It isn’t just humans onboard the International Space Station (ISS). Among the many creatures that have accompanied astronauts up in the ISS – from quails to Hawaiian bobtail squid – few have been more helpful than the numerous waves of mice that have graced the NASA Rodent Research Facility.
But how do these astronautical rodents cope with the freak conditions of space travel? Well, let’s just say mice in microgravity are quite a sight to behold.
A new study, published in the journal Scientific Reports, has taken the most extensive look at the behavior of mice in space to date. A gang of 20 mice was observed following a four-day journey from Earth to the ISS, during which time their behavior was documented by a number of cameras.
By and large, it seems mice are actually surprisingly good space travelers. Video segments captured by the crew showed the mice engaging in a range of normal happy behavior, such as eating, ambulation, self-grooming, and “amicable social interactions”, which is science-speak for cuddling.
“All 20 mice flown on the first foray of the NASA Rodent Habitat on ISS maintained excellent health during the mission,” the study authors write.
“The mice showed consistent, robust levels of physical activity throughout the mission,” they added. “Post-flight, body weights were comparable to [ground control] mice, and coat condition was excellent indicating that grooming was effective.”
However, after a week of space travel, some of the younger mice did start to exhibit some strange behavior. As the footage shows, many of the mice were observed performing loop-the-loops around the cage like hyperactive daredevils. The behavior would start with just one mouse running in loops around the cage, but would quickly become a coordinated group activity.
The researchers aren’t totally sure what the mice were trying to achieve by doing this, but note the behavior is unique to spaceflight and is most likely performed because of the “rewarding effects of physical exercise”.
These positive results are also good news for humans. Plans for crewed missions to Mars are getting serious, so scientists are desperately attempting to figure out the effects of long-term space travel on the human body. Mice are a pretty good proxy for this, but there have also been extensive human studies on the matter too.
NASA's “twin study” was also published this week. This landmark piece of research involved identifying the changes in biology experienced by Scott Kelly after his year aboard the ISS, comparing him to his identical twin, Mark Kelly, who remained back home on Earth. You can read the findings of this study right here.