Excelsior class
The Excelsior-class was a type of Federation starship used by Starfleet from the late 23rd century through the early 25th century. It was the backbone of Starfleet for over a century, making it one of the longest serving starship designs, and one of the most recognizable ships in the fleet.

 History 
The Excelsior-class was initially constructed during the early 2280s at Starfleet's San Francisco Fleet Yards orbiting Earth. ( and  dedication plaque)

Starfleet had high hopes for the first ship of this class, the prototype , which was equipped with transwarp drive, and was regarded as that century's "Great Experiment." () 
 See''': Trial runs for more concise details of the USS Excelsiors early history.

Despite the failure of the "Great Experiment," Starfleet forged ahead with employing the Excelsior design. After remaining in the Earth Spacedock until at least 2287, the prototype Excelsior was subsequently recommissioned for active service by 2290. (, , ) 

In 2293, the fate of the Excelsior design was sealed when Starfleet passed on the name of a legacy. The launch of the  opened the door for the Excelsior-class to become one of the most widely used designs in all of Starfleet, lasting well into the late 24th century. (; ;  – )

Once fully integrated into the fleet, the Excelsiors sister ships were used for a variety of mission profiles, ranging from deep space exploration and terraforming missions, to patrol duty, to courier and transport runs. (; ; , etc.) The Excelsior-class was also frequently used by the Starfleet flag officers for use as a personal flagship. ()

The Excelsior-class was present in several major Federation engagements, including the Borg invasion of 2366-2367, where it participated at the Battle of Wolf 359, as well as the engagement against the Borg sphere that entered the Sol system in 2378. (; ) They were also present in numerous Dominion War battles, seeing action during Operation Return, the First and Second Battles of Chin'toka, and the Battle of Cardassia. Many Excelsior-class vessels were stationed on the front lines near Deep Space 9 during the war. (, etc.)

By 2401, a numbered successor class, the , was in service. ()

Details of this class would be retained well into the 31st century, when Captain Jonathan Archer and Lieutenant Malcolm Reed viewed schematics on the class in the 22nd century while accessing the database belonging to temporal agent . ()

 Technical data 
 Physical arrangement 

The Excelsior-class featured the saucer section-engineering section-warp nacelle layout common to most Starfleet vessels. However, it featured a more streamlined design than was seen in previous classes.

Design features of the primary hull included a docking port located on the port side of the hull. ()

 Design upgrades 
Following its initial, and somewhat unsuccessful origins, the Excelsior underwent a minor refit, which included a new bridge module, in addition to a significant modification to the aft portion of the saucer section, surrounding the impulse drive, and a modification to the cargo bay on the aft ventral portion of the ship. This configuration would remain the standard for the Excelsior-class throughout its service. () 

In less than a decade, the Excelsior design underwent a second, more significant overhaul, as introduced with the launch of the . While remaining true to the original design, this new configuration added several modifications to the basic hull, including the addition of a second pair of impulse engines, an expanded scoop surrounding the deflector dish, and the addition and removal of a number of fins located on the saucer and nacelles. (; ) 

As this class aged, Starfleet continued to incorporate the latest technology, through continued upgrades, refits and repairs, well into the 2360s and 2370s. In 2364, the  underwent significant repairs at Starbase 74, while in 2367 the  underwent a major system upgrade at Starbase 174. (, etc.)

 Tactical systems 
The original Excelsior design was outfitted with type 8 phaser emitters in five dual phaser bank emplacements on the forward saucer section, and one dual emplacement on the aft of the saucer. Phaser banks were also positioned laterally, located port and starboard, near the point that the primary and secondary hulls meet, as well as one emplacement located between the nacelles. (;  production art; , etc.)

In addition, the Excelsior was equipped with several photon torpedo launchers. The two primary launchers were located in the forward section, on both sides of the deflector dish seen as two dark colored ports ahead of the starfleet hull banners. The upper forward launchers were located on the neck section, also allowing ship access for cargo management units. Aft launchers were located above the main shuttlebay. ( production art) In addition, the shields were stronger than the  refit, capable of withstanding a direct photon torpedo strike without suffering any visible damage to the outer hull. ()

With the impending threat of the Dominion against the Federation, Starfleet began to experiment with performing a refit on the Excelsior-class  in 2372. Upgrades included improved phaser emplacements, quantum torpedoes, and other improvements to make the it competitive with newer ship designs such as the . ()

 Propulsion systems 

Initially the Excelsior was designed under a radically new principle in propulsion, the transwarp drive. While an awe-inspiring concept to some, it was the traditional engineers who remained skeptical of this new form of warp drive. () Following this failure, the Excelsior spent the next two years in spacedock before being fitted with a traditional warp drive. (; ; )

By the early 24th century, Excelsior-class vessels were normally equipped with dilithium recompositing and recrystallization technology. The theta-matrix compositor of the time, which later became outdated, was upgraded by the time the  was introduced. This new recrystallization process was ten times more efficient than that of the Excelsior-class. ()

The Excelsior-class also used micro-power relays in its warp core matrix compositor. ()

 Interior design 
 See''': Excelsior-class decks, for deck configuration.

 Main bridge 

Located on top of the primary hull, the Excelsiors main bridge directly supervised all primary mission operations and coordinated all departmental activities. Due to the age and variety of configurations of the Excelsior-class, bridge configurations varied from ship to ship.

