Biologist Jessica U. Meir has devoted her life to studying animals that thrive in Earth’s most extreme environments, hoping to unlock the secrets of high-flying geese that soar over Mount Everest and emperor penguins that dive thousands of feet under the Antarctic ice. But all the while, the 35-year-old Meir has hoped, too, that she would have a chance to explore the most extreme environment of them all: outer space. Meir is an assistant professor of anesthesia at HMS and Massachusetts General Hospital.