In the mirror universe, the Utopia Planitia Fleet Yards was a ship construction and maintenance yard operated by the Terran Empire during the 23rd century. Its surface facilities were based in the Utopia Planitia area on Mars in the Sol System. In 2264, Commander James T. Kirk departed the Utopia Planitia Yards on his way to the Tantalus colony. (TOS - Mirror Universe short story: "The Greater Good")