Ice Giant
Overview
Gas Giants are a type of planet in Dyson Sphere Program. They are (as the name suggests) giant worlds with no solid landmasses on their surface, instead being composed almost entirely of gases, primarily hydrogen and its isotopes. If Icarus flies onto a gas giant, it will not be able to land, and will be forced to fly around.
The aforementioned gaseous resources -- hydrogen, deuterium, and fire ice in the case of ice giants -- can be collected by Orbital Collectors (placed on the planet's equator), or manually, by 
Icarus.