Long Space Travel Might Be Deadly for Astronauts, Study Says

A NASA study has revealed that prolonged exposure to zero gravity can affect how blood flows in astronauts’ bodies. When astronauts complained about visual impairment after a few months on board the International Space Station (ISS), NASA decided to investigate. NASA looked at how zero gravity affected the circulation of upper body fluids by examining 11 healthy astronauts, aged around 46 years old, who have stayed on board the ISS for an average of 6 months. Using ultrasound scanning, researchers monitored the astronauts’ left jugular vein, the blood vessel responsible for transporting blood from the head to the heart. Tests were done before the astronauts’ flight, 50 and 150 days since departure, and 40 days after returning to Earth. Signs of stagnant or reversed blood flow were found in 7 out of the 11 astronauts. Test results also revealed that astronauts’ bodies had difficulty draining fluids normally without the pull of gravity. This could lead to blood clots, which block blood vessels or even lead to death. Michael Stenger, Cardiovascular and Vision Laboratory manager at NASA’s Johnson Space Center, was surprised by the findings and the fact that the astronauts did not show any symptoms of blood clotting. Some experts think that the findings could have serious implications on astronauts’ health and on the success of future space missions. Despite that, the researchers are positive that their study could lead to new developments and treatments to help astronauts in space. One such development is a lower-body vacuum suit currently being tested by NASA. The suit will help distribute blood from the head into the lower body, mirroring gravity’s effect.