In the recent episode S03E06 of Star Trek: Discovery, USS Discovery got lots of upgrades

like detachable warp nacelles held by programmable matter (guess they are going to blow in a future episode) and programmable matter based controls,

but one possibly overlooked major upgrade was its registry number:

USS Enterprise NCC-1031-A

(A new letter has been added to USS Discovery's registry number; previously, it was NCC-1031 and now it's NCC-1031-A)

Why did the Federation change the registry number of USS Discovery? Even with the major upgrades, it's the same old ship with Spore Drive unaltered.

Historically, we've seen that a new incremental registry number is assigned to a new ship and that's also when it replaces a destroyed ship of same class. In Star Trek: First Contact movie, when Picard initialized self-destruct sequence of USS Enterprise NCC-1701-E, Picard and Beverly Crusher had this conversation:

Crusher: Think they'll build another one?
Picard: Plenty of letters left in the alphabet.

Talking about Federation's logs according to which USS Discovery was destroyed long ago, the logs can be rectified. Yes, Time Travel was a crime, but Federation was the ultimate authority there. If they trusted USS Discovery and knew that it wasn't involved in temporal war, why couldn't they simply pardon it or change the law?

Why did they change the registry number of USS Discovery?

I want to know answer from both in-universe and out-of-universe perspective.

  • 2
    “it's the same old ship with Spore Drive unaltered” — the Spore Drive that's one of the Federation's oldest and best-kept secrets, and could now be a crucial tactical advantage in a galaxy with scarce warp drive capability, on a ship that fled to the far-future to evade an artificial intelligence bent on using the sphere data contained in the ship to destroy all life in the universe. I think slapping -A on the end is the least they can do. Commented Nov 25, 2020 at 11:22
  • @PaulD.Waite What's your point? Spore Drive was a secret even in the past. If you're talking about protection from the AI which might still be waiting in the dark for USS Discovery after doing The Burn, they should have changed the entire name of USS Discovery and also maybe change the external hull structure.
    – user931
    Commented Nov 25, 2020 at 12:13
  • What about the existence of the Terran Discovery in the prime universe? As that one was destroyed in the prime universe, it's possible that the "modern Starfleet" think that our Discovery was built to replace that one Commented Nov 25, 2020 at 13:36
  • 1
    @UmbrellaCorporation: Starfleet security famously half-asses things. Commented Nov 25, 2020 at 14:06
  • 2
    I'm glad I'm not a 32nd-century philosophy student needing to write a paper about how the Ship of Theseus question applies to programmable matter. Commented Jan 7, 2021 at 20:08

3 Answers 3


Registry changes with letters seem to indicate "Generations of Evolution", not necessarily new ships

When we see the USS Voyager in Season 3, Episode 5, "Die Trying", here is what the bridge crew has to say about this:

TILLY: The USS Voyager. (laughs) J. That's... ten generations of evolution?
OWOSEKUN: Eleven. Would love to hear those stories.

This interpretation actually fits the registry changes of the USS Enterprise, which were not only carrying the name to honor the older ships, but can be considered a new evolutionary step for the ship and its respective crew.

However, it's also a good explanation to why the USS Tikhov is referred to on-screen as a ship that has been active for hundreds of years - it has the registration number NCC-1067-M, so we could assume that it has been through 14 "stages of evolution".

It would also explain why the USS Dauntless has already the letter -A attached to it, even though this ship is the first of its class (a prototype, even). With this explanation, they have overhauled the prototype once, justifying a registration change.

At least in my own head, it makes also a lot of more sense to see the USS Relativity with the registration number NCV-474439-G as the eighth iteration of the same ship, rather than as the eighth actual ship with that name.

And then, of course, there is the USS Nash with the registry number NCC-2010-5, and the SS Columbia with NC-5940-1, and the USS Yamato, which changed its registration from NCC-1305-E to NCC-24383 and even NCC-71807. This has never been commented on on-screen, and according to Memory Alpha, at least one of these registration numbers has been a mistake. All these seem to indicate that the system in which registration numbers are assigned are not as iron clad as we, the fans, would like to believe.

