The USS Defiant (NX-74205) and other ships of its class were developed as experimental warships by the Federation to fight the Borg. These ships had massive and powerful armaments including phaser cannons and quantum torpedoes, strong defensive mechanisms such as ablative armor, and minimal accommodations for crew, lacking a full sickbay, most scientific instruments, and all of the luxuries of a standard 24th century Federation vessel.

So far, this makes sense for a warship. However, there is one thing about the Defiant's design that has always confused me: its size.

The largest (canon) Starfleet Vessel from the 24th century that I know of is the Galaxy class starship at 42 decks and 2108 feet (643 meters) in length. The "standard" fleet vessel was the Excelsior class, which measured in at 34 decks and 512 meters.

The Defiant class on the other hand has only 4* decks and measures only 170 meters. Here is a visual comparison:

Defiant Versus Lakota

Taken from the battle between the Defiant and the Excelsior-class USS Lakota in DS9: Paradise Lost.

So the question is: Why is the defiant so tiny?

Starfleet had thousands of ships at this point, and was mass-producing Galaxy-class vessels, so resources certainly weren't an issue. Also, basic surface area to volume ratios dictate that a smaller ship would have a much greater vulnerable surface in proportion to its internal systems.

Is there some tactical advantage to be gained from a small vessel (in terms of fighting the Borg)? Maneuverability wouldn't seem to matter, considering the Borg tactic of sitting in one place and blowing up the ships flying around you.

Were the Defiant's tactical systems so powerful that the warp core couldn't power a larger ship? Was this ever discussed on screen? Did starfleet intend to mass produce these things and have them operate as "swarms"?

Canon answers appreciated, but deductions and basic logic are as well. Thank you in advance.

  • 11
    I'll leave it for someone else, but I can bet (if the writers were consistant) they could roll out a few dozen Defiant-class vessels in the same time it took to make a single Galaxy-class vessel.
    – MPelletier
    Commented Jun 4, 2013 at 23:36
  • 10
    Another factor to think about it, the Defiant was unoffically a "warship" warships don't need to have extra room or decks as like the Galaxy class ships, as they weren't built for exploration, they were made for combating the borg and other baddies :D
    – Jared
    Commented Jun 4, 2013 at 23:47
  • 9
    Snarky answer: At the same distance, is it easier to shoot a wolf or an elephant?
    – Izkata
    Commented Jun 5, 2013 at 0:58
  • 2
    @Izkata Snarky reply: When you're the Borg, do you give a damn? They didn't seem to have a hard time nailing the Defiant in First Contact. Commented Jun 5, 2013 at 6:12
  • 8
    Most Starfleet ships are built to be Swiss Army Knives; they do a bit of everything. The Defiant was built to fight Borg, fight Borg, and give Worf something to do on DS9. Commented Mar 25, 2016 at 14:04

15 Answers 15


In the case of the Defiant, size matter less in terms of their ability to deal out damage versus the benefits of being a fraction of the previous size of most Starfleet vessels. The Defiant, with its weapons outfit, can put out the same damage potential of a Galaxy Class Starship in a much more nimble, highly armored and difficult to hit package.

  • While cost of production is not necessarily a factor, time to produce is. If I can make six Defiant-class ships in the same time as it takes to make one Cruiser class ship, I will always take the six ships over the one. Especially if the damage dealing capacity of that one ship is half that of the Defiant class ship. Same number of crew are required, but I have six nimble targets for the enemy to shoot at and six ships capable of attacking opponents, capable of dealing six times the damage of a single Galaxy Class Ship.

  • Since the weaponry of the Federation is both powerful, and easily able to fit on almost any ship (as long as it has a warp core power plant) there is no rationale for placing weapons on a single ship which might be more effective being spread out over a half dozen ships.

  • The factor of size is negated if you are not able to protect that ship from attack effectively. The reason the Borg get away with such immense ships, is their resilience to damage in combat. Alpha Quadrant races depend far more on shields than they do on redundant systems or sheer mass to overcome their enemies.

