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1.
讨论了一种微重力火箭总体设计中减旋方案,飞行载荷,气动加热与壁温计算等几个关键问题。结合该火箭的具体特点,提出了一种简单实用的被动式减旋措施,即,安装反旋尾翼及辅助减旋机构,并分析了减旋与动稳定性的关系。对超高音速火箭的飞行载荷和气动热进行了分析计算。  相似文献   

2.
为通过弹道优化设计提升火箭发射圆轨道卫星的运载能力,同时提高火箭对不同发射任务的适应性,需要火箭末级具备长时间在轨滑行能力。对氢氧末级火箭而言,延长在轨滑行时间需要解决的一个重要问题是液氢贮箱压力、推进剂温度的预示和控制。结合微重力下贮箱内低温推进剂力热耦合运动特征,给出了低温火箭在轨滑行过程中贮箱压力控制的设计流程和计算方法,并通过计算分析获得了整个滑行阶段液氢蒸发量、补压气瓶需求量等关键设计参数,为工程研制提供参考。  相似文献   

3.
Space flight is normally associated with exposure to reduced acceleration (microgravity) and the medical consequences are well described. However, it inevitably also requires periods of increased acceleration during ascent and descent. These periods, although short in comparison to the length of the flight, are classified as long-duration by physiologists. The biological consequences for man [text incomplete]  相似文献   

4.
Fluid transport in capillary systems under microgravity   总被引:1,自引:0,他引:1  
The wetting kinetics of model tubes of different geometries has been investigated experimentally and theoretically under conditions of simulated zero-gravity and microgravity. Numerical calculations of meniscus configurations and the rise of the menisci in tubes of different shape are compared with photographic pictures obtained from sounding rocket experiments (TEXUS-Programme). It is demonstrated that menisci under microgravity conditions are essentially different from those of simulated zero-g-experiments. These results, together with observed streamline patterns, yield valuable information with respect to the hydrodynamic deformation of phase interfaces and dynamic contact angles.  相似文献   

5.
TY-3微重力火箭总长 6 0 0 0 mm,起飞质量 1 1 0 0 kg,有效载荷 5 0 kg,最大飞行高度 2 2 0 km,能提供 1 0 - 4 g约 36 0 s时间的微重力试验条件 ,该火箭已于 2 0 0 0年 1 0月飞行试验成功 ,而且一种更先进的微重力火箭系统正在设计中。  相似文献   

6.
7.
Aim of this investigation is the study of molecular modifications occurring in differentiated mammalian cells exposed to gravitational changes. The test system chosen is a well characterized clone of differentiated, normal thyroid follicular cells (FRTL5) in long-term culture. As a follow-up to our recent experiment performed during the MASER-7 sounding rocket mission, flown for European Space Agency by Swedish Space Corporation in May 1996, we evaluated FRTL5 cells responses to Thyroid Stimulating Hormone dependent cAMP production under acute hypogravity conditions obtained in a fast rotating clinostat. Following this approach, we evaluated the FRTL5 cells response to TSH under microgravity conditions in order to optimize experimental tools and strategies in preparation to, and in between real flight missions.  相似文献   

8.
Uri JJ  Lebedev ON 《Acta Astronautica》2001,48(5-12):845-851
The Phase 1 research program was unprecedented in its scope and ambitious in its objectives. The National Aeronautics and Space Administration committed to conducting a multidisciplinary long-duration research program on a platform whose capabilities were not well known, not to mention belonging to another country. For the United States, it provided the first opportunity to conduct research in a long-duration space flight environment since the Skylab program in the 1970's. Multiple technical as well as cultural challenges were successfully overcome through the dedicated efforts of a relatively small cadre of individuals. The program developed processes to successfully plan, train for and execute research in a long-duration environment, with significant differences identified from short-duration space flight science operations. Between August 1994 and June 1998, thousands of kilograms of research hardware was prepared and launched to Mir, and thousands of kilograms of hardware and data products were returned to Earth. More than 150 Principal Investigators from eight countries were involved in the program in seven major research disciplines: Advanced Technology; Earth Sciences; Fundamental Biology; Human Life Sciences; International Space Station Risk Mitigation; Microgravity; and Space Sciences. Approximately 75 long-duration investigations were completed on Mir, with additional investigations performed on the Shuttle flights that docked with Mir. The flight phase included the participation of seven US astronauts and 20 Russian cosmonauts. The successful completion of the Phase 1 research program not only resulted in high quality science return but also in numerous lessons learned to make the ISS experience more productive. The cooperation developed during the program was instrumental in its success.  相似文献   

