What became of the Kelvan technology in Star Trek TOS "By Any Other Name"?

Question

I just watched the TOS episode By Any Other Name in which the Kelvan invaders (easily) modified the warp engines of the Enterprise in order to fly from this galaxy to the Andromeda galaxy (2.537 million light years) in under 300 years. In the episode it was noted how much more advanced this technology was.

At the end of the episode the Enterprise turns around and heads for home. But what happened to all that advanced technology? How come the Enterprise post this episode continued to fly around at "normal" warp speeds?

Answer 1

Frankly, an out of universe answer may be most applicable here.

With few exceptions, in terms of actual in-universe consistency (barring Stardates of course) you can generally watch TOS episodes in any order. The thing to remember with TOS is that it wasn't intended to maintain an arc or generally even minute consistency from one episode to the next (except in broader beats). It has been said that TOS has no memory from episode to episode - unlike later series, TOS was meant to be an anthology show or little morality tales set with the same characters and settings. Additionally, apart from production staff like Robert Justman, Dorthy Fontana, Gene Coon, and Roddenberry polishing and modifying scripts, each episode had different writers that may not have been familiar with previous episodes. Scripts were often selected as to what to produce and air next, not on a story basis but in terms of time and cost and simply if the script was ready to go or not.

TL:DR - because Jerome Bixby (story for By Any Other Name) didn't write the next story (Return to Tomorrow - John T. Dugan) and nobody bothered to worry about what happened in the previous episodes generally from a broader, overarching storyline perspective

• source: paraphrasing and analysis from reading Marc Cushman's "These Are the Voyages, Series 1 and Series 2 production background books)

Answer 2

You could interpret it as the Kelvans removing the technology once they are safe, following their own version of the prime directive. Sudden introduction of intergalactic travel would undoubtedly tilt the balance of power in the galaxy, and in the end could end up affecting the neighbors.

Answer 3

My guess would be the Roman's laptop. Sure, he knows what it is and what it does, and can even be instructed in its use, but he will never be able to even grasp the fundamental concepts behind its construction.

Similarly, the Federation has this technology, and knows what it does, but its technology is simply far too advanced to replicate. The Federation, though, being what it is, might have been able to confirm one or two of their already existing hypotheses, which advanced them enough to develop the transwarp drive.

Answer 4

The technology would have been removed from the Enterprise for reverse engineering by Starfleet, and eventual inclusion in future starships. Hence the Excelsior had "Transwarp" drive in Star Trek III: The Search for Spock. But some of the more easily analyzed technology might have remained aboard the Enterprise (especially if it would have been difficult to uninstall it). Hence the Enterprise would be reinforced to withstand high warp speeds, up to over Warp 14 ("That Which Survives").

Answer 5

Rojan may have agreed to the technology being used for the robot probe, but insisted that it not be studied by Starfleet due to the risk of destabilizing the Milky Way galaxy's political status. Another possibility was that once the robot probe reaches the Kelvan Empire, the Kelvans might react angrily to Rojan's betrayal and use even newer technology to send a follow-up mission in considerably less time than 300 years, and they might expect Rojan may have shared Kelvan technology with local species. Independently-developed technology of the Federation and others would be less likely to be penetrated by Kelvan "infiltrative" technology.

I also wonder WHAT the Kelvan drive is that could achieve Warp 19.3 and maintain it for 300 years of continuous operation, as well as what they used for fuel? Bussard collection of ionized atoms in intergalactic space to fuel a slipstream drive?