Later that year, the Lexington, under the command of Commodore Bob Wesley, rendezvoused with the USS Enterprise at Starbase 6 to inform Captain James T. Kirk that the Enterprise was to participate in the M-5 drills. Designed to test the new M-5 multitronic unit. It was in these war games that the Lexington served as the flagship of the four-ship task force (USS Lexington, USS Excalibur, USS Hood, USS Potemkin) that was opposing the Enterprise.
The simulation began with the Lexington and the Excalibur engaging the Enterprise near the planet Alpha Carinae II in an unscheduled battle to test the M-5's reaction to a surprise attack. After-action analysis, based on the quantity and quality of hits on the Lexington, indicated that the Enterprise, directed by the M-5, had been victorious.
Later, when the M-5 became unstable, the Lexington was hit multiple times by full-powered phasers from the Enterprise in the engineering section, damaging impulse engines and leaving her maneuverable only on warp drive. Fifty-three of her crew were killed.
When the Excalibur's entire crew was killed and she was left adrift by the M-5, Wesley requested and received permission to destroy the Enterprise with the remainder of his damaged ships. However, the M-5 was deactivated before this could be carried out. (TOS: "The Ultimate Computer")
|USS Ahwahnee • USS Constellation • USS Defiant • USS Eagle • USS Emden • USS Endeavour • USS Enterprise • USS Enterprise-A • USS Excalibur • USS Exeter • USS Hood • USS Intrepid • USS Korolev • USS Lexington • USS Potemkin • NCC-1700 • Unnamed|
|Mirror universe: USS Defiant • ISS Enterprise|
|Alternate reality: USS Enterprise • USS Enterprise-A • Unnamed|
Greg Jein's influential "The Case of Jonathan Doe Starship" article, published in the April 1973 issue 27 of the T-Negative fanzine, was the first work to assign the NCC-1709 registry number to this ship. In the article, Jein had made an attempt to "logically" couple the registry numbers as seen in "Court Martial" with the names listed in the reference book The Making of Star Trek. Michael Okuda took his cue from the article, and propagated the number throughout his subsequent reference work writings, most notably the Star Trek Encyclopedia. When the remastered version of the series began its release, Okuda, then visual effects producer for the project, made use of the opportunity to elevate Jein's until then conjectural ship's registry to canon.
The name of the ship had already been established by the producers at the start of second season of Star Trek: The Original Series, when they composed a definitive fourteen ship list belonging to the Constitution-class, then still referred to as "Starship-class" by them, including the Lexington. The annotations of D.C. Fontana and Producer Robert Justman on their first two memo proposals, stated that they had named the Lexington after one of the two historical US World War II aircraft carriers named Lexington, either the USS Lexington (CV-2) or the USS Lexington (CV-16). The Star Trek Encyclopedia (4th ed., vol. 1, p. 462) stated that the Lexington was named for one of these carriers, failing to specify which one. These carriers fought in the Pacific theater during this war. (The Making of Star Trek, pp. 164-165; Star Trek Encyclopedia (4th ed., vol. 1, p. 462))
According to Star Fleet Technical Manual the registry of the Lexington was NCC-1703, with NCC-1709 given to the USS Valiant. In the novel Yesterday's Son, the Lexington's registry is given as NCC-1704.
According to the reference work Ships of the Line (p. 86), the Lexington went through the same refitting process as her sister ship, the Enterprise.
The Lexington is one of four vessels (and the sole TOS-era ship) selected as a setting for the Star Trek Adventures playtest in 2016.