The Galaxy Federation are the main protagonists of the Thunder Force series. As an extraterrestrial superpower, the Federation is on a constant war against the evil ORN Empire.
As the Federation constantly struggles in the war against the ORN Empire's large fleets, the Federation decided to take on an alternative method of defense by constructing a series of starfighters known as the "Fire LEO" as a plan known as "Project Thunder Force". With these fighters, the Federation was able to gain the upper hand numerous times by allowing the small, yet formidable fighters to deal heavy blows against the ORN Empire's centers of command, such as the bio-computer Khaos.
In Thunder Force VI, the Federation received military aid from Earth, in the form of a powerful prototype aerospace fighter deployed in response to the Federation's call for help. The two forces then form an alliance to defeat the ORN Empire and to stop the imminent invasion of Earth. The Federation forces then offered to accompany the prototype fighter on the latter's journey back to mankind's home planet, presumably to enact formal contact as recommended by the original Rynex team.