  • Size limits the ability to coordinate technology effectively, the larger the ship and crew, the slower the coordination; Borg ships evidently benefit from their hive mind intellect enhancing their overall combat performance. In this case, a ship is only as effective as the minds coordinating it or the technology protecting it.

  • In the case of the Defiant, a smaller ship, is a more nimble, faster, better coordinated and less likely to be easily destroyed ship.

Defiant Class Starships: an escort sized vessel with phased cannon arrays, quantum torpedoes and defensive armor as well as enhanced mobility made it more than capable of dealing damage equivalent to that of a Galaxy-class starship. Her armaments included:


  • 4 x Class I rapid fire phaser pulse cannon
  • 3 x Phased Beam Emitters, 2 forward, one aft, standard phaser array
  • 6 x Pulse fire Quantum/Photon torpedo tubes + 100 torpedoes four forward, two aft
  • 1 x Probe / Photon torpedo launcher - equivalent to standard photon torpedo tube + 20 torpedoes

Defense Systems

  • Auto modulated high capacity shield system, total capacity 2,376,000 TeraJoules
  • Heavy Duranium/Tritanium double hull plus 20 cm Ablative armour.
  • High level Structural Integrity Field

This was a warship, pure and simple, designed to deal out damage in all directions with variable phasers which could vary their frequency preventing the Borg from easily adapting to them and Quantum torpedoes who damage capacity eclipsed the photon torpedo by orders of magnitude; same box, much bigger bang.

  • 4
    Why does everyone seem to think smaller means quick and nimble and large means slow and ponderous? In space large is also quick and nimble... with a lot more firepower at hand.
    – Morgan
    Commented Jun 5, 2013 at 2:56
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    I that know in the StarTrek universe, spaceships bank and dogfight like fighterplanes in atmosphere but it's not necessary to perform such aerobatic maneuvers in space. Spacechips can actually spin or roll on their axis to keep their main 'fwd' guns locked on to and tracking targets. The Defiant is "A tough little ship", no doubt but I would rather be shooting at an adversary with 20 Class I rapid fire phaser pulse cannon, 15 standard phaser arrays and 30 Pulse fire Quantum/Photon torpedo tubes with 500 torpedoes on tap. Just sayin'.
    – Morgan
    Commented Jun 5, 2013 at 4:52
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    For the same cost, @Morgan you can have all that, only split up into a squad of Defiants. That's an even better position to be in.
    – DampeS8N
    Commented Jun 5, 2013 at 14:48
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    @Morgan: In space, there's nothing to slow down a larger ship, true, but unless the drive is reactionless, it still takes time to get the mass moving. Less massive means it can accelerate quicker.
    – Jeff
    Commented Jun 6, 2013 at 13:05
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    @Morgan, yeah gravity may not be a factory, but inertia still is. The less mass you have, the easier it is to start, stop, or deflect that mass. In fact, there are several cases in DS9 in which we see the Defiant zipping in and out while much larger vessels are heading straight in.
    – Matt
    Commented Mar 20, 2014 at 14:01

Earth's history is "included" in the Star Trek universe and you don't have to go any further than the WW2 US Navy for something equivalent to the thought process behind the Defiant. PT boats were small, fast, inexpensive and carried a punch much higher than their size indicated. Though unlikely, a PT could even take out a battleship or aircraft carrier in theory with its four torpedoes.

“The PT boat squadrons were nicknamed "the mosquito fleet". The Japanese called them "devil boats".”

The Defiant, when seen in combat, always reminds me of how the PT boats could maneuver during a battle. They weren't impossible to hit, but it was very hard to hit them. Of course, for the PT boat all it took was one hit.

  • 1
    I've tidied your comment a little to remove the "chatty" elements. Stick to giving an answer and you can't go wrong.
    – Valorum
    Commented Mar 20, 2014 at 17:48

The out of universe reason: The creators of the defiant were told it has to be a small ship:

They were like- fine it can be small, but it Has to be Really Powerful.