In conclusion, after the upgrade which is seen on screen, the Discovery definitely qualifies as "a new generation", which apparently results in a new letter.

However, as pointed out in the comments, that's apparently not a hard-and-fast rule, as the refitted NCC-1701 Enterprise did not receive a letter, and the Defiant-A received the same name, but an additional letter, even though the ship was more or less identical, and certainly not a new "generation".

  • 4
    I down voted because it ignores the obvious facts that the Enterprise A and Defiant A were different ships and not upgrades. Also the fan blaming. Commented Nov 25, 2020 at 15:43
  • 1
    Please help me understand how the defiant a and enterprise a relate to my post? They are new ships all right, same as all the different enterprises. And where do you feel that I am blaming fans, and for what?
    – Philipp
    Commented Nov 25, 2020 at 16:02
  • 5
    This doesn't really fit with the refitted Enterprise (NCC-1701) not being given a suffix. Unless you think the refit didn't count as a "stage of evolution"? The ship was pretty different.
    – Muzer
    Commented Nov 25, 2020 at 16:27
  • 1
    Answer doesn't realize the Dauntless was a fake ship from an alien bent on revenge. This is the same problem star trek writers now have - they skim wikipedia articles to seem like they know the material. Commented Nov 25, 2020 at 20:49
  • 3
    @Muzer In the 80s and 90s it was a significant topic of fan discussion whether the Enterprise Refit and Enterprise-A were the same class of ship as the original Enterprise 1701. Eventually the TNG Technical Manual definitively settled this: they are all Constitution-class. But the Refit Enterprise and Enterprise-A are almost identical in design, but are very different from the original 1701. But the Enterprise pretty definitively rules out this theory: Either there should have been an extra letter during the refit, or the 1701-A shouldn't have been labeled A. Commented Nov 25, 2020 at 22:35

There is not an in-universe answer or likely will be. At best you might get a comment in tie-in media if some author thinks it's worth commenting on.

A reasonable theory I have seen is the -A is to hide the fact it is a thousand year old ship to the casual registry reader.

Or someone decided enough stuff was changed to justify it.

Out-universe this is an easy way to distinguish the ship model merchandise. This is almost certainly the primary answer.

Discovery writers don't strike me has the type of people that understand that a refit is the same ship and has not previously been cause for a registry change.

  • 6
    I downvoted, because this answer mainly says "They did it for the money, and they don't know enough about the Star Trek canon". This sounds more like your own opinion about the show and the authors, and less like an objective answer.
    – Philipp
    Commented Nov 25, 2020 at 8:13
  • I think you make a good point about merchandising; TMP Enterprise is awkwardly known as "NCC-1701 (refit)" and there's no clear distinction between the refit and NCC-1701-A.
    – Anthony X
    Commented Jan 9 at 22:00
  • The fan boys like their letters, +1. I don't even remember why it's important that it's the 1701 D. But it is. Like wow man. We just watched a ship get a new letter. That's like once every Generation.
    – Mazura
    Commented Jan 11 at 5:21

Another point apart from the excellent response from Philipp might be in order to avoid detection of the USS Discovery's breach of the temporal accords. See below video from Star Trek: Discovery “Die Trying” (S03E05); starts about); 56 seconds in:

Transcript (emphasis by me):

Admiral Charles Vance: A quick history lesson. The Federation has spent most of the 30th century fighting a war to uphold the temporal accords. An interstellar treaty outlawing time travel to prevent anyone from the past from changing the future and vice-versa. Your presence here, by definition, is a crime

So, by changing the registration from NCC-1031 to NCC-1031-A, it gives them plausible deniability. They can argue that the USS Discovery is not the same as the one from the 23rd century but a new ship named in honour of an existing ship that vanished in the service of the Federation.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.