In A.C. 193, the satellite was being used as a forced labor camp by the United Earth Sphere Alliance. Among the miners forced to work there was Instructor H. The Maganac Corps, intending to free the miners, hijacked Quatre Raberba Winner's shuttle and took him hostage, demanding the release of the miners in exchange for Quatre's safety. However, a traitor within the Corps informed the Alliance, and the satellite was soon surrounded by the Alliance space forces. The Corps were outnumbered three-to-one, and Rashid Kurama, their leader, had been wounded by the traitor. However, Quatre, after some convincing by Instructor H, volunteered to assist them. He joined the Corps in battle, piloting Rashid's customized Maganac. Thanks to Quatre's leadership, the Maganac Corps managed to destroy three-quarters of the enemy Leos, allowing the shuttles carrying the miners to escape unharmed.
By A.C. 196, the satellite has been abandoned after its resources have been depleted. Years of mining has deformed it to the point where it is no longer spherical. However, its close proximity to Earth made it an essential part of Dekim Barton's version of Operation Meteor. He misdirected the Preventers using Mobile Dolls, and secretly transported the real invasion force: hundreds of MMS-01 Serpent Mobile Suits, into the satellite, intending to send them to Earth.
However, Dekim's plan was interrupted by Zechs Merquise, piloting the OZ-00MS2B Tallgeese III, who destroyed two Serpent carriers and demanded Dekim to surrender. However, Dekim threatened to drop X-18999 if Zechs destroys any more carriers, forcing him to watch helplessly as hundreds of Serpents descended upon Earth. Upon learning that the colony drop has been averted, Zechs immediately fired his Mega Beam Cannon at MO-III, obliterating it. However, he was too late to stop Dekim from escaping.