The Tau'ri Fleet includes all Earth-built space vessels, as well as those acquired from ally and enemy races. These ships not only serve as a means of defending Earth from various alien threats, such as the Goa'uld, Lucian Alliance, and Wraith, but also as a means of transportation to planets not accessible by Stargate. Furthermore, these ships render assistance as needed to SG teams, including Stargate Command's flagship team, SG-1, and the Atlantis Expedition's flagship team, First Atlantis Reconnaissance Team or "AR-1" in both the Milky Way and Pegasus galaxies, respectively.