Astronaut An astronaut is a person who pilots a spacecraft or works in space, particularly in the space program of the United States. In Russia and the other former republics of the Soviet Union, such men and women are called cosmonauts. The cosmonaut program was a project of the Soviet Union until the country broke up in 1991. Russia then took over the program. China sent its first astronaut into space in 2003. Astronauts and cosmonauts operate spacecraft and space stations, launch and recapture satellites, and conduct scientific experiments. The word astronaut comes from Greek words that mean sailor among the stars. Cosmonaut means sailor of the universe. Astronauts in the Chinese space program are sometimes called taikonauts. Taikonaut comes from the Chinese words tai kong (outer space). Most U.S. astronauts work for the National Aeronautics and Space Administration (NASA). They live and train at the Lyndon B. Johnson Space Center in Houston. NASA launches astronauts into space aboard space shuttles. NASA selects two kinds of astronauts for space flights: pilot astronauts and mission specialist astronauts. Pilot astronauts command and pilot shuttles. Most pilot astronauts are test pilots from the United States Air Force, Navy, or Marine Corps. They are paid according to their military rank. Mission specialists work with pilots to maintain spacecraft and the equipment aboard. They also conduct experiments and launch satellites. In addition, they perform spacewalks to work outside the spacecraft. Mission specialists may be engineers, scientists, or physicians who have extensive research experience. Those who are in the armed forces are paid according to their rank. The civilians receive salaries based on an equivalent rank in the civil service system. This system includes almost all the federal government's civilian employees who are appointed rather than elected. A third kind of astronaut is called a payload specialist. This kind of astronaut carries out scientific experiments involving the payload (cargo) on the spacecraft. Most payload specialists are scientists who work for the owner of the payload. They must be approved by NASA. The term astronaut also has a meaning that is not connected with NASA activities. In the 1960's, the United States Department of Defense awarded the rating of astronaut to military and civilian pilots who flew aircraft higher than 50 miles (80 kilometers). Seven test pilots received this rating for flights in the X-15 rocket plane. Flights of the X-15 ended in 1968. Cosmonauts train at the Yuri Gagarin Russian State Scientific-Research Test Center of Cosmonauts Training, in Starry Town, also known as Star City, near Moscow. They travel into space aboard vehicles called Soyuz. Unlike space shuttles, these vehicles are not reusable. Crews lift off from the Baykonur Cosmodrome, near the Aral Sea in south-central Kazakhstan. Landings take place in remote, flat areas of Kazakhstan. A Soyuz carries two or three highly specialized cosmonauts. The commander is almost always a military jet pilot, and the flight engineer is almost always a civilian. The flight engineer is usually a member of the staff of the design bureau responsible for the craft. On about half the Soyuz flights, a third cosmonaut, usually called the cosmonaut researcher, is aboard. This person can be a non-Russian "guest cosmonaut" or a Russian physician. Cosmonauts began making guest flights aboard space shuttles in 1994, and astronauts began visiting Russia's Mir space station in 1995. Both astronauts and cosmonauts helped build, and then worked aboard, the International Space Station. In the 1990's, China began developing a spacecraft designed to carry astronauts. The craft, called the Shenzhou, resembles the Soyuz and lifts off from Jiuquan Space Launch Center in northern China. Landings take place in remote areas of Inner Mongolia. This article discusses Astronaut (Achievements in space) (Accidents in space) (Selecting the astronauts) (A look at the astronauts) (Training the astronauts) (Astronauts on the ground) (The cosmonauts).