The possibility of building returnable satellites is largely determined by the success in the development of new materials of space technology, capable of maintaining their strength during heating, not interacting with the oxygen of the upper atmosphere, and therefore not breaking down from corrosion, to protect the crew and instruments from space and X-ray radiation. To study the properties of new materials, it is necessary to comprehensively test them in conditions close to space. And for this you have to create "space" on Earth.