Tuvok

Tuvok, a Vulcan character played by Tim Russ, was Voyager's head of security.

The Star Trek: Voyager episode "Flashback" gives his first Starfleet assignment as an ensign aboard the USS Excelsior under the command of Hikaru Sulu (concurrently with the film Star Trek VI: The Undiscovered Country) during the Khitomer Incident. He left Starfleet soon afterward and underwent the Kolinahr ceremony on Vulcan to purge his emotions. Several decades later, he re-enlisted in Starfleet and served aboard the USS Wyoming and then came aboard the Intrepid-class starship USS Voyager as a lieutenant commander. In the late 2360s, Tuvok was assigned to infiltrate the Maquis organization aboard Chakotay's Maquis ship. During this infiltration, both the Maquis ship and the Starship Voyager were transported to the Delta Quadrant. The Maquis ship was destroyed and the two crews were forced to work together on Voyager.

He arrived with the Voyager crew seven years later and was reunited with his wife and son on Vulcan.