By default, Orbiter 2010 does not have any bases on the moons of Jupiter, Saturn, Uranus, or Neptune. This very basic add-on simply puts a copy of Brighton Beach on each of the moons of Jupiter so that you have some kind of target to aim for when traveling to the Jovian system.
The base locations were carefully chosen to offer the best view of Jupiter while landed at the base. All 4 of Jupiter's moons are tidally locked, so you will have a nice view of Jupiter from these base locations no matter what month or year you happen to be visiting.
Since these bases are just a copy of Brighton Beach, there are no additional textures or mesh files in this add-on.