Tardigrades can survive the vacuum of space by turning their cells into biological glass.

Tardigrades are microscopic invertebrates that utilize a survival strategy known as anhydrobiosis to survive extreme desiccation. During this process, they produce unique proteins called Tardigrade-Disordered Proteins (TDPs). These proteins lack a fixed three-dimensional structure under normal conditions but form a rigid, glass-like matrix when the animal dries out. This biological glass preserves the delicate structures of the cell, such as proteins and membranes, preventing them from breaking or tangling. In 2007, the European Space Agency's FOTON-M3 mission proved that tardigrades could survive ten days of direct exposure to the vacuum and solar radiation of low Earth orbit. Upon returning to Earth and being rehydrated, many of the specimens successfully revived and even laid eggs. Research published in the journal 'Molecular Cell' in 2017 confirmed that TDPs are essential for this glass-like transition. Without these specific genes, tardigrades lose their legendary resilience to drying. This glass-like state, or 'tun,' allows them to survive temperatures as low as -272 degrees Celsius and pressures six times greater than those found in the deepest ocean trenches.