They don't explain the reason for it "having to be small", but I'm guessing to cut costs, so they could reuse old shots of the Station without having to add a new big ship every time. The Defiant's so small, you don't have to see it every time you see the station.

  • Welcome to SFF.SE! Nice out-of-universe find!
    – Skooba
    Commented Sep 8, 2016 at 12:49

The size of the Defiant is not consistent. Check this page, which includes the screen cap in your post as well as others for a full discussion:

The Defiant is most often shown at a size of roughly 120m, but there are exceptions ranging from 50m to 170m.

  • Good info, but 170 meters is still pretty small. Commented Jun 7, 2013 at 4:22
  • Yeah it's only a partial answer not a complete one. The thing is that Star Trek, like most TV series, has some strange inconsistencies due to having lots of writers/producers/executives all wanting to add their cool thing to the latest episode. Which means that for some questions they're just aren't good explanations.
    – user8416
    Commented Jun 10, 2013 at 9:22
  • It is a good incomplete answer, and for that you get an upvote. Commented Jun 11, 2013 at 5:39

There are several great answers here, but I'll offer one more: the Defiant was a prototype. For decades, Starfleet had built hybrid science-and-exploration ships, for whom war fighting was a secondary role. The Defiant was something new, an experiment. You don't build a huge battleship until you've tested whether you can make a solid destroyer.

If the wars and near-wars with Cardassia, the Dominion, and the Borg had continued, you'd expect to see existing hulls refitted for wartime service (as seen in All Good Things) and new larger purpose-built warships (the Sovereign class was a step in that direction; the Prometheus was a perfect example of a medium-sized dedicated warship).

However, the Federation would probably have never built a true battleship, comparable to a Negh'Var, say. Very large warships have historically been built for ego more than practicality, and the Federation's deep pacifist side would not be keen on building impractical war machines just so admirals could compensate for their inadequacies.

  • 1
    At least until Admiral Marcus in the JJ-alternate universe.
    – eidylon
    Commented May 19, 2014 at 15:50

The main reason for such a small ship designed to fight the Borg, is to minimise the number of crew required to operate the ship and thus prevent Wolf 359 again, 11000 personal were lost out of those 40 ships. Send a crew with 30-50 people on basically a weapons platform and thus thats why we have the Defiant.

  • 3
    This actually seems pretty logical. If you could back it up with a quote or reference this answer would go from good to great.
    – Valorum
    Commented Oct 3, 2014 at 0:21
  • With the level of automation we see on Starfleet ships, it doesn't seem logical to assume that there is a sharp correlation between ship size and crew requirements. A good chunk of the Enterprise-D is taken up by recreational facilities, science labs, VIP suites, classrooms, and other facilities that could be shut down during wartime deployment and protected by a half dozen security drones. All of those scientists, teachers, diplomats, holodeck game authors, etc. aren't obviously needed if all you really need is to fly the ship and shoot Borg. Commented May 14, 2022 at 14:21

Also think about the shields. Granted the Defiant had ablative armor but it's primary defense is shields. A single shield emitter covers a specific area of the ship. For something the size of the Enterprise D a single emitter may only cover a small portion of the ship. So a LOT of emitters are needed to cover the entire ship. Now each emitter has to not only cover its area but half that of its neighbor as well so if one emitter fails, the two on either side can take up the slack. And the more you have the more that can fail. With a smaller ship like the defiant it takes a great deal fewer emitters and the ones that it does carry covers much more of the ship with a great deal more overlap. So if one fails it is easier for the others to take up the slack and you end up with stronger and more resilient shields as a side effect. Also if a shield should fail, repair or replacement is faster with shorter distances to cover for your repair crews.


From Memory Alpha:

The port side of the bridge housed the engineering and tactical I stations, while the starboard side featured the science and tactical II consoles. Because of its nearly exclusive role as a combat vessel, stations aboard Defiant-class vessels were designed with speed in mind.


