Astronaut is the term the US uses for a person who goes into space, cosmonaut is the Russian term. The first astronaut to fly into space was Alan Shepard, who flew the Mercury spacecraft Freedom 7 on a 15-minute suborbital flight on May 5, 1961. However, the first person to fly in space was Yuri Gagarin, who orbited the earth three times on April 12, 1961. Although this was 23 days before Shepard's flight, since Gagarin flew on Soviet spacecraft he was a cosmonaut, not an astronaut.