9.
火箭弹概念设计的多学科优化设计方法   总被引:2,自引:1,他引:1  
为了在火箭弹概念设计阶段就可综合考虑质量、气动、动力及弹道等诸多学科的影响和耦合作用,引入了多学科优化设计方法。对该方法应用中的问题定义、基本流程、总体方案作了详细说明,对涉及的一些难点和关键点进行了分析,并给出了可行的解决方案。通过算例验证了该方法的可行性和有效性,与原型弹相比,单级推力方案的有效载荷比更高、最大马赫数更小、发动机工作时间更短;在射程基本不变的情况下,双级推力方案比单级推力方案的最大马赫数更小、火箭弹总的飞行时间更短,有效载荷比大幅降低。最后,讨论了包括密集度问题在内的进一步研究方向。  相似文献   

10.
提出了探空火箭动力系统设计参数优化计算方法.综合考虑了动力系统与火箭外弹道之间的关系.在给定有效载荷、最高射高的条件下,选取动力系统的设计参数使火箭的起飞质量最小.选用了增广拉格朗日法约束优化技术和牛顿迭代法求解数学模型.计算结果表明,该计算方法是合理的.  相似文献   

11.
The suborbital flight is a kind of flight, which reaches the space and then comes back to ground without completing one orbital revolution. The atmospheric thermosphere extends from 85 km to 600 km in altitude. Therefore, the suborbital and low-thermospheric experiments to be performed at altitude below 300 km can be combined using the sounding rocket. These experiments include rocket staging, fairing separation, ultrasonic flight, reentry, aerobrake and recovery test, ultraviolet and ionization observations, ozone measurement, etc. The advent of Taiwan's sub-orbital and thermospheric experiments project can be traced back to 1997. This is the year Taiwan's National Space Organization (NSPO) was assigned to be responsible for procuring the sounding rocket for applications in science experiments and space technology research effort. From 1997 to 2010, 8 launches have been completed including one experimental hybrid rocket. All onboard instruments and sensors for sub-orbital and low-thermospheric experiments are developed and integrated by the domestic universities. More launches have been planned in the future. Opportunities for international cooperation in developing new instruments and payloads for future experiments will be possible.  相似文献   

12.
The aim of this work was to analyze the possible alteration of thyrotropin (TSH) receptors in microgravity, which could explain the absence of thyroid cell proliferation in the space environment. Several forms of the TSH receptor are localized on the plasma membrane associated with caveolae and lipid rafts. The TSH regulates the fluidity of the cell membrane and the presence of its receptors in microdomains that are rich in sphingomyelin and cholesterol. TSH also stimulates cyclic adenosine monophosphate (cAMP) accumulation and cell proliferation. Reported here are the results of an experiment in which the FRTL-5 thyroid cell line was exposed to microgravity during the Texus-44 mission (launched February 7, 2008, from Kiruna, Sweden). When the parabolic flight brought the sounding rocket to an altitude of 264?km, the culture media were injected with or without TSH in the different samples, and weightlessness prevailed on board for 6 minutes and 19 seconds. Control experiments were performed, in parallel, in an onboard 1g centrifuge and on the ground in Kiruna laboratory. Cell morphology and function were analyzed. Results show that in microgravity conditions the cells do not respond to TSH treatment and present an irregular shape with condensed chromatin, a modification of the cell membrane with shedding of the TSH receptor in the culture medium, and an increase of sphingomyelin-synthase and Bax proteins. It is possible that real microgravity induces a rearrangement of specific sections of the cell membrane, which act as platforms for molecular receptors, thus influencing thyroid cell function in astronauts during space missions.  相似文献   

13.
The data of inclined sounding obtained on July 5, 1999 after explosion of the Proton carrier launcher in the upper atmosphere are discussed. A comparative analysis is performed of the detected disturbances with disturbances recorded during explosion of the Soyuz rocket in the middle atmosphere and with disturbances typical for the standard mode of the rocket flight.  相似文献   

