What are the pros and cons of being in space for a long time?

Effects of Space
Yuri Romanenko, a Soviet cosmonaut, spent 326 days in the space station Mir. His record time spent in space and the prolonged exposure to weightlessness affect his body.. According to the French magazine L’Express, Romanenko has become one or two inches taller, his muscles have weakened, his bones have become brittle, and his blood volume has decreased by 25 percent. His calf muscles shriveled even though he tried to keep in shape by use of an exercise bicycle and a treadmill. Romanenko jokingly suggested that future cosmonauts have “a bald head to avoid haircuts, big arms—six would be better—and slim legs or just one with grips, to keep steady.”
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