Large enough that it could almost have formed the nucleus of a protostar in its own right, Jupiter’s massive size makes the Jovian System one of the most challenging places in the system to colonize. Jupiter’s powerful magnetic field means that its inner moons — and the outer ones, when their orbits pass through its
immense magnetotail — are bombarded with enough ionizing radiation to kill transhumans not protected by the heaviest of shielding within a matter of hours.
Jupiter’s powerful gravity well is a major hindrance to gas mining in the planet’s atmosphere, as even craft that do not succumb to the violent, centuries-long atmospheric storms can achieve escape velocity with only the most powerful propulsion systems. Given the need for heavy shielding on such craft, gas mining on
Jupiter is not nearly as efficient as on Saturn. Jupiter has a tenuous ring system, much less dense than Saturn’s, which extends out for 20,000 kilometers around the planet, encompassing the orbits of its two closest moonlets.
However, Jupiter’s gravity is also a valuable resource. Craft bound for Saturn and beyond can slingshot themselves outward by circling the planet to pick up velocity, cutting months or years off their trips. The heavily militarized Jovian Republic levies tolls against all spacecraft using Jupiter’s gravity to pick up velocity, including asteroids under propulsion. This protection money is the Junta’s primary source of revenue. Planetary Consortium ships generally accept the payment as part of operating expenses. Other factions are not so cooperative, and the Junta regularly seizes or destroys blockade runners.
Most of Jupiter’s moons are really captured asteroids, lacking the size and geological complexity of planetary bodies. All are occupied. Some were converted to habitats; others host only Junta military and mining outposts. The Jovian moonlets consist mostly of carbonaceous rock, poor in metal, with some of the larger moonlets having layers or even cores of ice. Beehive habitats and Reagan cylinders predominate in the Jovian system. Reagan cylinders (called “sarcophagus habs” by every other faction) are an inefficient variation on the O’Neill cylinder in which excavators hollow out an immense, cylindrical cavern in a rocky asteroid and then alter the asteroid’s rotation with external thrusters to simulate gravity. Other habitat types are rare in Jovian orbit, especially within 2 million kilometers of the planet, where the radiation is strongest.
For a bioconservative faction unwilling to adopt radiation-resistant morphs, the Junta is in a poor location. Shielding their populace beneath tons of rock is a necessity. Despite its military hegemony, the Junta can’t control all of Jovian space, and there are things it can’t do on its own — like exploring Europa. A number of unaligned habitats and surface settlements exist in the ring system and the orbits of the Galilean moons.
The Jovian Republic has renamed Jupiter’s moons after various neo-conservative heroes from Earth’s history. From closest to most distant, the moonlets are Metis (Bush), Adrastea (Fairway), Amalthea (Solano), Thebe (McAllen), Leda (Chung), Himalia (Pinochet), Lysithea (Friedman), Elara (Buckley), Ananke (Nixon), Carme (Kissinger), Pasiphae (Schilling), and Sinope (Garcia). All are tiny, between 5 and 100 kilometers in diameter.