In 2063, the Phoenix reached warp threshold and broke the warp barrier. (Star Trek: First Contact) In 2143, the NX-class prototypes broke the warp barrier, known as the warp 2 barrier. (ENT: "First Flight") The time barrier was a warp barrier broken some time between 2236 and 2254. (TOS: "The Cage" ) The USS Enterprise was a starship with a warp drive that had surpassed this barrier. Multiple production sources, including an unseen display screen intended for use in "In A Mirror, Darkly, Part II", the Star Trek Encyclopedia, and The Making of Star Trek, give the Enterprise launch date as 2245.