there is a part that joins the axles of the satellite cogs, that part is moving in the same direction of the sun gear, and the ring gear is fixed. Anyway, like all planetary gearset, it contains clutches and brakes, that either fix one element or connect the input-output to different parts (the sun, the planet carrier, the ring gear), and so on

check this link: http://en.wikipedia.org/wiki/Epicyclic_gearing