The USS Atlantis (NCC-21081) was a Emperor-class Starfleet science vessel commissioned in 2381, under the command of Captain Percival Day. (Star Trek: Pioneer) The ship was named after the lost city of Atlantis, from Ancient Greece's mythology. In 2382, the Atlantis was assigned to assist the archeological team investigating the ruins of Andres Rae. ("The Ruins") In 2383, the Atlantis assisted the USS Pioneer in the search for the mythical planet of Yoth. ("The Forgotten Planet")