Does the “USS” in “USS Enterprise” imply that this is a Starfleet starship? I.e., that it’s under quasi-military or government (or whatever you consider Starfleet to be) command rather than purely civilian?

Much as the “USS” in “USS Ronald Reagan” denotes that it’s a US Naval vessel.

This question is inspired by the answer to this question (Can a private citizen of the Federation legally obtain a starship?) which references the USS Raven.


3 Answers 3


No, but it's complicated

Please note that there are two types of prefixes described:

  1. The name prefix, followed by ship's name. Indicates the origin/owner of the vessel. Examples:

    1. USS in USS Enterprise
    2. IKS in IKS Rotarran
  2. The registry prefix, followed by ship's registry number. Indicates the type/purpose of the vessel. Examples:

    1. NCC in NCC-1701-D
    2. NAR in NAR-32450
    3. XCV in XCV-330

Pre-warp era

Ships with a name prefix USS from the pre-warp era on Earth belonged to the United States of America. The abbreviation stood for United States Ship. There was no Starfleet at that time, therefore it didn't mean that it was a Starfleet vessel, which gives a NO.

Post-warp era, pre-Federation era

The USS Enterprise (XCV-330) definitely has a USS prefix, however, it is not clear who was the owner of this spaceship. The ship was in service some time before 2143 and Starfleet was probably founded in mid-2130s. It is possible that the ship was owned by another entity, possibly United Earth.

Federation era

All ships that had a USS name prefix at that time belonged to the United Federation of Planets. The abbreviation stood also for United Star Ship or United Space Ship.

It is a bit vague if all Federation ships belonged to Starfleet.

For example, the USS Raven was given to the civilian scientists by the Federation Council on Exobiology. It is unknown if the ship had ever been a Starfleet vessel (and was simply temporarily given to civilians), or was it a part of fleet that was not subject to Starfleet (but to UFP).

In a not completely canon Star Trek: Voyager Technical Manual we read that:

NAR (registry number) prefixes were among those used on vessels that were non-Starfleet but still under Federation jurisdiction.

Italics mine.

USS Raven was designated as NAR-32450, which places it as a ship under UFP jurisdiction and outside of Starfleet. This gives an answer: NO.

Given that in the whole history in the Star Trek universe there were examples of starships who had a USS prefix but were not operated by Starfleet, the final answer has to be:

No, a USS name prefix does not imply a Starfleet vessel in 100%, but it is a good approximation.

  • Sorry, I mangled the question and fixed it in post. I meant whether USS meant it was owned by Starfleet rather than under private or civilian ownership.
    – RoboKaren
    Commented Jul 9, 2018 at 11:04
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    You seem to be implying that NX & NAR are alternatives to USS instead of alternatives to NCC.
    – tjd
    Commented Jul 9, 2018 at 16:19
  • Yes, @tjd is right. TOS "USS Enterprise" is "NCC-1701". These are orthogonal to one another. That "USS Raven" was "NAR" rather than "NCC" didn't affect the "USS" part one little bit. Commented Jul 9, 2018 at 18:53
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    @tjd - maybe I have not distinguished properly the primary prefix (USS) and the secondary (NCC/NAR), I will do that in the morning ;) Commented Jul 9, 2018 at 20:52
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    The registry prefix seems to indicate something about how the vessel was built / acquired. NCC stands for Naval Construction Contract, NX stands for Naval experiment. What NAR stands for hasn't been established in-universe Commented Jul 10, 2018 at 15:16


The problem is, there aren't a lot of non-Starfleet Federation ships to go around, which not only makes it harder to spot the pattern, it makes the producers less likely to have gone to the trouble of coming up with a pattern in the first place.

One unambiguously civilian ship is Kassidy Yates's freighter, the SS Xhosa. However, this ship was not (directly) registered to the Federation, but to a race called the Petarians, who didn't seem to be Federation members (or at least they didn't have access to Federation-standard technology).

The USS Raven, as you mentioned above and was discussed in the other answer, it another point. This is evidently not a Starfleet ship, but registered under the auspices of some other Federation body.

On the gripping hand, there are ships like the SS Tsiolkovsky (from the early-TNG episode "The Naked Now") that are implied to be Starfleet ships, but have SS rather than USS prefixes. Another possible case is the SS Vigo (TNG: Hero Worship) which is on some kind of mapping expedition for the Federation, but may or may not be a Starfleet ship.


I don't know if you want a purely in-world explanation, but any explanations for this using in-world logic are probably just retrofits. The writers were making up this universe as they went along. My wife and I rewatched TOS in order recently, and as we watched the episodes in the order they aired (which is probably at least approximately the order in which they were written), it seemed pretty obvious that the writers had no clear concept of the society that had built the Enterprise and sent her on her five-year mission.

I think they simply used "USS" because it would be familiar and understandable to viewers as a prefix naming a ship. Nobody had ever done anything like this on TV before, and they were concerned that people wouldn't be able to understand what was going on. I've read that they made a conscious decision to use place names like Vega VII and Altair VI, because they were star names that people would know, even if it wasn't scientifically accurate. In the episode about the salt monster, there's a story that they tried to find a futuristic-looking salt shaker, but they were afraid the audience wouldn't know what it was, so they ended up grabbing an ordinary-looking one from the commissary.

With hindsight, it would have been more logical to use something like FS for Federation ship. But I don't think there was any Federation in the early episodes. IIRC, the Enterprise is referred to as an "Earth ship." The crew was 99% human, probably partly for budget reasons and partly because they wanted the characters to be relatable, and nobody bothered at first with explanations of how this all fit within any bigger political structure.

  • 7
    According to (Memory Alpha's gloss of) Stephen Whitfield's The Making of Star Trek, Roddenberry actually got in a fight with the network execs over how to prefix the ships - the execs wanted a specifically United States starship, Roddenberry thought that didn't fit his vision. USS, with the canon expansion, was presumably the compromise they reached.
    – Cadence
    Commented Jul 10, 2018 at 0:01
  • @Cadence: Your comment is probably of more value than my answer. If you'd like to edit it in to the text of my answer somehow, that would be great. Do you have a link to the info on Memory Alpha?
    – user2490
    Commented Jul 10, 2018 at 1:45
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    The discussion of "United Star Ship" vs. "United States Starship" is recounted in the background section of the USS prefix's own article. (I was a little surprised there was such a thing, but there is.)
    – Cadence
    Commented Jul 10, 2018 at 2:25

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