Water Bears IN SPACE
Corinne Moore, Technical Business Development Associate
3 minute read
No, this is not the latest low-budget and/or sci-fi film; but wouldn’t that be neat? Originally discovered in 1773 by Johann August Ephraim Goeze, water bears are neither as cute nor as cuddly as the name suggests. This cuddly connotation is the common name for a creature called a tardigrade, which is a type of arthropod, like more common insects, spiders, and crabs. Water bears are microscopically small, < 1 mm, and are commonly found across our planet in wetlands, lakes, mountainous regions, rainforests, and even Antarctica. The term “water bear” was coined when their movement was observed to be similar to a bear lumbering about. So what do these cuddly little buggers have to do with space and what we do here at KMI? As you’ll see reading on, their ability to survive in suboptimal conditions is a hot topic in relation to a human space presence, which is the vital next step in our growth as a species.
SEM Micrograph of a tardigrade (AKA water bear)
These fascinating critters live for about 60 years and can thrive in many conditions that humans can’t, including extreme freezing and heat (-328 °F to 304 °F), environments deprived of oxygen and water, low vacuum pressure, high levels of radiation, and more! While there’s much we don’t understand about how they’re able to survive, we do know that their key to survival without water is entering a state called cryptobiosis, in which they essentially shut down and wait for a better day. When entering cryptobiosis, they curl into a ball-shaped form called a tun and shut down certain functions of their bodies, including metabolic processing, reproduction, and healing. Essentially, they slip into a coma and are preserved in time, rising from this state when conditions are more favorable. In 2016, scientists at Japan’s National Institute of Polar Research took this a step further and found they were able to revive a tardigrade (named SB-1) who was in this state and stored in a lab at -4 °F for 30 years, breaking the 9-year record held at that time. SB-1 fully recovered all natural functionality and was even able to restart reproduction after the ordeal.
Tardigrades, given that they are able to survive extreme conditions, have shown quite the knack for enduring the space environment. The European Space Agency (ESA) performed an experiment in 2007, in which a group of tardigrades were directly exposed to the space environment, achieving a shocking 68% survival rate. A later 2021 experiment headed by the NASA Ames Research Center called Cell Science-04 launched on SpX-22 and bound for the ISS, aimed to learn even more about tardigrades and the genes that contribute to their resilient survival. By studying their RNA over multiple generations, the goal was to analyze which specific genes allow them to mediate environmental stress and exposure. If scientists are able to understand what genetic components are at play, it could lead to therapies applicable to humans, easing our transition to the space environment for deep space travel.
While this may seem like science fiction, as do many grand ideas before they become reality, experiments onboard the ISS have and continue to expand human knowledge - from studies on disease, development of targeted drug therapies, space agriculture, 3D printing of human tissue, and so much more. There’s much we can learn from the smallest of organisms and a microgravity laboratory is the prime location. When cells are put onto slides and observed on Earth, they are under the ever-present force of gravity, squishing the cells flat once removed from the body. In microgravity, cells retain the shape much like they would have inside the human body, allowing scientists to target attack points on cancer cells for new therapies.
Many look at the human presence in space as a luxury; something we don’t need to do, but something we want to do because it’s new and shiny. The truth of the matter is that space travel is a necessity if we want to continue to grow and learn as a species. Common barriers to this may seem obvious: how to get there, how to survive in the space environment, and how to pay for it. The less obvious, but far more dangerous, problem is how do we protect these vital assets once they’re in place? Among the factors risking this future, orbital debris continues to grow at an exponential rate, and if we don’t do something about it (and soon) we’re looking at a massive barrier to furthering human knowledge and expanding our presence in space. Our astronauts, spacecraft, and satellites might not yet have the high survivability of these water bears, but given the time to study in space without a clobbering by errant debris, we might one day be as hardy as SB-1.
Sources
https://earthsky.org/space/water-bears-tardigrades-into-space-iss-experiment/
https://kids.frontiersin.org/articles/10.3389/frym.2021.573691
https://www.nasa.gov/johnson/HWHAP/water-bears-in-space
https://science.nasa.gov/biological-physical/investigations/cell-science-04
https://serc.carleton.edu/microbelife/topics/tardigrade/index.html
https://www.livescience.com/57985-tardigrade-facts.html
https://phys.org/news/2016-01-tardigrade-brought-life-frozen-years.html
Recommended column to read next: Lost in Space-Based Navigation