Orbiting animals

What 6 animals on the ISS teach us about life in space

Originally Published: 

Even as people are pondering long-term human settlements on other worlds, there’s a lot we don’t know about how life away from Earth affects living things.

Bettmann/Bettmann/Getty Images

To help make our next steps off the planet smoother, NASA and other space agencies have long used animals to test the effects of space.

That may conjure images of lost space dogs, but modern regulations make experiments on animals in space these days more humane and more scientifically sound.


Here are 6 animals that have gone to the ISS in the name of science.

1. Spiders

The history of spiders in space goes back to 1973, when a Skylab experiment proposed by high schooler Judith Miles proved that they can spin webs without gravity.

A similar experiment in 2011 showed that orb spiders on the International Space Stationcan use light to orient themselves in the absence of gravity.

2. Zebrafish

Barcroft Media/Barcroft Media/Getty Images

The transparent skin of the zebrafish makes them interesting to scientists who want to study the inner workings of living animals.

South China Morning Post/South China Morning Post/Getty Images

Zebrafish have been studied on the ISS to better understand the process of muscle atrophy in space, a medical condition that makes it more difficult for astronauts to readjust to life on solid ground.

3. Pavement ants

ViewStock/View Stock/Getty Images

NASA is drawn to ants not for their physiology, but for their ability to cooperate when searching for food.

Scientists studied ants aboard the ISS to find out how the lack of gravity affected their searches. This can lead to new search algorithms for robots.

4. Mice

Viktor Maksimov / 500px/500px/Getty Images

Mice have long been popular scientific test subjects thanks to their biological similarities to humans. Even in space, they can’t escape the attention of scientists.

Astronauts study mice in space to see how a lack of gravity affects mouse behavior and health. In both cases, mice seem to be remarkably adaptable.

One fun quirk of space mice: They developed a routine of running laps around their cages in groups, and scientists aren’t quite sure why.

5. Tardigrades


Tardigrades (more adorably known as water bears) are some of the most resilient animals known to science. That makes them ideal for experiments in the harsh environment of space.


NASA’s next planned tardigrade experiment will investigate their famed adaptability to help develop better ways for humans to combat the stresses of life in space.

SeaTops/imageBROKER/Getty Images

The tiny bobtail squid have a symbiotic relationship with a type of bioluminescent bacteria, which makes them useful subjects to study beneficial animal-microbe relationships.

SeaTops/imageBROKER/Getty Images

NASA is using them to study how gravity affects the animal-microbe relationship, which could lead to better human health in space and on Earth.


Read more stories on space here.

Thanks for reading,
head home for more!