Knowledge about space

Knowledge about space:

The space environment is very different from the earth's environment. There is no air, no gravity, and full of dangerous space radiation. The universe beyond the earth's atmosphere, the entire space beyond the atmospheric space. Physicists divide the atmosphere into five layers: troposphere, stratosphere, mesosphere, thermosphere and outer atmosphere. Space refers to the cosmic space beyond the earth's atmosphere. The atmosphere is divided into the troposphere (from sea level to 9 kilometers), stratosphere (9-45 kilometers), mesosphere (45-80 kilometers), and thermosphere (80-400 kilometers). kilometers) and the outer atmosphere (above 400 kilometers). About 3/4 of the atmosphere above the earth is in the troposphere, and 97% is below the stratosphere. The outer edge of the stratosphere is the highest limit for aircraft to rely on air support for flight.

A space station, also known as a "space station", "orbital station" or "space station", is a manned spacecraft that can allow multiple astronauts to cruise, work and live for a long time. During the operation of the space station, the replacement of astronauts and the replenishment of supplies and equipment can be transported by manned spacecraft or space shuttles, and supplies and equipment can also be transported by unmanned spacecraft.