Hydrogen
From Galactic Fleets Wiki
Hydrogen is the fuel used for light-speed travel within a system.
Hydrogen can be obtained by refueling from a H Platform or by clicking on your ship name and inputing the amount of turns used to refuel from space. Refueling from space depends on the hydrogen density.
Hydrogen Density Ranges:
Minimimal (Planetary System) - Very Low - Low - Medium Low - Medium - Medium High - High - Very High - Optimal