<P> An astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft . Although generally reserved for professional space travelers, the terms are sometimes applied to anyone who travels into space, including scientists, politicians, journalists, and tourists . </P> <P> Until 2002, astronauts were sponsored and trained exclusively by governments, either by the military or by civilian space agencies . With the suborbital flight of the privately funded SpaceShipOne in 2004, a new category of astronaut was created: the commercial astronaut . </P>

A person who travels in space is called