The engineering station allowed for a direct link to the impulse and warp engines, as well as monitoring of the other various systems vital to the operation of the ship. This single station was capable of mirroring all the readouts and consoles located in main engineering, allowing the chief engineer or another engineering officer to issue commands from the bridge.

Emphasis mine. The compact construction of the ship would allow the crew to gain quicker access to all areas rapidly - the ship was designed with internal speed in mind. A larger ship would mean much longer delays as crewmembers moved to their stations. So, it's less a factor of ship speed, and more a factor of internal speed.

Also, an out-of-universe answer from the same page:

The main problem with the design at that stage was that it didn't look fast enough, so Meininger, a car enthusiast, got some posters of Ferraris, and used them to help him design the 'streamlined' look of the ship, making it very compact and sleek.

Indeed, Herman Zimmerman has stated that the compact design of the Defiant-class influenced the design of the Enterprise NX-01 for Star Trek: Enterprise. He also pointed out, "It was very clear it could not look like NCC-1701-A, B, C, D. It was to be an entirely new ship." (The USS Defiant, DS9 Season 3 DVD special features; Star Trek: The Magazine Volume 1, Issue 4, Star Trek: The Magazine Volume 1, Issue 13; Star Trek: Communicator issue 105)

Essentially, the ship was designed to look much smaller because it gave it the appearance of being much faster than other starfleet ships.



I'd say it's because, given the Defiant's missing, a larger ship would be wasteful.

The Defiant has a "punch" similar to a much larger vessel, and that offensive capability is most of what it's designed for. It doesn't need science labs, complex medical facilities for dealing with Mysterious Plague X, etc. That also means it doesn't need scientists, who I imagine probably made up a large portion of the typical Galaxy class complement, so those quarters, number of medical beds, food replication equipment, can all be left out.

Though it's not outright stated, I'd also imagine that the typical mission was expected to be of much shorter duration than an exploratory mission such as the larger ships are often sent on. So the recreational facilities are probably minimal. And there's likely very little provision for family members.

Other than offensive capability, I'd say the Defiant is also engineered for survivability. It's shown manuvering at impulse in ways we've never seen larger ships approach, and it has ablative armor that we've never seen on larger ships. A small mass could help with the first, and a small volume could help with the latter.


During WW2 the USA was mass producing heavy cruisers, but made fletcher destroyers much faster and in larger numbers. Cruisers had greater range, endurance armor and weapons, but Fletcher's became the workhorse of the fleet. The same applies here, a cheaper ship with fewer crew that can be made in far greater numbers, with the ability to engage in large fleet actions, or to be used in routine patrols/escort duties.


In terms of its initial purpose, which was to be a warship, the Defiant's size helped to reduce its size as a target, which, coupled with the agility that this afforded, effectively made it impossible to hit. Secondly, its total armament was similar to most of its contemporaries, but its small size, speed and agility meant that it was at little risk of taking hits to the top, bottom or sides, so the weapons could be heavily concentrated forwards and backwards, rather than spread out 360°.

When it was refit and assigned to DS9, it was intended for short-range operations in potentially hostile territory. As it is easier to locate a large ship than a small one, it minimised the chance of detection in the event that a hostile power (such as the Borg or Dominion) was in the area.


The Defiant is designed for one mission unlike a Galaxy class which is designed to perform many different missions.

The Defiant is the equivalent of today's corvette or smaller fast attack ships: gun boats, missile boats and patrol boats. It has low endurance. It's intended for out and back missions.

A Galaxy class can absorb large amounts of battle damage and concentrated fire and still survive by virtue of it being physically larger. A Defiant class cannot. But being smaller makes an Defiant class easier to hide. You cozy up to a large asteroid in a belt, power down and hide, waiting for a target to come by. You can't do that as easily with a Galaxy class.

The Defiant is essentially expendable where a Galaxy class is not. Defiant style ships get sent to places to do missions they're likely not to come back from.

