Basic Researches on Planetary Aerobrake Technology

这项研究的目的是建立与航空制动有关的基本技术，使行星探测器能够以相对较少的推进剂质量插入行星轨道。其直接目的是利用地球轨道卫星进行技术论证和研究以氢为主的行星大气中的气体动力学。在研究合同的最后一年，没有机会向地球轨道发射一个演示器。飞行单元的升级包括：重新编程能力，以及通过几个单元的统一减少质量。对非烟火分离装置进行了反复试验，直到验证了实施的可能性。延长线已投入环境试验。在姿态轨道控制方面，利用系绳运动建立了有效的轨道控制方法。在气体动力学方面，基于氢分子旋转弛豫、振动弛豫和化学反应的氢高超声速稀薄气体分析为在木星大气中进行气捕提供了可行性。实验中，在爆轰触发膨胀管作用下，高超声速氢流达到8km/s。将碳烧蚀器暴露在电弧加热空气中，并通过对产生气体成分的光谱分析证实了散裂的发生。为了应对强激波后的非平稳大湍流，引入LES/RANS混合模型，建立了一种新的模型公式，提高了模型精度。

The purpose of the research is to establish fundamental technologies related to Aerobrake which enables planetary explorers to be inserted into orbits around the planet with relatively small amount of propellant mass. The direct purposes are technology demonstration utilizing earth orbiting satellite and research of gas dynamics within planetary atmosphere which is dominated by hydrogen. In this last year of the research contract, an opportunity was not available to launch a demonstrator into earth orbit.The flight unit was upgraded by: inclusion of re-programming capability, and mass reduction through unification of several units. Non-pyrotechnic separation device was repeatedly tested until possibility of implementation was verified. Extension rod has been put into environmental tests. In the area of attitude-orbit control, an effective orbit control was established by utilizing tether motion.In the area of gas dynamics, hydrogen hypersonic rarefied gas analysis with hydrogen molecule rotation relaxation, vibration relaxation and chemical reactions provided feasibility of aerocapture in Jovian atmosphere. In the experiment, hypersonic hydrogen flow attained 8km/s with detonation invoked expansion tube. Carbon ablator was exposed to arc heated air and occurrence of spallation was confirmed through spectroscopic analysis of resultant gas components. To cope with a non-stationary large turbulence behind a strong shock wave, a novel model formulation was established introducing LES/RANS hybrid model which enhances precision.