Voyager's holographic Doctor (Robert Picardo) transmits his program to the Alpha Quadrant using an abandoned Hirogen subspace relay station. After fending off a Romulan plot aboard the experimental USS Prometheus, the Doctor gets in touch with Starfleet Command, who promise they'll do all they can to bring Voyager back home.

Captain Benjamin Sisko's (Avery Brooks) USS Defiant crew takes a break from active combat in Star Trek: Deep Space Nine season 6, episode 14, "One Little Ship", when they're assigned to investigate a subspace compression anomaly that shrinks anything it comes in with. Lt. Commander Jadzia Dax (Terry Farrell), Dr. Julian Bashir (Alexander Siddig), and Chief Miles O'Brien (Colm Meaney) send a runabout into the anomaly, to study the principles behind its spatial distortion. Theoretically, understanding how the anomaly shrinks things could also help Starfleet create transwarp corridors, which would give the Federation a tactical advantage against the Dominion.

Star Trek: DS9 Could Have Saved The USS Voyager

The USS Defiant Helped Starfleet Research Transwarp Corridors

Star Trek: Deep Space Nine could have saved the USS Voyager if the USS Defiant's research into the subspace compression anomaly had actually led to Starfleet being able to create transwarp corridors. DS9's "One Little Ship" aired just a month after Star Trek: Voyager's "Message in a Bottle", so Starfleet already knew that Voyager was lost in the Delta Quadrant, and was actively researching ways to bring them home. While Captain Sisko is told that creating transwarp corridors will help Starfleet beat the Dominion, bying Star Trek's warp speed limit would also bring the USS Voyager home quickly.

The USS Voyager's predicament doesn't have to be specifically mentioned in Star Trek: Deep Space Nine for the Defiant's scientific mission to relate back to Star Trek: Voyager. Starfleet's promise to recover Captain Kathryn Janeway's (Kate Mulgrew) lost starship only matters to the USS Voyager crew's loved ones or officers involved in bringing Voyager back, like Star Trek: The Next Generation's Lieutenant Reginald Barclay (Dwight Schultz).

Instead, Sisko's orders realistically reference Starfleet gaining a tactical advantage over the Dominion instead of Voyager's Project Pathfinder, which keeps Captain Sisko—and DS9's ongoing storyline—singularly focused on the Dominion War.

Star Trek: DS9's Plan To Bring The USS Voyager Home Never Would Have Worked

DS9's Stealth Crossover Had The Key To Ending Star Trek: Voyager Early

Star Trek: Deep Space Nine's plan to bring the USS Voyager home from the Delta Quadrant has merit, but it wouldn't have worked. In "One Little Ship", the Jem'Hadar attack the USS Defiant, leaving Dax, Bashir, and O'Brien responsible for saving their compatriots. The DS9 episode's drama comes from the tiny runabout cleverly foiling the full-sized Jem'Hadar, which can't happen if DS9's subspace compression research is actually successful. The Defiant's success in DS9 season 6 also would have meant the end of Star Trek: Voyager after only 4 seasons, and Voyager's best years were still to come.

In Star Trek: Lower Decks season 5, episode x, "title", the tiny Intrepid-class USS Endeavor shows what could have happened to the USS Voyager if Starfleet had been able to bring Janeway's crew back home using Deep Space Nine's research in "One Little Ship".

With this pair of 1998 episodes, Star Trek pulled off a seemingly impossible stealth crossover between Star Trek: Deep Space Nine and Star Trek: Voyager. The Doctor's visit to the Alpha Quadrant in Voyager's "Message in a Bottle" reveals DS9's updated Starfleet uniform on the EMH Mark 2 (Andy Dick)—and more pressing news about the Federation's war with the Dominion.

At the same time, DS9's "One Little Ship" shows how the USS Voyager's with Starfleet Command hasn't gone ignored, because Star Trek: Deep Space Nine is unknowingly researching a way to bring the USS Voyager back home.