peenemunde

This historical paper reviews the technical development and the political impact of two “intelligence affairs” with German rocketry in African countries: 1. the Nasser missiles and space projects in Egypt during the 1960s; 2. the private OTRAG venture in Zaire and Libya during the 1970s.     

Combustion characteristics of the end burning hybrid rockets in laminar flow

In this study, we aim to clarify the blowoff mechanism for flame spreading in an opposed laminar flow in narrow solid fuel ducts. To clarify this mechanism we conducted two experiments. First, we observed the changes of the flame spread rate at various oxygen velocities, ambient pressures, and port diameters. For flame spreading in laminar flow, combustion modes could be classified into 3 distinct regimes based on the strength of the opposed flow, i.e., chemical regime, thermal regime, and stabilized regime. This result is consistent with the result in turbulent flow. In the stabilized regime, quenching distance is almost constant despite oxygen velocity. In order to investigate the effect of ambient pressure and port diameter of fuels on blowoff limit, transition oxygen velocity is observed. As a result, transition oxygen velocity is proportional to the logarithm of the ambient pressure and port diameter. This relation is applicable despite the flow condition. Furthermore, we calculated velocity gradient at the fuel surface to reveal the determining factor of the blowoff limit in laminar flow. Consequently, velocity gradient, which is considered to dominate flow separation in laminar flow, would not be constant. This is because the velocity gradient at the fuel surface could not be evaluated by only the assumption of Hagen–Poiseuille flow but other parameters, such as vaporized fuel gas and natural convection by buoyancy should be included.     

固体火箭冲压发动机燃气发生器及燃气流量调节阀建模及仿真

研究了一种气动式的燃气流量调节阀,并建立了固体火箭冲压发动机燃气发生器和气动式燃气流量调节阀的数学模型及仿真模型,对燃气流量调节阀仿真模型进行了试验验证,动态误差和稳态误差都在5%以内。通过仿真获得了燃气发生器和燃气调节阀的动态响应特性。仿真结果表明,燃气调节系统开环响应速度较慢,并具有很强的非线性。     

固体火箭羽焰的辐射特性及其温度测量技术述评

叙述了固体火箭羽焰的辐射特性,简要地介绍了热电偶法、等离子体法、光纤测温法、谱线反转法、发射吸收法、喇曼光谱法、微波衰减法、红外测温法和多光谱测温法的原理和应用。评述了这些火焰测温方法在羽焰测温上的适应性,并指出多光谱测温技术是羽焰测温的发展趋势之一。     

有限元分析在大推力火箭动力系统试验台承力架结构优化中的应用

采用通用有限元软件ANSYS建立了某火箭动力系统试验台承力架有限元模型,分析了该承力架在试验状态和试验准备状态下的应力分布,根据应力分析结果对承力梁的结构和布局作了相应优化,使结构强度满足工作要求。同时对局部结构——承力环支腿进行了应力分析和优化。最后分析了承力架的自身模态,其轴向一阶振型在试验件轴向一阶振型范围内,需...     

基于减小初始扰动的弹管间隙优化设计方法

针对火箭/发射装置系统,用牛顿-欧拉法建立了火箭和发射管的动力学方程组,基于MATLAB平台编写了方程组求解程序,在此基础上分析了弹管间隙对火箭初始扰动的影响,并利用二次回归模型求出了弹管间隙的最优解。计算结果表明,初始扰动角和角速度是弹管间隙的二次函数,而最优弹管间隙为该二次函数构成的齐次方程的解。该方法能为火箭发射系统的设计提供参考。     

探空火箭有效载荷集成测试软件系统的设计与实现

为适应国内新一代探空火箭载荷系统的各类测试需求,集成测试软件系统综合采用了组播和USB等技术;软件算法上实现了相位解模糊、RS译码等功能,解决了载荷数据的校验问题,提高了系统的可靠性.“子午工程”首枚探空火箭成功发射的经验表明,该软件系统的设计满足探空火箭有效载荷的集成测试需求,具有较好的通用性及可扩展性,有效降低了测试系统的硬件成本.     

