When gravity is taken away or reduced during space exploration, the blood tends to collect in the upper body instead, resulting in facial edema and other unwelcome side effects. Upon return to earth, the blood begins to pool in the lower extremities again, resulting in orthostatic hypotension."
When the astronauts come back to Earth, they do not have enough fluids in their systems. It takes their bodies a few days to make more blood and water. The astronauts have to rest so their bodies have time to make new blood and water. If they don't, they can feel very weak.
Answers & Comments
Answer:
When gravity is taken away or reduced during space exploration, the blood tends to collect in the upper body instead, resulting in facial edema and other unwelcome side effects. Upon return to earth, the blood begins to pool in the lower extremities again, resulting in orthostatic hypotension."
Answer:
When the astronauts come back to Earth, they do not have enough fluids in their systems. It takes their bodies a few days to make more blood and water. The astronauts have to rest so their bodies have time to make new blood and water. If they don't, they can feel very weak.