Astronauts aboard the International Space Station are spending their days doing more than maintaining a research laboratory in orbit. They are also becoming living subjects in some of the most unusual medical experiments on Earth or, more accurately, far above it.
As members of Expedition 74 undergo blood pressure measurements, vein scans, eye examinations and cognitive testing, researchers are using the extreme environment of space to study how the human body changes when gravity is no longer pulling it down in the usual way.
