The Earth Federal Forces are the military arm of the Earth Federation Government. Like a modern-day military they're divided into several branches, the most often-seen one being the "spacy" or space force. The space force is is sometimes identified in the animation as U.N.T. Spacy, but the Sunrise animation studio has now officially determined this organization's name as being the Earth Federation Space Force.
During the One Year War, the Federal Forces are headquartered in the underground fortress of Jaburo, constructed in a labyrinth of natural caves in South America. With its location a closely-guarded military secret, and protected by its subterranean location, Jaburo proves itself nearly invulnerable to enemy attack. This fortress is also a mighty manufacturing base, whose mobile suit factories and spaceship docks are used to rebuild the ravaged Federal Forces. However, within a few years of the war the Federal Forces have moved their operations elsewhere, and Jaburo has been relegated to a mere supply base.
The Federal Forces' other key stronghold during the One Year War is the asteroid fortress Luna II. Originally known as Juno, in UC 0045 this 180 kilometer-wide asteroid is moved from the asteroid belt into Earth orbit, where it becomes a mobile mine for colony construction. In UC 0060, with colony construction halted and tensions rising between the Federation and the space colonies, Luna II is converted into a military base.
In UC 0070, Luna II is moved to its final location at Lagrange point 3 to support the construction of the Side 7 colony. Since this puts it at maximum distance from the Principality of Zeon, the moon, and the other space colonies, its strategic significance is pretty slight. However, as the Federal Forces' only surviving space outpost, Luna II proves a valuable staging area for the Federal Forces during the last days of the war. Though its manufacturing capacity is small compared to that of Jaburo, it also contributes some quantities of warships and mobile suits to the Federal Forces' arsenal. After the war, Luna II remains in use as a military base until it is raided by the Neo Zeon in UC 0093.
During the last days of the One Year War, the resurgent Federal Forces succeed in capturing the Principality of Zeon's asteroid fortress of Solomon. Now renamed Konpei Island, the captured fortress serves as a staging area for the Federal Forces' final push into the enemy's homeland. Due to its prime location near Side 1, Konpei Island becomes the primary space headquarters of the Federal Forces after the war... at least until a disastrous attack on the Federal Forces' naval review in UC 0083.