What Happens to the Human Body in Space?

In space, astronauts float because there is no gravity. Without gravity, their bones get weaker and muscles shrink, just like when you don’t use your legs much during a long vacation. Their blood also moves differently, it piles up in the head, making them look swollen. But once they come back to Earth, everything gets used again, and the body starts working hard to fix itself.

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  1. Floating in space feels like being inside a giant zero-gravity pool.
  2. Astronauts sometimes look like they have a bloated face after spending time in space.
  3. When astronauts come back to Earth, they may feel weak and tired for a while.

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