When the space shuttle Discovery lifted off last month, it was carrying a human guinea pig with the crew!
Astronaut Koichi Wakata is the first Japanese Astronaut to have a long stay in the International Space Station. His visit will last three months long.
Since there are no washing machines aboard the space station, Wakata had to take enough clothes to last for his entire stay – which means a whole lot of underwear and socks!
Wakata will report on the state of his underwear, wire himself with sensors, and perform tests like arm wrestling to help scientists back on Earth understand the effects of living in space.