Oh, sure, human astronauts will be on board Space Shuttle Endeavour’s STS-134 mission set to launch Monday. But so will five microscopic life forms: Water Bears, also known as Tardigrades (shown above); the bacteria Deinococcus radiodurans and Bacillus subtilis; and the archaea Haloarcula marismortui and Pyrococcus furiosus.
Water Bears (or Tardigrades)
Members of the animal kingdom, the Water Bears are “huge” microorganisms compared to the other LIFE travelers. Their bodies are composed of four segments, each with two legs ending in claws. Water bears are extremophiles, which means they can adapt to some pretty hostile environments — from 150 degrees Celsius (302 Fahrenheit or hot enough to bake biscotti) to just a few degrees above absolute zero. Plus, they’re radiation resistant.
The tardigrades had already been coaxed into an anhydrobiotic state, during which their metabolisms slow by a factor of 10,000. This allows them to survive vacuums, starvation, dessication and temperatures above 300 degrees Fahrenheit and below minus 240 degrees Fahrenheit.
Once in orbit, the tardigrade box popped open. Some were exposed to low-level cosmic radiation, and others to both cosmic and unfiltered solar radiation. All were exposed to the frigid vacuum of space…
Just how the invertebrate astronauts protected themselves “remains a mystery,” wrote the researchers.
… personally, I think it looks like something out of a Tim Burton movie….
Conan the Bacterium (common nickname for Deinococcus radiodurans or "terrifying berries")
This strain of bacteria is so hardy it has the nickname, Conan the Bacterium. Whereas 10 Gy (Grays) of radiation would kill an average human, Deinococcus radiodurans can survive a whopping 5000 (five thousand) Gy. More than a third of the cells will even survive a dose of 15,000 Gy! That’s an ideal trait for long journeys through the dangerous radiation of outer space.
The Average Joe of Bacteria (Bacillus subtilis)
Bacillus subtilis is a “model organism,” a standard bacteria used over and over again in many different biological experiments. tThe MW01 strain will fly on Shuttle LIFE. Bacillus subtilis is also quite radiation resistant and has a long history of space biology missions, going back to the days of Apollo. That will allow a good comparison point between Shuttle LIFE and some of the other space flights of this bacterium.
Poison Lover (Halomonadaceae sp. GFAJ-1)
These rod shaped bacteria from the family Halomonadaceae made headlines as the first known microorganisms that are apparently able to thrive and reproduce using the toxic chemical, arsenic. The bacteria appear to substitute arsenic for phosphorus in their cell components. If these results are confirmed, they may imply a separate biochemistry for life. And that means that life might arise in planetary conditions we never before thought suitable.
Old Salty (Haloarcula marismortui, an archaeon)
Many archaeons — a type of single-celled organism — are extremophiles that thrive under conditions that would destroy other organisms. Haloarcula marismortui lives in extremely salty environments. Why are we testing an organism that seems to enjoy high salinity? If ancient Mars had water on its surface at some point in the past, it was in all likelihood very salty and briny. Any life existed that there would probably have lived in those salty seas. It’s important to learn if such a salt-loving organism can survive a long journey through space.
Fire Eater (Pyrococcus furiosus, an archaeon)
These extremophiles love heat. Pyrococcus furiosus was discovered in 1986 in volcanically heated ocean sediments off the coast of Italy, and it thrives in temperatures between 70 and over 100 degrees Celsius (158 and 212 degrees Fahrenheit). But interplanetary space isn’t hot; nor is the surface of Mars or Phobos. So why send a heat-seeking extremophile on the journey? There is always the small risk that somewhere in processing the payload, some mistake would cause the payload to overheat. In that case, Pyrococcus furiosus will serve as a kind of temperature control. If it is the only LIFE organism to survive the trip, this will indicate that overheating rather than conditions in space caused the loss of the other organisms.