150 years before AG Year 115, the Earth Federation initiated a plan to colonize Mars in a plan called "Mars' Birthday" in order to ease the burden placed on Earth's carrying capacity. Due to the appearance of the fatal disease "Mars Ray", 20% of the colonists fell ill. For reasons unexplained, the Earth Federation opted to abandon the colonists in lieu of rescuing them. Instead, they opted to cover it up, while stating in the official report that the disease wiped out all of the colonists. In truth, a significant portion survived and established a new civilization calling itself Vagan. The Vagan home nation is located in Second Moon, which orbits Mars. Both the Vagan mobile suit and ship technology was obtained from a part of EXA-DB, a large weapons database from the Colony Nation Wars