The introduction of the spore drive inStar Trek: Discoverysent ripples through the franchise, with one of the many questions raised being whyStar Trek: Voyagerhappened at all - but there is a convincing explanation.The USS Discovery’s spore driveallowed the ship to travel in an unprecedented manner, but the show’s place in theStar Trektimelinecreated problems.
Initially set in the era between theend ofStar Trek: Enterprise’s divisive finaleandStar Trek: The Original Series' first episode,Star Trek: Discoverymade several compelling (but risky) additions to franchise canon. WhileDiscoverymadeStar Trekbetter in a lot of ways, it also made contributions that were arguably a little too bold.

That said, I don’t think the spore drive falls into the latter category. It’s certainly a bit of a stretch to justify the retroactive invention of spore drive tech long before 24th-century shows likeStar Trek: Voyager, butDiscoverydoes just enough to make sure the entire scenario isn’t completely nonsensical.
The USS Voyager Would Have Benefited The Most From Discovery’s Spore Drive Technology
Every season ofStar Trek: Voyagerchronicles the show’s titular ship’s long and perilous journey through the Delta Quadrant in an attempt to return to Earth.Voyager’s unique premise opened up countless avenues for Captain Janeway (Kate Mulgrew) and her crew to explore a region of space that was largely uncharted at the time.
The USS Voyager managed to complete its journey in just seven years, although it would have taken decades if various shortcuts hadn’t been discovered along the way. However, of all the ways Janeway’s crew was able to shave time off the voyage, Starfleet’s long-classified spore drive tech wasn’t one of them.

WhenVoyageroriginally aired,Star Trek: Discoverywas still decades away from even being conceived, so there was no possible way the writers could have folded in the spore drive to help Janeway’s crew get home. That said, it now can’t be ignored that the technology did canonically exist at the time, even if only retroactively.
IfStar Trek: Voyagerhad been written today, it would have been possible to include a storyline that saw the crew unearth Discovery’s classified tech. Doing so would mean Captain Janeway simply declaring a black alert and getting her ship home in the blink of an eye. Unfortunately, for various reasons, that didn’t happen.

Why Star Trek: Discovery’s Spore Drive Would Have Created A Problem For Voyager
Stamets Was The Only One Consistently Capable Of Navigating The Mycelial Network
Whenthe USS Discovery jumped to the 32nd century, Starfleet suppressed all knowledge of the ship and its game-changing spore drive. It became intensely classified, which explains why tech is never mentioned in other shows. However, Starfleet would surely have made an exception when trying to get Voyager home.
On the other hand, when Janeway’s ship starts to reestablish contact with Starfleet, there’s a more obvious in-universe explanation for why the USS Discovery’s spore drive blueprints were never shared with Voyager’s crew. In short, it all comes down to how the ship would be piloted through the mycelial network.

Discovery was the only ship to ever have a working spore drive fitted, and even with the tech’s inventor on board, Lt. Commander Paul Stamets (Anthony Rapp), a suitable replacement was never found for the requirement to use a tardigrade when traversing the mycelial network.
Stamets himself became the primary method of using the spore drive, but it required genetic engineering for him to be able to do so, and the process remained experimental and highly dangerous. So, even if Starfleet Command did share the blueprints for the spore drive hardware, Voyager would have lacked an ethical and safe way to use it.

It is possible thatJeri Ryan’s Seven of Ninecould have assisted in finding an alternate way to access the mycelial network without a tardigrade or tardigrade hybrid. Seven’s use of Borg tech to upgrade some of Voyager’s systems helped the ship perform at unexpected levels. That said, combining Borg tech with the spore drive could have been especially dangerous.
Star Trek: Discovery Explained Why Voyager Could Never Have A Spore Drive
The First Modern Star Trek Show Toyed With Canon, But Didn’t Break It
While there’s admittedly a level of conjecture when trying to provide a solid canon reason why Voyager couldn’t or didn’t use spore drive tech to get home,Star Trek: Discoverydoes provide enough sound logic for things to make sense. Classifying the spore drive tech, while arguably a little convenient, does at least explain why it’s absent from otherStar Trekshows.
Plus, the tech never even makes it off Discovery, keeping the ship unique in its ability to traverse the galaxy so quickly.Stamets never successfully replicated his achievement on any other vesselin either the 23rd or 32nd century. While the USS Glenn was fitted with a spore drive, its lone attempt to use it resulted in the ship’s destruction.
So, the delicate and specific nature of Discovery’s spore drive, paired with the immense risks and ethical concerns, all combine to account for the lack of technology on the USS Voyager and other Starfleet ships. Therefore,Star Trek: Discovery’s coy writing meansStar Trek: Voyager’s storyline remains logical and intact.
Star Trek: Voyager
Cast
In this sci-fi series, the starship Voyager becomes stranded in the Delta Quadrant, 70,000 light-years from Earth. The diverse crew, led by Captain Janeway, embarks on a perilous journey home, encountering unfamiliar species and challenges while adhering to Federation principles in uncharted space.
Star Trek: Discovery
Star Trek: Discovery is an entry in the legendary Sci-Fi franchise, set ten years before the original Star Trek series events. The show centers around Commander Michael Burnham, assigned to the USS Discovery, where the crew attempts to prevent a Klingon war while traveling through the vast reaches of space.