摘要
INTRODUCTION With the development of science and technology, mankind's space activities have greatly promoted social progress and produced profound and far-reaching effects.Space technology has turned out to be one field of high technology that exerts the most profound influence on modern society.The
INTRODUCTION
With the development of science and technology, mankind＇s space activities have greatly promoted social progress and produced profound and far-reaching effects. Space technology has turned out to be one field of high technology that exerts the most profound influence on modern society. The continuous development and applications of space technology has become an important endeavor in the modernization drive of countries all over the world. The first step of utilization and exploration of space is access to space, which is the foundation of all the space activities. Up to now, the launch vehicle is the most important approach to enter space.
