History of space

The interface between Earth's atmosphere and space. The Kerman line is shown at an altitude of 100 km above the Earth's surface. While the layers of Earth's atmosphere are drawn to scale, objects inside it, such as the International Space Station, are not.

 Space does not begin at a fixed height above the Earth's surface. Conventionally, the Kerman Line at an altitude of 100 km (62 m) above sea level is considered the beginning of space in various space-related treaties and for recording space-related documents. [7][8] The Outer Space Treaty, which entered into force on 10 October 1967, established the framework for international outer space law. According to this treaty, the sovereignty of any state over outer space is declared impossible and all states are allowed to carry out space exploration freely. Although numerous UN resolutions have been drawn up for the peaceful use of outer space, artificial anti-satellite weapons have been tested in Earth orbit.

 Mankind first began space exploration with the advent of high-altitude balloon flight in the 20th century AD. After that the manned rocket flight and after that the manned passenger earth orbit (Earth orbit) is completed. In 1961, Yuri Gagarin of the Soviet Union became the first man to orbit the Earth from space. Space is an extremely hostile environment for exploration by flesh-and-blood humans due to vacuum and radiation. In addition, molecular gravity has a negative effect on human bodily processes, resulting in muscle wasting and osteoporosis. Apart from these health and environmental issues, the economic cost of sending anything, including humans, into space is also prohibitive. Human spaceflight is limited to low Earth orbit and the Moon because it is too expensive to enter space. But in contrast, unmanned spacecraft have been able to reach all the planets in the solar system.