  • Do you have any evidence to support the claim that the Defiant has endurance than the Galaxy class? I was under the impression that the Defiant was built to be much, much tougher. Commented Apr 19, 2016 at 6:19
  • @ApproachingDarknessFish Endurance and toughness are not the same thing.
    – T.J.L.
    Commented Apr 19, 2016 at 13:42

maybe my reply is a bit too late, i think the the size does matter in terms of maneuverability which can make it a bit harder to lock on by torpedoes, even if gravity is not a factor in space, the mass of ships matters... i think imo factors for the size is production quantity compared to a galaxy class, maneuverability, and nimbleness

the test wasn't really a failure when sent out into the gamma quadrant, what happened to the prototype was within expectation since it has its flaws until Chief O'Brien fixed those flaws and became a successful anti-dominion armada, you cant really compare the structural integrity of a defiant to a galaxy since the galaxy class has more alloys in it to resist damage, but do keep in mind even if the defiant is more fragile than a galaxy class.... the defiant can go around larger ships away from its main arsenals and attack the larger ship's weak side

  • No answer is too late! :) However, could you elaborate on this? A bit more information (ideally supported by some quotes from the TV series, films, etc) could be helpful
    – Adamant
    Commented Oct 14, 2016 at 5:09
  • well to make a bit more simple, even in space the lesser the mass of an object the easier for it to move about, as we all know there is no weight in space because there is no gravity but it doesnt mean you can push away a ship with your bare hands compared to pushing a baseball in space, because baseball has a much much lesser mass it can easily be propelled by your hands by throwing it or pushing it which is almost impossible when you do it to a car same principle applies for those starships with their engine its easier to accelerate and move around from a defiant class than a galaxy class
    – AltOa
    Commented Oct 14, 2016 at 5:30
  • OK, good. Would you integrate this comment into your answer?
    – Politank-Z
    Commented Oct 14, 2016 at 7:12

While the Defiant was a radically new ship design, it was still made out of familiar components, and follows similar design principles.

In particular, like any Federation ship, it still draws its power from a warp core, which only produces so much power. The Defiant is what you get when all of the power from the largest size warp core is funneled towards military purposes. The ship isn't any bigger, because it's already big enough for everything to fit.

While they could have designed a new warp core with even greater energy output, that would dramatically increase development time and costs, and building a ship around an unfamiliar core with unfamiliar engineering ramifications would open up more ways that the design could fail.

As it is, the prototype barely held together when tested at full power!

Ultimately, there would have to be an extremely compelling reason to try and build a larger, more powerful ship when you could just build more, smaller ships.


The Defiant was a tactical escort, a pocket warship, they took the systems and component hardware of larger ships and placed it all in a compact frame. There's little space for luxuries or even logistics for long term endurance. It is NOT a battleship for long term sustained operations, in essence she is a heavily armed corvette. In the DS9 episode "The Search" which chronicles the Defiant's first appearance and it's history. "The Defiant was the prototype, the first ship in what would have been a new Federation battle fleet." This would seem to imply Starfleet would not have deployed ONE ship but to have them in mass. In essence operate like a pack of wolves than a single predator. The Sovereign or Galaxy class is an Explorer-Battleship hybrid; meant to show the flag and serve it's diplomatic and scientific roles but if NEED be, defend itself or put up an offensive. Very large warships have historically been built for ego more than practicality as seen in World War II, as navies transitioned from battleships to aircraft carriers, infamous navies like the UK and US saw their pinnacle ships sank by cheap airplanes. The Defiant is the closest approximation to real world navies smallest naval unit that can operate independently a Corvette, fulfilling the roles suited for a vehicle that size and did so in several episodes. - Interdiction (Ep: The Adversary) - Starship combat - Convoy escort (Ep: Rules of Engagement) - Troop landing (in environments where transporters are useless) - Mobile command center (land on a planetary surface and act as base) - Territorial/Border Patrol - Reconnaissance The cost of production is not necessarily a factor, time to produce is. The Defiant's size simplified manufacturing, If I can make six to ten Defiant-class ships in the same time as it takes to make one big Cruiser class ship, I will always take the fleet of ships over the one.enter image description here

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