They thrive in water, but adapted to be able to withstand dry periods by desiccating and stopping their metabolism (you could say their life is suspended, really) and resuming when water returns.
In their dry state (anhydrobiosis&#x2F;cryptobiosis) there&#x27;s not really anything that would violently evaporate in a vacuum and thus destroy cell structure, like there is in live cells, and they repair DNA damage after they rehydrate, so they&#x27;re not harmed much by vacuum or ionizing radiation.