In the TV series “The Expanse”, the Outer Planets Alliance (OPA) is a loosely affiliated network associating under a common ideology, fighting for the interests of inhabitants of the Belt. The OPA started its life as a labor union and advocacy group, often in direct conflict with the inner planets’ Earth-Mars Coalition Navy. Its logo is a split circle and distinct factions have cells based at every station in the Belt — including two major groups at Tycho Station and Ceres Station.
The OPA is described as either a sociopolitical movement, according to people sympathizing with the Belters, or a terrorist network, according to the inner planets. Its decentralized structure and the range of activities by groups claiming affiliation negates the assertion that it has a headquarters. It is often in contention with the MCRN — Martian Congressional Republic Navy.
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