NASA’s Expedition 73: Astronauts Study Brain, Balance, and Immunity on ISS

Astronauts aboard the International Space Station are conducting key health experiments as part of Expedition 73, focusing on how the brain and immune system adapt to microgravity. Crew members exercise to counter muscle and bone loss, complete cognitive tests, and practice emergency medical drills. Using virtual-reality equipment, they study balance in weightlessness, while blood and saliva samples help researchers assess immunity changes. NASA says these findings are vital for protecting astronauts on future Moon and Mars missions and may also advance medical knowledge on Earth.