Crew members on the International Space Station completed more human research investigations in advance of their return home at the end of the month, working to improve the health of future space travelers and residents on Earth. Two crew members spent time tracking how fluids move around the human body in microgravity. NASA astronaut Kate Rubins assisted JAXA (Japan Aerospace Exploration Agency) astronaut Takuya Onishi with ultrasounds and measurements for the study Fluid Shifts Before, During, and After Prolonged Space Flight and Their Association with Intracranial Pressure and Visual Impairment (Fluid Shifts).
One of the main risks for humans during long-duration space missions is change in vision. More than half of American astronauts experience vision changes and other physical alterations to parts of their eyes during and after long-duration spaceflight. It is hypothesized that the fluid shift toward the head that occurs during spaceflight leads to increased pressure in the brain, which may push on the back of the eye, causing it to change shape. Fluid Shifts measures how much fluid shifts from the lower body to the upper body, in or out of cells and blood vessels, and determines the impact these shifts have on fluid pressure in the head, changes in vision and eye structures.