Hydrogen ready to be used as a fuel or to produce water at a refinery.
Hydrogen is a fuel used by rockets, fighters, spaceships, starships and stations. Hydrogen is produced at a refinery, either extracted from a sufficiently dense atmosphere, or extracted from water, which also produces Air. This reaction can also be performed in reverse to create water from Hydrogen and Air. 1 unit is a full tank for fighters and rockets, the amount needed for a full tank and how long that tank lasts is determined by the design specifications of a spacecraft.
Power is required to produce Hydrogen.