For chemical specialist George Aldrich, his keen sense of scent doesn’t just make him an expert—it acts as NASA’s first line of olfactory defense. As the organization’s self-described “Nasalnaut,” whose nose is government-certified three times a year, Aldrich conducts toxicity tests on all objects before they’re sent into space. In his forty-odd years working at the agency’s White Sands Test Facility’s Molecular Desorption and Analysis Laboratory, in New Mexico, he has completed more than 800 “smell missions” to detect potentially noxious and unpleasant smells that might harm or distract astronauts from completing their missions—or, more importantly, tamper with the delicately balanced internal climate of a space shuttle’s confined quarters. After all, you can’t just crack a window when you’re hurtling through outer space.