The USS Lexington (NCC-14427) was an Excelsior-class Starfleet starship in service during the 24th century. (Star Trek: Encyclopedia) The Lexington transferred medical supplies to the Enterprise-D for delivery to the Taranko colony in 2370. (TNG: "Thine Own Self") The Star Trek: Encyclopedia appears to contradict the Star Trek: Deep Space Nine episode "Explorers", which has a Nebula-class Lexington in service by 2369.