Assuming a Galaxy class starship were to work on a regular schedule (i.e. exploring, diplomatic missions etc. but NO battle), how long can it last before it has to return to a starbase for servicing?

I appreciate this may be difficult finding a series of episodes from TNG where the Enterprise-D does not battle between going to a Starbase, so, if it is absolutely necessary, battle can be included, but no major damage...

  • Not an answer, but this question may provide insight. scifi.stackexchange.com/questions/15576/…
    – Xantec
    Apr 4, 2014 at 0:39
  • @Xantec - thanks for that I can see the relation to it, but as you say it doesn't really address what I'm looking for ;) Apr 4, 2014 at 0:42
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    not sure about a full service - but the ship had a "baryon sweep" in Starship Mine which seems to be the equivalent of an oil change
    – HorusKol
    Apr 4, 2014 at 1:26
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    Well, the Enterprise is sent on missions lasting up to five years. They wouldn't send out a ship for that long of a time if they weren't sure it could stand it. Maybe seven, eight years without servicing? Apr 4, 2014 at 3:26
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    According to the TNG technical manual, the warp coils must be de-neutronised at stardock every 2000000 cochrane-hours. 200 years at warp 1 or around 7 years at sustained warp 6
    – Valorum
    Apr 4, 2014 at 7:24

3 Answers 3


3 Years (ish) of normal operations

Whilst the TNG Technical Manual suggests that the Enterprise has the theoretical

"ability to operate independent of starbase refurbish-ment for extended periods. Independent exploration mode capability of seven Standard years at nominal Warp 6 velocity for docked configuration. Ability to execute deep-space exploration missions including charting and mapping, first cultural contact scenarios, and full biologic and ecologic studies.

the reality is that there are a number of service issues that would affect their ability to do so.


The Enterprise-D seems to have sufficient antimatter (and Deuterium matter) fuel supplies to undertake 3 years of a normal mission profile without the need to refuel.

Each pod contains a maximum volume of 100 m^3 of antimatter, giving a 30-pod total starship supply of 3000 m^3, enough for a normal mission period of _three years_. Each is connected by shielded conduits to a series of distribution manifolds, flow controllers, and electro plasma system (EPS) power feed inputs.

The total internal volume, which is compartmentalized against losses due to structural damage, is 62,200 m^3. As with the volume of antimatter loaded for a typical multimission segment, a full load of deuterium is rated to last approximately _three years_.

Warp Core

The same source also notes that the engines must be maintained (at Starbase) every 10,000 hours of usage (approximately 1 year). Assuming the average mission requires a day of travel for every two days of actually doing stuff, this also works out to around 3 years

Standard in-flight preventative maintenance is not intended for the warp engine, since the core and the power transfer conduits can be serviced only at a Starfleet yard or starbase equipped to perform Class 5 engineering repairs. While docked at one of these facilities, the core can be removed and dismantled for replacement of such components as the magnetic constrictor coils, refurbishment of interior protective coatings, and automated inspection and repair of all critical fuel conduits. The typical cycle between major core inspections and repairs is 10,000 operating hours.

Warp Coils

The primary and secondary Warp coils also need "neutron purge refurbishment" every "2,000,000 Cochrane-hours". Given that a warp six field is 392 Cochranes, we can see that the main engines need to be overhauled at least every 3-4 years of normal use (or much sooner if high warp speeds are used regularly).

  • Interesting. In The Drumhead they were able to replace the dilithium chamber while in deep space after an accident. Presumably they would have also checked for stress fractures in the core surrounding that area. And then in Phatasms they are able to construct and install a new plasma conduit while dead in space.
    – Xantec
    Apr 4, 2014 at 19:52
  • @Xantec - I think these are theoretical rather than actual limits. If the plan was to simply sit in space, I suspect you could last a century or more. If your plan was to whizz along at warp 9 for 70 years, you'd need to refuel regularly, constantly replicate parts and improvise solutions to servicing problems, etc
    – Valorum
    Apr 4, 2014 at 20:12
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    @Richard Ah, then we'd have Voyager, that can perform major structural repairs without a space dock in deep space.
    – Xantec
    Apr 4, 2014 at 20:25
  • @Xantec: In The Drumhead, it was specifically the hatch cover, not the entire chamber.
    – T.J.L.
    Jun 30, 2015 at 15:39
  • Given the level of fabrication technology and some half-remembered references, I'd guess that 7 years is what they can handle if they use their Bussard collector to gather interstellar hydrogen, and regenerate their own antimatter supplies (a very lossy process at such a small scale I'm sure) with a maintenance schedule of 3 years to keep a buffer against Voyager-like accidents. If allowed to stay in one place, I'd think that, between the replicator and the holodeck, they could probably build their own base given a sufficient supply of raw materials and a star to skim for deuterium.
    – Perkins
    Oct 2, 2015 at 23:39

The ship is constantly being "serviced" by it's engineering crew whether the ships in mission or in a friendly port or starbase. The time frame between overhauls is a matter of stress and the life expectancy of certain hardware. Anything that can be replicated or fabricated by the ship itself usually has spare parts stored in the ships cargo bays. Whatever cant be replicated or requires a certain degree of labor is done at a starbase or drydock; whatever those parts are is usually built to a standard long enough it might take years. The TNG Tecnical manual says that refits will occur every twenty years.


The ship is constantly being "serviced" by it's crew. The time frame between overhauls and essential upgrades is a matter of stress an life expectancy of certain hardware or demand by command. But in reality of the situation, with replicators and overhauls at starbases/drydocks, the ship should have an infinite shelf life. It's the old Ship of Theseus argument, a metaphysical question. If you replace every part of a ship over time is it still the same ship, in their case the matter used in it's construction could be reused in it's refurbishment; so in essense the ship could be kept in a state of permanent pristine condition.

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    You're aware you can edit your own answers right instead of posting a slightly altered version?
    – TheLethalCarrot
    May 1, 2020 at 8:39
  • Also this (and your answer below) don't address the question of how long it had to go between trips to starbases. We know that there's procedures (baryon sweeps, for example) that can't be performed by the crew.
    – Valorum
    May 1, 2020 at 12:19

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