中国台湾反舰导弹评析

现代反舰导弹正向系列化、远射程、高速度、隐形化方向发展，并已成为对海作战的重要武器。中国台湾历来重视海军舰艇导弹化的进程，从 20世纪 70年代起就开始引进和自行研制反舰导弹，近年来更是加快了改进与升级的速度。经过 30余年的苦心经营，通过外购、仿制和自研等途径，台湾反舰导弹的数量和质量都达到了一个较高的水平。 种类与性能 　　20世纪 70年代末，台湾仿造以色列的“迦伯列”反舰导弹，研制成功“雄风” 1型近程反舰导弹； 90年代初自制成功“雄风” 2型中程反舰导弹； 1997年，又从美国购入 AGM－ 84“捕鲸叉”反舰导弹…     

大陆与台湾地区民航空管的区别

本资料汇编是在多位台湾爱国飞行员和航管员的大力支持下,前后历时四年编写完成的。目前台湾航空公司已经开始飞越祖国大陆,在不久的将来海峡两岸有望直接通航,希望该资料汇编能为各相关业务部门提供借鉴,更有力地保障飞行安全。由于受条件限制,难免有所纰漏,希望指正。     

Cell-to-cell interactions in changed gravity: ground-based and flight experiments

Cell-to-cell interactions play an important role in all physiological processes and are mediated by humoral and mechanical factors. Mechanosensitive cells (e.g., osteocytes, chondrocytes, and fibroblasts) can be studied ex vivo to understand the effects of an altered gravity environment. In particular, cultured endothelial cells (EC) are very sensitive to a broad spectrum of mechanical and biochemical stimuli. Earlier, we demonstrated that clinorotation leads to cytoskeletal remodeling in cultured ECs. Long-term gravity vector changes also modulate the expression of surface adhesion molecules (ICAM-1, E-selectin, VCAM-1) on cultured ECs. To study the interactions of geterological cells, we cocultured endothelial monolayers and human lymphocytes, immune cells and myeloleucemic (K-560) cells. It was found that, although clinorotation did not alter the basal adhesion level of non-activated immune cells on endothelial monolayers, the adhesion of PMA-activated lymphocytes was increased. During flight experiments onboard the Russian segment of the International Space Station, we measured the cytotoxic activity of natural killer (NK) cells incubated with labeled target cells. It was found that immune cells in microgravity retained their ability to contact, recognize, and destroy oncogenic cells in vitro. Together, our data concerning the effects of simulated and real microgravity suggest that, despite changes in the cytoskeleton, cell motility, and expression of adhesion molecules, cell-cell interactions are not compromised, thus preserving the critical physiological functions of immune and endothelial cells.     

Recent experiments in laser supported absorption waves

Recent experimental studies with laser supported absorption waves, arising from intense laser radiation incident upon various surface materials, are discussed. The propagation characteristics of both subsonic (laser supported combustion), intensity about 10⁵ W/cm², and supersonic (laser supported detonation), intensity greater than 10⁶ W/cm², waves are described, including the dependence of wave speed on laser intensity, beam diameter, gas density and laser wave length. Measurements of the plasma properties in such waves are described, and the analysis of these data allows conclusions identifying the dominant transport mechanism in such waves. It is also concluded that in the LSC (subsonic) case, radial flow ahead of and within the wave are dominant features of the wave structure. The equipment and laser facilities used in the experiments are also discussed.     

Numerical experiments for supersonic and hypersonic flows

This paper contains the results of numerical experiments carried out by means of a modified non-stationary “large particle” method developed for the investigation of properties of both steady and non-steady flows associated with complicated gasdynamic problems. In the solution obtained by numerical analysis one may observe the formation of shock waves, local supersonic zones, separation regions with recirculation, and similar effects. Such phenomena are all of significance to a great number of practical problems.     

