Soon there won’t be any cosmonauts on the ISS, but new residents will soon arrive, and while they might not be as helpful as cosmonauts, they may be cuddlier. Elon Musk calls them “mousetronauts,” and in August they’ll fly to the ISS on a SpaceX Dragon cargo ship to be part of a NASA study on the physiological effects of long-duration weightlessness.
The rodent research focuses on the physiological changes that occur when living for long periods in zero or microgravity. Even though astronauts exercise while on the ISS, they invariably lose muscle, immune system capabilities, and bone density, among other problems. Prolonged stays in microgravity also affect the nervous, endocrine, and reproductive systems, as well as genetic and molecular processes. Researchers believe that studying the mice will help them learn how and why these changes occur.