Against the aft wall of many Excelsior bridges was the large engineering master systems display monitor, showing a cutaway of the ship and status information. This was not originally part of the USS Excelsior configuration but added later, a feature shared with sister ship USS Enterprise-B. (; ; ; )

At least one Excelsior-class starship, the , had a holo-communicator installed in its main bridge in 2373. Upon first use of the technology, Malinche Captain  described to Captain Benjamin Sisko, who was on the transmitting end on board the , "you appear to be sitting on my bridge. It may take me a while to get used to this." ()

 Ready room 
The captain's ready room was located adjacent to the bridge, and contained a desk and chair, along with a personal viewer, and was backed by several LCARS interfaces and an MSD. (; )

Ensign Nog of Deep Space 9 once explained to Chief O'Brien how Al Lorenzo liked to sneak into famous starship captain's offices and take holophotos of himself sitting behind their desks. Included in Lorenzo's collection was a holophoto of himself sitting behind Captain DeSoto's desk on board the Hood. ()

 Deflector room 

The deflector room, located on Deck 15, Section 21-alpha, was positioned directly behind the Excelsiors deflector dish. It was a small control room that could be accessed by a series of catwalks and ladders. The deflector room housed several consoles, in addition to the ship's deflector relays. ()

 Shuttle and cargo bays 

The Excelsior-class contained several cargo bays, including one located in the aft dorsal section of the secondary hull as well as several bays located along the ventral section of the secondary hull. ( production art) The main shuttlebay was located in the stern by the landing bay doors, which housed several shuttles of different types, including the Type 7 shuttlecraft. ()

 Accommodations 
Senior officers, such as the captain, had private quarters below decks. Captain Hikaru Sulu's quarters were located on Deck 3. 

Many of the enlisted crew, junior officers and officers shared quarters and bunk areas. They varied in occupant size from four to nine. (; )

 Ships commissioned 

 Appendices 
 Appearances 
 :
  
 
 
 
  
 
 
  
 
  
  
  
 
  
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
  
 
 
  
  
 

 Background information 
According to the script for Star Trek III, the Excelsior was described as "a super starship. Her lines are similar to Enterprise, but she is clearly bigger, sleeker, and very new. She sits at her mooring like the new Queen of Space." In relation to the Enterprise, "their size differential is apparent ( to )."

 Studio models 
See Excelsior class model

 Size 
The generally accepted length of 1,531 feet (466.6 meters) can be traced back to a size comparison chart developed for  and published in the June 1987 issue of Cinefantastique. The related comment below was posted by Bill George of ILM:

"I really don't think there is a definitive answer to this question. The only description we had at the time was that it was "souped-up" and bigger than the Enterprise. The size the miniature was built to was determined by the camera guys as being the optimal size to shoot. As I recall Nilo [Rodis-Jamero] did that size comparison chart, but it wasn't necessarily followed. The issue of true scale wasn't a consideration. Budget, ease of use, art direction and dramatic intent were what influenced the construction of the ship." (The Trek BBS)

Andrew Probert extended the ILM chart for , sizing his Ambassador concept halfway between the Excelsior and the Galaxy.  Visual Effects Supervisor Gary Hutzel would use 1,500 feet around 1998. 

 Technical Manual 
The following information of specifications and defenses comes exclusively from the Star Trek: Deep Space Nine Technical Manual:

 Production Base: ASDB Integration Facility, Utopia Planitia Fleet Yards, Mars
 Type:	Explorer
 Accommodation: 750 officers and crew; 130 visiting personnel; 9,800 personal evacuation limit
 Power Plant: One 1500 plus Cochrane warp core feeding two nacelles; one impulse system
 Dimensions: Length, 511.25 meters; beam, 195.64 meters; height, 86.76 meters
 Mass: 2,350,000 metric tonnes

 Apocrypha 
The advent of the Excelsior design and transwarp are referenced in Diane Carey's  Battlestations! and licensed reference book Mr. Scott's Guide to the Enterprise by Shane Johnson. 

Shiplists and specifications of many unseen and conjectural Excelsior-class vessels are included in many role-playing game supplements such as the Federation Ship Recognition Manual and the TNG Officer's Manual from FASA, and the Decipher sourcebook .

According to the novel Ghost Ship, some Excelsior-class ships in the 24th century have the ability to separate their saucers, including the  and the Hood.

In the ization of  Captain Sulu was performing an emergency saucer separation drill aboard the  when he receives word about Kirk's death aboard the .

In the video game Star Trek: Elite Force II, the player character leads a mission aboard the Excelsior-class vessel  (NCC-2019). The dedication plaque states that the Dallas is the "last starship of her class."Star Trek Online features the Excelsior-class and her refit as a commander level (Tier 3) "Advanced Heavy Cruiser" and rear admiral level (tier 5) "Advanced Heavy Cruiser Retrofit" respectively. This ship is equipped with a Transwarp Computer allowing you to Transwarp to different Sector Blocks. A Tier 6 Excelsior is now available on Star Trek Online'' alongside a fleet version.

External links 
 
 

bg:Клас Екселсиор
cs:Třída Excelsior
de:Excelsior-Klasse
es:Clase Excelsior
fr:Classe Excelsior
ja:エクセルシオ級
nl:Excelsior klasse
it:Classe Excelsior
Federation starship classes