Starfleet is a fictional organization in the Star Trek media franchise. Within this fictional universe, Starfleet is a uniformed space force maintained by the United Federation of Planets as the principal means for conducting deep space exploration, research, defense, peacekeeping, and diplomacy. While most of Starfleet's members are human and it has been headquartered on Earth, hundreds of other species are also represented. Most of the franchise's protagonists are Starfleet commissioned officers.