Illion sole purpose was to be a backup plan in case Star Access One would experience a catastrophic failure, but after a group of crew members deflected from Star Access One, Illion became the stronghold of the people now called "Renegades". Because Illion was intended to be the backup of Star Access One, while it's samller it still features most of modular factories that SAO has and so it can almost do everything SAO can, besides the offensive capabilities. Illion though has better defensive armament and modules than SAO because as a backup plan it was concieved to be the last resort of humans to survive who could also be under attack by other violent species or enemies.