Leviathan’s moons call to me!
I am imagining the Astrogation Temples, where you go to have your journey mapped. The mapping takes place in empty rooms with vaulted ceilings, where stone moon scultpures are put into motion on hard light holograms.
Why is it a temple? Because all journeys have religious significance. The navigators are trained in anthropological religious studies, helping humans keep in touch with their humanity while traversing the void. They might offer a parable or an argument or sit you down for a meal with a nearby family or offer guided meditation with their coordinates.
Astrogation computers are available but only used in an emergency. Computers have a rough time around Leviathan. The gas giant’s magnetic radiation wreaks havoc with any complicated computer and A.I. research is strictly forbidden because of the fell effects Leviathan’s pull has on synthetic entities of any kind.
The Ducal Moons are held by the 4 Major Houses: Job, Triton, Rangomai and Mizuchi. In the centuries since their settling, the moons have changed hands a number of times with houses Major and Minor rising and falling on a political tide.
Baikonur was the first moon settled and is held in trust by the Unions and Temple. The Major Houses take turns guarding it, changing every 4 cycles. Baikonur, because of its special place in the orbits, was named for a spaceport on Olde Earth, rather than a nautical port.