太空天梯网的稳定性分析与应用构想

Stability Analysis and Application Conception of Space Elevator Network

太空天梯技术是实现低成本、高效、安全航天运输的一种重要途径.传统的地球天梯和月球天梯对材料强度的要求远超现有技术水平,工程实现难度很大.而土星卫星普遍质量较小,建设土星卫星太空天梯可以有效克服现有材料技术瓶颈并极大促进土星系探索和开发利用.首先,以土卫二为例,建立了“刚性杆-珠点”天梯模型,推导出拉格朗日动力学方程.在此基础上,完成了系统的稳定性分析,利用线性稳定性理论以及拉格朗日定理分析了不同建模精度以及空间站质量下系统的稳定条件,并将计算结果推广至土星系其他卫星.之后,提出了土星系太空天梯网构想,并初步设计了能够实现在任意两颗卫星之间无工质转移的天梯网构型.最后分析了天梯网的效能和建设可行性.计算结果表明,设计的天梯网中所有天梯均能够在平衡位置保持稳定,且部分天梯能够采用现有复合材料完成建造.相比传统轨道机动方法可节省数千米每秒的速度增量,具有巨大的潜在应用价值.提出的方法和得到的结论可以为天梯网的进一步设计提供支撑.

Space elevator technology is the key to realizing low-cost,efficient and safe space transportation.The traditional earth elevator and lunar elevator require material strength far beyond the existing technical level,and it is very difficult to realize the project.Saturn's moons are generally small in mass.The construction of the Saturn's moon space elevator can overcome the technical bottleneck of existing materials and greatly promote the exploration,development and utilization of the Saturn system.First,taking Enceladus as an example,the"rigid rod-bead point"model of the ladder is established,and the Lagrangian dynamic equation is derived.On this basis,the stability analysis of the system is completed.The linear stability theory and Lagrange’s theorem are used to analyze the stability characteristics of the system under different discrete precisions and the mass of the space station,and the calculation results are extended to other satellites of the Saturn galaxy.After that,the concept of the Saturn space elevator network is proposed,and the elevator network configuration which can realize no working medium transfer between any moons is preliminarily designed.Finally,the efficiency and construction feasibility of the elevator network are analyzed.The calculation results show that all the elevators in the designed elevator network can remain stable at the equilibrium position,and some of the ladders can be constructed using existing composite materials.Compared with the traditional orbital maneuvering method,the ladder network can save the speed increment of several kilometers per second,and has huge potential application value.The method proposed in this paper and the conclusions obtained can provide support for the further design of the elevator network.