How do tardigrades survive the vacuum of outer space?

The answer

Tardigrades, eight-legged micro-animals barely 0.5 mm long, can survive the vacuum of space by entering cryptobiosis - a state where metabolism drops to nearly 0.01% of normal. They produce a unique protein called Dsup (Damage Suppressor), discovered in 2016 by University of Tokyo researchers, which shields their DNA from radiation. During a 2007 ESA experiment aboard the FOTON-M3 satellite, tardigrades survived 10 days of direct space exposure, enduring UV radiation over 1,000 times lethal human doses. They also replace cellular water with trehalose sugar, forming a glass-like matrix that preserves cell structures until rehydration restores full biological function.