Jan 26, 2022

Teeming Life on the ISS

The International Space Station orbits Earth in the cold, solitary vastness of space. But look closer. There’s a cornucopia of species bringing the interior of the station to life, and with it a plethora of scientific knowledge contributing to humans learning not only how to survive in space, but thrive both on Earth and beyond the edge of our planet.

Animals that fly in the air, animals that swim, squirt and float in water, animals that, creep, crawl, walk and run on land – all are being studied to learn how they react, and adapt to microgravity conditions. Since many share similar cells, tissues and other organic structures to humans, each is studied for what they can reveal to help astronauts withstand the rigors of long-range space travel. Some examples:

The tardigrade, or Water Bear, is well known to possess genes that can withstand extreme hot and cold temperatures, dehydration and radiation. What can we learn from these amazing creatures that might help keep astronauts safer in extreme environments?

Astronauts exercise two hours a day and closely monitor their diet, however the loss of muscle mass that occurs in space is still a serious obstacle that researchers are working to overcome. As such Roundworms were exposed to a microscopic obstacle course to study their unusual muscle strength, while Zebrafish have helped researchers develop countermeasures for muscle weakness. 

Another fish, the Japanese medaka, have helped improve our understanding of the mechanisms behind organ tissue changes.

And of course, one of the most common space travelers, the rodent, was found to be more physically active in space than their Earth-bound counterparts in one experiment. Why? This matters to scientists who are studying the effect of microgravity on bone loss. 

Jennifer Buchli is the deputy chief scientist for the International Space Station Program Research Office at NASA’s Johnson Space Center. She explains how studying multi generational organisms can have a big impacts on our understanding of both animal and plant biology in space. 

“Fruit flies multiply so quickly, we can observe several generations at one time. We can trace the actual development of an organism from conception to birth to adulthood and old age. And the genetic changes from one generation to another are easy to track.”

Regarding plants, Buchli says: “Plants develop differently in microgravity. They don't know which way is down anymore. They no longer have a gravity signal for their root structure. So we examine their RNA to see how it’s giving directions and signals, and how that differs from the way plants behave on Earth.” Many types of plants are grown on the station, from flowering plants to leafy greens to vegetables. What we learn could influence our approach to growing different plant types in the future.

Practical benefits for those on Earth have come from studying all these various forms of life in space. Traditional fertilizer can’t be used on plants in space, as they’re not grown with traditional soil. As a result, NASA scientists, working closely with the private sector, developed a fertilizer that would release its nutrients over a specific amount of time. The process proved to be not only successful in space - it can also be used on Earth in vertical farms and urban plant factories. 

Life in space is not new. The study of numerous species going back several decades have given researchers multiple views of how life can exist and thrive in the harsh environment of space. 

Buchli concludes: “We’ll conduct hundreds of experiments during each six-month expedition. We want to study a broad diversity of organisms that will help us travel beyond low earth orbit, while also giving us insights that may improve life on Earth.”

For more information about the multitude of life on board the Space Station, go to

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