No bathrooms, no showers, no getting up for a quick stretch. The paid volunteers were subjected to a strict high-protein, high-salt diet and an exercise routine "that involves pushing the volunteers down onto vibrating plates while doing upside-down squats," according to ESA. Researchers from the University of Bonne hypothesized that this diet and exercise routine might lessen the bone and muscle loss associated with long-term missions in microgravity. The crazy sci-fi headgear they're wearing is designed to measure how much oxygen each person breathes in and how much carbon dioxide comes out, as a way to study the links between diet, breathing and energy consumption.