United Earth Starfleet

The United Earth Starfleet, often known simply as Starfleet, was the space agency of United Earth in the mid-22nd Century, prior to the formation of the United Federation of Planets. The Federation Starfleet later developed out of the United Earth Starfleet and its Vulcan, Andorian, Tellarite, and Alpha Centauri counterparts, even adopting the agency's name. The United Earth Starfleet launched Enterprise NX-01 and later Columbia NX-02; the former was largely responsible for establishing United Earth as a legitimate interstellar power and paving the way for the founding of the Federation. Admiral Maxwell Forrest was the commanding officer until his death in 2155 on Vulcan; he was succeeded by Admiral Gardner.

Unlike its future incarnation, the Earth Starfleet was not a military organization, but rather was purely scientific and exploratory in its mission. MACOs fulfilled any military functions needed aboard Earth Starfleet vessels.