In 2007, a little-known creature called the Tardigrade became the first terrestrial organism that survived in open space. This research was conducted aboard the Foton-M3 satellite, the launch of which was sponsored by the European Space Agency. The purpose of the experiment was to find out how terrestrial organisms endure the extreme conditions of cosmic radiation at the molecular level. The result exceeded all expectations: the Tardigrade endured the short-term effects of extremely low temperatures, cosmic radiation and an almost complete vacuum.
Tardigrades (lat. Tardigrada) are widespread throughout the Earth, they could be found in the sea, freshwater ponds and on land. Their body is less than 1 mm long and they look like bears, although biologically they are very primitive organisms.
Over millions of years of evolution, the Tardigrades have learned to hibernate in adverse conditions, when almost all the functions of their vital activity are suspended. This condition is called cryptobiosis. It is believed that this ability allows Tardigrades to survive in outer space.
X-ray resistance is a side effect of the Tardigrades adaptation to dehydration. According to scientists, severe dehydration causes damage to living organisms at the molecular level, it can even break the DNA chain, as X-rays do. Scientists began exploring the capabilities of the Tardigrade using the genome sequencing of the Ramazzottius varieornatus Tardigrades species, whose cells are particularly resistant to external influences. As a result, it was found that a protein known as Dsup prevents the destruction of the DNA. It allows the Tardigrade to get through dehydration and radiation. Scientists have also found that human cells with the Tardigrade DNA elements can reduce the damage from x-rays by about 40%. Thus, on the basis of research, it is possible to develop mechanisms for protecting people from X-rays while undergoing treatment or under extreme conditions, including a long space flight.
The study of Tardigrades is actively continues. Scientists believe that the Tardigrade is the key to understanding of how earth life in general adapts to the conditions of a long stay in outer space.