14.
A floating zone experiment with a coated surface was performed in a sounding rocket. Analysis of the segregation showed that elimination of free surfaces decreased the convection in the liquid zone. Analysis of radial segregation during floating zone crystal growth under different experimental conditions demonstrated high sensitivity to interface shape and to convection. Under conditions of very weak convection, microgravity and coated surfaces, dopant concentration fields giving severe radial segregation were built up.  相似文献   

15.
中国航天固体火箭技术的发展   总被引:5,自引:0,他引:5  
叙述了20世纪50年代以来中国航天固体火箭推进技术的发展历程,介绍了9种最具代表性的固体火箭发动机的技术特征、研制过程、地面试验和飞行情况,这些发动机分别应用于中国的探空火箭、运载火箭上面级和应用卫星变轨系统。文中还简要地评述了中国固体推进各单项技术的发展水平。  相似文献   

16.
以现有空中发射运载火箭"飞马座"(Pegasus)为研究对象,研究了空中发射运载火箭的弹道优化设计方法。在建立的空中发射运载火箭动力学模型的基础上,考虑空中发射火箭独特气动外形,设计发射全过程的飞行控制模型;给出了使用遗传算法(GA)筛选弹道优化问题全局最优初值,并交叉运用起作用集算法(ASM)与内点法对GA算法获得的初值二次寻优,从而获得空中发射火箭弹道的分级优化设计方法,另与"飞马座"空中发射运载火箭的弹道数据对比,验证了该分级优化方法相比传统弹道优化设计方法,适用的目标轨道范围广阔,发射位置灵活,能够更大程度挖掘空中发射运载火箭的运载能力。  相似文献   

17.
介绍了主发动机加助推器和简易控制方法实现固体火等高飞行的设计方案,助推器工作结束后,火箭达到预后飞行速度,主发动机开始工作,使火箭的推力等于其所受阻力,同时火箭产生的升力等于其重力,保证火箭可靠速飞机,火箭控制系统可保证其在某一高度上平飞。  相似文献   

18.
The X-33 program was initiated to develop a testbed for integrated RLV technologies that pave the way for a full scale development of a launch vehicle (Venture Star). Within the Nasa Future X Trailblazer program there is an Upgrade X-33 that focuses on materials and upgrades. The authors propose that the most significant gains can be realized by changing the propulsion cycle, not materials. The cycles examined are rocket cycles, with the combustion in the rocket motor. Specifically, these rocket cycles are: turbopump, topping, expander, air augmented, air augmented ram, LACE and deeply cooled. The vehicle size, volume, structural weight remain constant. The system and propellant tank weights vary with the propulsion system cycle. A reduction in dry weight, made possible by a reduced propellant tank volume, was converted into payload weight provided sufficient volume was made available by the propellant reduction. This analysis was extended to Venture Star for selected engine cycles. The results show that the X-33 test bed could carry a significant payload to LEO (10,000 Ib) and be a valuable test bed in developing a frequent flight to LEO capability. From X-33 published information the maximum speed is about 15,000 ft/sec. With a LACE rocket propulsion system Venture Star vehicle could be sized to a smaller vehicle with greater payload than the Venture Star baseline. Vehicle layout and characteristics were obtained from: http:// www.venturestar.com.  相似文献   

19.
The Long March 5(LM-5) launch vehicle is China's new generation heavy-lift rocket with the largest payload capacity,representing the highest standard of China's current launchers.It took 10 years to develop the LM-5 launch vehicle.On November 3,2016,the LM-5 carrier rocket blasted off from the Wenchang satellite launch center on Hainan Island,achieving a successful maiden flight.During the development of the LM-5 rocket,the engineering team accumulated abundant experience on developing heavy-lift cryogenic rockets and established a thorough research and development system for new generation launch vehicles,which significantly raised the ability for launcher RD.  相似文献   

20.
针对火箭飞行异常下的遥测天线继续实时跟踪难的问题,提出一种飞行异常后的实时跟踪角度的预测方法.首先介绍几种常用坐标系以及坐标系之间的转换关系,并将火箭飞行异常后的运动简化为考虑惯性速度的自由落体运动,给出自由落体速度模型和实时跟踪角度的计算方法步骤.设计仿真实验,验证方法的有效性,可以作为火箭飞行异常后遥测天线实时跟踪...  相似文献   

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