Tardigrades can survive the vacuum of space by turning into glass
Animals
Tardigrades can survive the lethal environment of outer space by entering a state of cryptobiosis, where they replace the water in their cells with a biological glass.
Tardigrades, or 'water bears,' are 0.5-millimeter-long extremophiles capable of surviving conditions that would destroy any other animal. When faced with extreme heat, cold, or desiccation, they enter a 'tun' state, reducing their water content to just 1% and replacing it with a sugar called trehalose. This process turns their internal cellular environment into a protective, glass-like solid that stabilizes proteins and DNA against damage.