Launched in 2154, Columbia was the sister ship to Enterprise. Both were NX-class vessels, though Columbia sported many new and redesigned systems. (ENT: "The Expanse", "E²", "Home", "Affliction") By 2256, the two Crossfield-class starships USS Discovery and USS Glenn were considered sister ships. (DIS: "Context Is for Kings") The Federation Constitution-class heavy cruisers USS Enterprise and USS Constellation were sister ships during the 23rd century. (TOS: "The Doomsday Machine" )