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The Enterprise undergoing a refit

"I know engineers, they love to change things!"

Refit, retrofit, or maintenance overhaul was the processes by which a piece of technology (such as a starship or any of its components) was overhauled and re-outfitted with newer technology.


A refit was the installation of updated equipment aboard a starship. It differed from a retrofit in that the vessel's overall structure was changed during the process. A refit required some form of spacedock. (Star Trek: The Motion Picture; Star Trek V: The Final Frontier; Star Trek VI: The Undiscovered Country)

During the mid-22nd century, the Romulans modified one of their warbirds into a drone ship. (ENT: "The Aenar")

In 2260 of the alternate reality, the USS Enterprise was repaired and refitted with a new, wider impulse engine as well as new warp drive components on the fins of the nacelles for her first five-year mission. By 2263, the nacelles were replaced with slightly smaller units and the nacelle pylons were swept back away from the primary hull. (Star Trek Into Darkness; Star Trek Beyond)

The original USS Enterprise underwent a major redesign and refit beginning in 2270 which essentially turned it into a new vessel. The refit, which required eighteen months in Spacedock, involved changing or reconstructing a majority of the ship's systems, including the weapon's systems and warp drive. (Star Trek: The Motion Picture)

Following the Enterprise's battle with the USS Reliant, Montgomery Scott informed Admiral James T. Kirk that the refit time required until the ship could be taken out again would be eight weeks, but that he could do it in two. Kirk then noted Scotty's propensity to multiply his repair estimates by a factor of four, to which Scotty replied, "How else can I keep my reputation as a miracle worker?" However, Admiral Morrow stated that there would be no refit of the Enterprise, choosing instead to decommission her and reassign Mr. Scott to the USS Excelsior. (Star Trek III: The Search for Spock)

The USS Enterprise-D underwent a computer refit during its first year (TNG: "Datalore") as well as a very extensive refit after the Borg incursion in 2367. (TNG: "The Best of Both Worlds, Part II", "Family")

The USS Lakota was refitted in 2372, just before Benteen took command. The refit included upgrades to weapons beyond the norm for an Excelsior-class ship, including quantum torpedoes. (DS9: "Paradise Lost")

In 3189, the time-displaced USS Discovery received several upgrades as part of a refit to make her suitable for the era, this included detached nacelles, a modified navigational deflector, programmable matter control surfaces, and an enhanced Spore Hub Drive control system. Her registry was also changed by adding a hyphenated letter: A. (DIS: "Scavengers") The vessel was also equipped with a cloaking device. (DIS: "Su'Kal")


A retrofit was the installation of updated equipment aboard a starship. It differs from a refit in that the vessel's overall structure remained unchanged in the process – the components in question were simply swapped out. A retrofit did not always require a spacedock.

A standard part of retrofits was to switch out the bridge module of a starship design. Bridge modules might appear radically different from previous versions, while the structure of the starship might remain the same. (Star Trek: The Motion Picture; Star Trek V: The Final Frontier; Star Trek VI: The Undiscovered Country; Star Trek Generations)

The concept of replaceable bridge modules was developed to explain why the bridge of the Enterprise and USS Enterprise-A appeared completely different over the course of various films, or the USS Enterprise-D between seasons 1 and 2, and season 7 and Generations.

In late-2370, Captain Keogh asked Chief O'Brien to retrofit Deep Space 9's Danube-class runabouts with an extra complement of photon torpedoes prior to joining the USS Odyssey on a rescue mission to the Gamma Quadrant. (DS9: "The Jem'Hadar")

In early 2372, Benjamin Sisko told Kasidy Yates that Deep Space 9 was being retrofitted, although in actuality it was being upgraded with new weapons systems. (DS9: "The Way of the Warrior")

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