Liquid Hydrogen

Liquid Hydrogen is a very cold liquid element obtained by cooling Hydrogen Gas below its condensation point. Producing it is one of the late-game thermal challenges, because its freezing point and boiling point are only a few degrees apart, leaving very little room for error when trying to keep it stable as a liquid.

In the base game, Liquid Hydrogen can be harvested from space on helium giant worlds. In Spaced Out!, it can also be obtained from renewable space points of interest in Metallic Asteroid Fields, where it regenerates at 67.5–202.5 kg per cycle. Another source reports a regeneration rate of 132–165 kg per cycle for one of these space deposits.

Because of how close its phase-change temperatures are, safely cooling Hydrogen Gas into Liquid Hydrogen is difficult and usually requires very precise temperature control. This makes it a late-game material rather than a routine industrial fluid.