When a SpaceX rocket, embarking on the 22nd cargo resupply mission to the International Space Station (ISS), leaves Earth on 3 June, it will have a group of unlikely travellers in the form of tardigrades (also known as ‘water bears’ for their appearance under a microscope) and baby squid.
Although the bulk of the spacecraft’s cargo will be made up of supplies, technology demonstrations and scientific research experiments, around 5,000 tardigrades and 128 baby glow-in-the-dark bobtail squid will also be hitching a ride to, effectively, act as guinea pigs in a series of experiments NASA is conducting to better prepare astronauts for the rigours of space flight.
The International Space Station that lies in low-Earth orbit has, for several years now, served as a theatre for numerous experiments owing to its unique microgravity conditions. Since becoming operational in 1998, the ISS has become a symbol of the cooperation between the five participating space agencies of NASA (US), Roscosmos (Russia), JAXA (Japan), ESA (Europe) and CSA (Canada).
The $150 billion microgravity space laboratory has hosted over 3,000 research and educational investigations involving scientists from more than 100 countries carrying out cutting-edge research across various disciplines.
Why the tardigrades?
Although most commonly found in water, the microscopic animals, tardigrades, owing to their phenomenal physical resilience and unique biology, have quite literally been found everywhere. These little animals have been known to survive the most extreme conditions and it won’t even be the first time that they’ve been sent to space. In fact, there may be some already on the moon after a mission carrying a group of them crashed onto the lunar surface.
“Some of the things that tardigrades can survive include being dried out, being frozen and being heated up past the boiling point of water. They can survive thousands of times as much radiation as we can and they can go for days or weeks with little or no oxygen,” said Thomas Boothby, assistant professor of molecular biology at the University of Wyoming and principal investigator for Cell Science-04 tardigrade experiment at a press conference on Wednesday.
Having already sequenced the tardigrade genome, scientists are looking to study how environmental changes impact these creatures through their gene expression, and particularly how they respond to low-Earth orbit. This, researchers believe, could lubricate the formulation of adaptation and survival strategies for humans in highly stressful environments like space.
And the squid?
The Understanding Microgravity on Animal Microbe Interactions project, hilariously abbreviated to UMAMI and led by Jamie Foster, professor in the Department of Microbiology and Cell Science at the University of Florida, aims to provide insight into how beneficial microbes interact with animal tissue in space.
Our bodies are filled with several microbes that are important in maintaining physiological well-being, performing a number of key functions, especially in digestion and detoxification. When the balance of these microbes is disrupted, humans risk becoming susceptible to infection.
This is where the 3mm-long bobtail squid come into the picture. Scientists have picked these little critters for two specific reasons.
One, they have a unique light organ inside their bodies that can be colonised by a specific species of luminescent bacteria. The squid then uses this bacteria to glow in the dark. Since there is just a single type of bacteria and one specific type of host tissue, researchers are easily able to see how this process takes place. Secondly, the bobtail squid’s immune system resembles that of a human’s.
The squid are not born with the bacteria, with researchers seeking to introduce them into the animals during the experiment and monitor the interactions. Like the tardigrade experiment, researchers will map the molecular timeline of gene expression in the hope of learning how these microbes change in microgravity environments.
