The warp engine designed by Henry Archer that let Earth ships reach warp 5 for the first time, powering Enterprise NX-01 on humanity's first deep-space mission in 2151.
The warp five engine is the propulsion system at the heart of Star Trek: Enterprise. Henry Archer, father of Jonathan Archer, designed it at the Warp Five Complex, building on the work of Zefram Cochrane. He did not live to see it fly, and his son blamed Vulcan caution for the decades of delay.
The flashback episode First Flight shows the NX test programme of the 2140s, in which Archer and A.G. Robinson prove that the engine design is sound. The finished engine is installed in Enterprise NX-01, launched in Broken Bow in 2151.
Enterprise first reaches warp 5 in Fallen Hero in 2152 while outrunning Mazarite ships. Chief engineer Trip Tucker maintains the engine through the series, and the same design powers the second ship, Columbia NX-02.