Sweat is already a nuisance enough to deal with while jogging on a treadmill at your local gym. Now try sweating while you are 250 miles above Earth, with no gravity to help drain it away. During his Blue Dot mission aboard the International Space Station in 2014, ESA astronaut Alexander Gerst wore specially designed shirts while exercising on the station's bike as part of SpaceTex, an experiment that investigated how clothing manages heat and sweat in microgravity. Gerst's mission lasted 165 days, from May 28 to November 10, rather than a full six months. On Earth, gravity pulls sweat downward, while airflow helps it evaporate. In microgravity, these processes work differently. NASA explains that the lack of natural convection in space affects how heat is transported and how clothing interacts with moisture. Astronauts have also reported sweating more during exercise in space than they do on Earth and have described the sensation of heat surrounding the body.
Why was fabric science more crucial in space than on Earth?
