The crew of Expedition 1 aboard the International Space Station depends upon life support systems to provide oxygen, absorb carbon dioxide, and manage vaporous emissions from machinery and … themselves. Living on the ISS means more than floating above the Earth–it also means hard work and sharing cramped quarters. Clean air is key to a healthy work and living environment. Life support systems on the ISS must not only supply oxygen and remove carbon dioxide from the cabin’s atmosphere, but also prevent gases like ammonia and acetone, which people emit in small quantities, from accumulating. Vaporous chemicals from science experiments are a potential hazard, too, if they combine in unforeseen ways with other elements in the air supply.