NGC 400 was a star that, as of stardate 3475.3 (2267) was the furthest into the Milky Way Galaxy that had been explored by the United Federation of Planets, the Klingon Empire, or the Romulan Confederation. According to Commander Spock, "So far as we are concerned, there is nothing beyond." The USS Enterprise had to travel to this location before opening sealed orders sending the ship on to NGC 434. (TOS novel: Mission to Horatius)