ResearcherHer research focused on understanding the hormonal and behavioral mechanisms underlying the response to stress and coping and applying that knowledge to operational conditions in aviation and space. In parallel, she led the ground research that developed the framework for understanding how spaceflight and Earth's gravity affect the human body.
Joan Vernikos was the first in the U.S. to use both male and female volunteers lying in bed continuously with their head lower than their feet (-6 degrees head down). Conducting these human bed-rest studies was the ideal way to simulate the effects of long-term spaceflight. Russian scientists developed this method after noticing that cosmonauts returning from flight could not sleep properly because they felt they were sliding off the foot of the bed. However, they slept normally and felt level when the foot of the bed was raised 15".