台湾反导弹防御系统的发展

台湾的天弓导弹垂直发射装置台湾的地面防空早在50年代中期就开始筹划,在美国的帮助下,经过40多年的发展,已建成了较为完善的地面防空体系,在整体上形成了环岛布置的态势,但是不具备对抗弹道导弹攻击的能力。随着战术弹道导弹的扩散,装备战术弹道导弹的国家越来越多,使台?..     

Analysis and experiments for delay compensation in attitude control of flexible spacecraft

Space vehicles are often characterized by highly flexible appendages, with low natural frequencies which can generate coupling phenomena during orbital maneuvering. The stability and delay margins of the controlled system are deeply affected by the presence of bodies with different elastic properties, assembled to form a complex multibody system. As a consequence, unstable behavior can arise. In this paper the problem is first faced from a numerical point of view, developing accurate multibody mathematical models, as well as relevant navigation and control algorithms. One of the main causes of instability is identified with the unavoidable presence of time delays in the GNC loop. A strategy to compensate for these delays is elaborated and tested using the simulation tool, and finally validated by means of a free floating platform, replicating the flexible spacecraft attitude dynamics (single axis rotation). The platform is equipped with thrusters commanded according to the on–off modulation of the Linear Quadratic Regulator (LQR) control law. The LQR is based on the estimate of the full state vector, i.e. including both rigid – attitude – and elastic variables, that is possible thanks to the on line measurement of the flexible displacements, realized by processing the images acquired by a dedicated camera. The accurate mathematical model of the system and the rigid and elastic measurements enable a prediction of the state, so that the control is evaluated taking the predicted state relevant to a delayed time into account. Both the simulations and the experimental campaign demonstrate that by compensating in this way the time delay, the instability is eliminated, and the maneuver is performed accurately.     

Compact high-voltage accelerators of charged particles in space experiments

Some general problems of design and application of compact devices for the generation of pulse electric fields at a megavolt range in space experiments are discussed. The prospect of various applications of powerful electron beams for active diagnostics of upper layers of atmosphere, radiation belts and the earth's magnetic field is also reviewed. The proposed development of powerful impulsive devices is dictated by limitations of energy resources in spacecraft together with a need to get a good signal-to-noise ratio for reliable data recording. Compact devices which directly transform electric energy of a low-voltage source (solar batteries, chemical elements, nuclear reactor, etc.), into the energy of a megavolt charge particle beam of high impulsive power appear as reliable means for satisfying these requirements. In this paper, the basic practical schemes of energy transformation procedures are considered and the optimal operation parameters of high-voltage storage and transformer systems are discussed. Proper application of combined high-voltage insulation techniques result in the development of experimental models of heavy-current electron beam accelerators capable of generating beams of 300–500 kV, 3–5 kA, with a pulse duration of 15 × 10⁻⁹ sec at a frequency of 10 Hz. Typical applications of electron beam accelerators including the generator of electron-beam-controlled discharge laser beams are also described.     

NASA's in-space technology experiments program: Status and plans

Experience with the Shuttle and free-flying satellites as technology test beds has shown the feasibility and desirability of using space assets as facilities for technology development. Thus, by the time the space station era arrives, technologists will be ready for an accessible engineering facility in space. Along with the scientific and commercial space development communities, the technology development community has been participating in defining requirements for this in-space facility. As the 21st century is approached, it is expected that many flights to the Space Station Freedom will carry one or more RT&E experiments. The experiments are likely to utilize both the pressurized volume, and the external payload attachment facilities. Based on the success of instrumenting the Shuttle itself to obtain ascent and descent aerothermodynamic data a unique, but extremely important, class of experiments will use the space station itself as an experimental vehicle.     

Function,geometry and spatial prepositions: Three experiments

In this paper the results of three experiments are reported whichaddress the issue of the relative extent to which functionalrelations versus geometric relations affect spatial language. Theexperiments examine the role of a discourse context on the useand rating of the preposition in to describe a visual scenewhere the constraint of spatial containment between figure(object located) and ground (reference object) does not hold. Allthree experiments demonstrate that in is used more andrated to be significantly more appropriate in a functionalcontext than in a no context condition. The implications of thesestudies for spatial language and spatial representation arediscussed.