Space technology is a comprehensive engineering technology that provides technical means and guarantee conditions for space activities. Space application refers to the use of space technology and its development of space resources in scientific research, national economy, national defense construction, culture and education and other fields of application technology. Space resources refer to all kinds of environment, energy and material resources which can be exploited and utilized for human beings outside the earth's atmosphere, and enter into space at high and far positions, high vacuum, ultra-low temperature, strong radiation, microgravity environment, solar energy and material resources of celestial bodies outside the earth.