Mice living on the International Space Station (ISS) not only adapt to a weightless environment, but one group of adorable rodents have even invented a new game to play while orbiting around the Earth. Now, NASA has released the first detailed study of how mice react to living in space, and the results are adorable.
The NASA Rodent Hardware System aboard the International Space Station has been utilized to carry out nearly a dozen experiments on small mammals since 2014. Contained with in it is the Rodent Habitat module, where mice spend their days during their journey around the Earth. Along with the habitat, the system also contains a transporter, in which mice make their journey from Earth to the ISS, and the Animal Access Unit, which houses the animals as they move between the transporter and habitat.
“Our behavioral study shows that the NASA Rodent Hardware System provides the capability to conduct meaningful long-duration biological research studies on the International Space Station. Experiments conducted in the habitat can focus on how mouse physiology responds to the spaceflight environment during extended missions and on similarities in response to astronaut crew,” said April Ronca, a researcher at NASA’s Ames Research Center.
When the Cat’s Away…
For 37 days, NASA engineers studied the behavior of mice aboard the ISS, comparing their behavior to that of mice who stayed on Earth. After a brief period of confusion, the mice soon learned to anchor themselves to the walls of the habitat, and stretch out their bodies, mimicking the way rodents might stand on their hind legs while exploring their environment on Earth.
The rodent astronauts also invented a new game, not possible on the Earth — running in circles around the walls and ceiling of their habitat. Researchers dubbed this behavior “race-tracking.” The first participants were young females, roughly 16 weeks of age, but the game quickly caught on with the other members of the group twice their age. Why the mice began race-tracking, however, remains a mystery. This game would have provided stimulation to the balance system of the mice, or it may have been a reaction to stress. Another possibility is that the rodents were just having fun.
“Circling emerged spontaneously, following an organized progression beginning with back-and-forth running by mice along habitat surfaces, and propelling themselves by pushing off of walls with hindlimbs,” Ronca and her team explained in a journal article, published in Scientific Reports.
Of Mice and Astronauts
The biology of mice is similar, in many ways, to that of humans, promoting scientists to use the animals in scientific experiments. Microgravity environments like those experienced by occupants of the ISS can weaken bones, as well as play havoc with other bodily systems.
“Rodent spaceflight experiments have contributed significantly to our understanding of the effects of microgravity on biological processes that are directly relevant to humans in space. Rodent studies provide information of the whole biological system, including the effects of microgravity on the structure and function of the sensori-motor, musculoskeletal, nervous, cardiovascular, reproductive and immune systems,” NASA reports.
Mice in space were more active than the control group which stayed on the ground, researchers deduced. At the end of the study, the mice had not lost, nor gained, weight, and their coats were in perfect condition, both signs of healthy animals.
Mice in Space? It’s Just the Beginning
As humans begin to populate the solar system, there is another, more human, reason to learn how animals fare in space — future space travelers will want to bring pets with them as they journey to lives on the Moon, Mars, and beyond.
“These creatures you call mice, you see, they are not quite as they appear. They are merely the protrusion into our dimension of vast hyperintelligent pandimensional beings. The whole business with the cheese and the squeaking is just a front.”
The old man paused, and with a sympathetic frown continued.
“They’ve been experimenting on you, I’m afraid.”
― Douglas Adams, The Hitchhiker’s Guide to the Galaxy
Each habitat is able to house 10 mice or six rats, providing them with a comfortable environment, complete with water, food, fresh air, and lighting.
In the future, NASA plans to conduct rodent studies lasting up to six months, equivalent to a human being spending 20 to 25 years in space.
Fortunately for the mice, there has only been one cat in space so far. But, that is sure to change, so dance away, mice!