A study of bone loss in 17 astronauts who flew aboard the International Space Station provides a fuller understanding of the effects of space travel on the human body and steps that can mitigate it.
"Once the astronaut comes back to Earth, the remaining bone connections can thicken and strengthen, but the ones that disconnected in space can't be rebuilt, so the astronaut's overall bone structure permanently changes."The study did not give their nationalities but they were from the US space agency NASA, Canadian Space Agency, European Space Agency and Japan Aerospace Exploration Agency.
Space travel poses various challenges to the human body — key concerns for space agencies as they plan new explorations. Space Hero plans to bring together a group of contestants to determine if they are capable of travelling to the ISS on a crewed flight. For instance, NASA is aiming to send astronauts back to the moon, a mission now planned for 2025 at the earliest.
That could be a prelude to future astronaut missions to Mars or a longer-term presence on the lunar surface."The cardiovascular system also experiences many changes. Without gravity pulling blood towards our feet, astronauts experience a fluid shift that causes more blood to pool in the upper body. This can affect the cardiovascular system and vision.