The problems of creating and using national economic and scientific space complexes, the principles of their construction, the laws of design parameters and the design methodology are described. The results of space activities, the needs of the national economy and science, the promising possibilities of space technology and the ways of its evolution are considered. In the second edition (1st ed. 1985, under the name. "National economic and scientific space complexes"), part I deserves special attention. It sets out the essence of a new direction in mechanical engineering. The problems of creation, operation and development prospects of various space vehicles, including large-sized structures, orbital cable systems, transport centers are considered. The basics of weightlessness physics and analysis of the state and development paths of orbital production of crystals and medicobiological preparations are given. Some of these materials were included in the book "Scientific and Economy-oriented Space Systems" (translated into English by 1st ed. under the title. "National Economic and Scientific Space Complexes"), published by the Mir publishing house in 1988 for scientists. It will be useful to the creators of space complexes and specialists from various sectors of the national economy.