NASA’s future deep space exploration – including to Mars – is an unprecedented venture in spaceflight, requiring us to tackle challenges we’ve never faced before. For instance, we know the human body changes significantly while in space, and we’ll need to find ways to address those effects. NASA is conducting research to learn more about the long-term impact of extended human spaceflight. One experiment that just launched, Rodent Research-9, is contributing to this goal by sending rodents to the International Space Station, to study how a lack of gravity in space affects blood vessels, eyes and joints.