Book 8, Question 80
Why Do Astronauts Grow a Little Taller in Space?
Astronauts grow a little taller in space because without gravity pressing down, their spines stretch out.
Astronauts grow a little taller in space because gravity stops squeezing their spines! Without gravity squeezing down, the cushions between the bones of the spine spread out. Astronauts can grow about 3 percent taller.
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Quick answers
How much taller do they get?
NASA has found that astronauts grow about 3% taller in their first 3 to 4 days of weightlessness.
Who grew taller?
NASA astronaut Kate Rubins grew from 171 centimeters on Earth to 174.4 centimeters in space.
Source: NASA
More fun facts
- On Earth, gravity squeezes the body all day long.
- In space there is almost no pull of gravity pressing down, so the body stretches out.
- NASA has found that astronauts grow about 3% taller in their first 3 to 4 days of weightlessness.
- Almost all of that extra height comes from changes in the spine.
- NASA astronaut Kate Rubins grew from 171 centimeters on Earth to 174.4 centimeters in space.
- Their shoulders rise too, so their arms end up farther from the floor than on Earth.
- Back on Earth, astronauts usually return to their normal height in a short time.
Sources: NASA
Questions kids ask
Why does NASA care how tall astronauts get?
Body measurements decide things like seat sizes, hatch openings and spacesuit fit, and whether astronauts can reach buttons and switches.