Star Trek: Deep Space Nine (sometimes abbreviated to DS9) is a science fiction television series set in the Star Trek universe in the Milky Way galaxy, in the years 2369–2375. In contrast to other Star Trek TV shows, it takes place on a space station instead of a starship, so as not to have two series with starships in the same time period. (The starship USS Defiant was introduced in season 3, but the station remained the show's primary setting.)