NASA Sends 20 Laboratory Mice To The ISS

Guess who's taking a trip to outer space? Laboratory mice, 20 of them, as part of an experiment to test zero-gravity effects on the body.

SpaceX's latest cargo mission turned out to be a crowded one. Not only did the journey take the first ever astronaut assistant robot to the International Space Station, but it also shuttled a couple of rodents on board.

The Mice Experiments

The 20 mice are part of a Northwestern University study that aims to help prepare people for the Mars mission by figuring out the effects of zero-gravity on the circadian rhythms, microbiome, and other related physiological systems.

Business Insider reports that the collection of mice consists of 10 identical twins — or decuplets — from two different families, half of which will stay on the ISS for 90 days and the other half for 30 days.

Meanwhile, 20 other mice will stay on Earth as control subjects. These ones will be living in a NASA simulator that has all the same minute-to-minute conditions of the ISS, but with gravity.

"It's important to understand how space travel may impact the circadian system, since it coordinates so many biological processes" Martha Vitaterna, deputy director for Northwestern's Center for Sleep and Circadian Biology, explains. "The exertion of liftoff, absence of gravity, and confined living arrangement all add to the stress of life in space, and the key to adapting may be in the body's ability to maintain harmony across systems."

Getting two strains of mice involved in the project is a deliberate choice to better understand the role of genetic differences when it comes to the body's response to zero gravity. One type is known to be heavy sleepers, while the other sleeps much more lightly.

Studying Twins

It's not the first time that scientists used twins to analyze the effects of space in the body. As part of the Year In Space project, astronaut Scott Kelly spent a record-breaking year in space, while his fellow astronaut and twin brother Mark was Earth-bound.

While the findings of that study was valuable, the astro-mice experiments will have a few advantages over the Kelly twins' observations. Not only are there a lot more of them, but scientists could also more strictly control the conditions of the subjects' lifestyles.

As Business Insider points out, Scott's gut bacteria was found to have changed over his one-year stint in space compared to his Mark's. However, the scientists can't be certain if the shift was due to the space conditions or simply the differences in the brothers' diet.

With mice, the researchers will be able to dictate the exact conditions and hopefully get more definitive answers on space's effects on the human body.