Microbiologist Monsi Roman joined NASA in 1989 to help design the International Space Station. As the chief microbiologist for life support systems on the ISS, Roman was tasked with building air and water systems to support crews in space. That meant predicting how microbes would behave and preventing them from disrupting missions. And so, on today's show, host Aaron Scott talks to Roman about microbes in space: the risks they pose and where they might take us in the future of space travel. Questions about the science happening around you? Email shortwave@npr.org — we'd love to hear about it!