Simple mod to refill fuel in runtime.
Go to releases and download RefillMod.zip. Once download, put RefillMod.zip into MODS folder in Spaceflight Simulator_Data and unzip. You can found Spaceflight Simulator_Data in folder where you install steam in the nex path: Steam\steamapps\common\Spaceflight Simulator\Spaceflight Simulator Game\Spaceflight Simulator_Data. Finally, execute game normaly.
When you are playing, press O to reload your tanks.