Castillo Research Base was one of the first facilities set up study the outer planets, in this case Jupiter. Originally called Callisto, it was renamed after Ming the Merciless' favourite horse on his accession to Emperor. Since his fall there have been a number of attempts to return its name to the original form, but none of them have been successful.

Over the years since its founding the research base has expanded the range of its research, and a number of its discoveries have proved to be commercially successfully. As a result it produces a limited number of hi-tech commodities and, of course, imports those things which it is unable manufacture itself.

The base itself is of little interest to space tourists, the research instruments all being remote from the base. In spite of this the exchange draws a respectable number of traders, and most spacefaring citizens will visit it at some stage of their career.