Aerospace is the human effort in science, engineering, and business to fly in the atmosphere of Earth (aeronautics) and surrounding space (astronautics). Aerospace organizations research, design, manufacture, operate, or maintain aircraft or spacecraft. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace is the human effort in science, engineering, and business to fly in the atmosphere of Earth (aeronautics) and surrounding space (astronautics). Aerospace organizations research, design, manufacture, operate, or maintain aircraft or spacecraft. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace is not the same as airspace, which is the physical air space directly above a location on the ground. The beginning of space and the ending of the air is considered as 100 km above the ground according to the physical explanation that the air pressure is too low for a lifting body to generate meaningful lift force without exceeding orbital velocity. In most industrial countries, the aerospace industry is a cooperation of public and private industries. For example, several countries have a civilian space program funded by the government through tax collection, such as National Aeronautics and Space Administration in the United States, European Space Agency in Europe, the Canadian Space Agency in Canada, Indian Space Research Organisation in India, Japanese Aeronautics Exploration Agency in Japan, RKA in Russia, China National Space Administration in China, SUPARCO in Pakistan, Iranian Space Agency in Iran, and Korea Aerospace Research Institute (KARI) in South Korea. Along with these public space programs, many companies produce technical tools and components such as spaceships and satellites. Some known companies involved in space programs include Boeing, Cobham, Airbus, SpaceX, Lockheed Martin, United Technologies, MacDonald Dettwiler and Northrop Grumman. These companies are also involved in other areas of aerospace such as the construction of aircraft. Modern aerospace began with Engineer George Cayley in 1799. Cayley proposed an aircraft with a 'fixed wing and a horizontal and vertical tail,' defining characteristics of the modern airplane. The 19th century saw the creation of the Aeronautical Society of Great Britain (1866), the American Rocketry Society, and the Institute of Aeronautical Sciences, all of which made aeronautics a more serious scientific discipline. Airmen like Otto Lilienthal, who introduced cambered airfoils in 1891, used gliders to analyze aerodynamic forces. The Wright brothers were interested in Lilienthal's work and read several of his publications. They also found inspiration in Octave Chanute, an airman and the author of Progress in Flying Machines (1894). It was the preliminary work of Cayley, Lilienthal, Chanute, and other early aerospace engineers that brought about the first powered sustained flight at Kitty Hawk, North Carolina on December 17, 1903, by the Wright brothers. War and science fiction inspired great minds like Konstantin Tsiolkovsky and Wernher von Braun to achieve flight beyond the atmosphere. The launch of Sputnik 1 in October 1957 started the Space Age, and on July 20, 1969 Apollo 11 achieved the first manned moon landing. In April 1981, the Space Shuttle Columbia launched, the start of regular manned access to orbital space. A sustained human presence in orbital space started with 'Mir' in 1986 and is continued by the 'International Space Station'. Space commercialization and space tourism are more recent features of aerospace. Aerospace manufacturing is a high-technology industry that produces 'aircraft, guided missiles, space vehicles, aircraft engines, propulsion units, and related parts'. Most of the industry is geared toward governmental work. For each original equipment manufacturer (OEM), the US government has assigned a Commercial and Government Entity (CAGE) code. These codes help to identify each manufacturer, repair facilities, and other critical aftermarket vendors in the aerospace industry.