Waterbears survive in the vacuum of outer space

[NoXion]

Someone mentioned that investigating the tardigrade further could prove useful for improving the survivability of astronauts. But I wonder; how much of this creature's hardiness is due to its small size? Being a much simpler organism than humans, there are fewer things to go wrong. A smaller cross-section means less radiation exposure, that sort of thing.

 

[Jonti]

From How Does the Tiny Waterbear Survive in Outer Space? | Science | Smithsonian

It turns out that the adaptation that allows tardigrades to live through these trying conditions is their ability to enter a dehydrated state that closely resembles death. When encountering environmental stresses, a tardigrade curls up into a dry, lifeless ball called a tun, reducing its metabolic activity to as low as .01 percent of normal levels. In order to do so, tardigrades produce trehalose, a special protective sugar that forms a gel-like medium that suspends and preserves the organelles and membranes that make up the animal’s cells.

They also have sophisticated DNA protection and repair abilities (from Tardigrade protein helps human DNA withstand radiation)

Kunieda and his colleagues discovered that a protein known as Dsup prevented the animal's DNA from breaking under the stress of radiation and desiccation. And they also found that the tardigrade-tinged human cells were able to suppress X-ray induced damage by about 40%.

Waterbears have active mechanisms to resist and repair cellular and genetic damage. It seems that the astounding survival abilities of waterbears come from specific adaptations rather than just being a side effect of being tiny.

 

[NoXion]

Well that is very interesting. I do still wonder what difficulties would be involved in scaling this up and applying it to humans.

Also, could such a thing be applicable to humans already born? I've heard that modified or artificial retroviruses could be used to genetically modify somatic cells, although I might be misremembering.

If not, then this lifting of useful traits from water bears might be more useful for those intending to establish permanent extraterrestrial settlements, where being born with the ability to better resist radiation damage and/or go into a hibernative state would be extremely useful.

A fix for bone and muscle wastage in microgravity would also be helpful, eliminating the costs involved in producing pseudogravity via centrifugal force.