Throughout the majority of the 24th century the starbase served as the command station for the First Fleet and all operations along the Neutral Zone.
In the 2370s she was under the command of Captain Elijah Groves.
In 2371 the USS Lionheart transported Fleet Admiral Edward Proudfoot Sr. to the station for negotiations with comand level officers of the Romulan Star Navy. During this time the USS Robinson was undergoing refits at the station. Also there were the Rabin, Ashanti and Bellepheron who's commanders took part in the negotations.
Fleet Admiral Elisa Keil (2371) - Commander of the First Fleet
Captain Elijah Jacobs (2370s) - Commander of Starbase 39-Sierra
Commander Doleo (2371) - Special Counter Intelligence Unit Commander
Lieutenant Carla Rhiems (2371) - Special Counter Intelligence Unit Team Member