[ExI] Astronauts Suffer Significant, Permanent Bone Density Loss in Space

[BillK]

<https://www.extremetech.com/extreme/337611-astronauts-suffer-significant-permanent-bone-density-loss-in-space>
By Ryan Whitwam on July 1, 2022

Quotes:
Even after a year back on Earth, bone density does not fully recover.
Essentially, being in space for even a few months causes your bones to
age at an increased rate — as much as 10 years per flight.
Astronauts who were on the International Space Station for longer than
six months recovered less of their bone density after returning. That
suggests that long-term missions, like the ones planned for the
Artemis Program, could have serious impacts on astronaut health down
the road. It also raises more questions about how humans would fare
long-term in an environment where there is less gravity than Earth,
for example on the Moon or Mars.
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Astronauts do exercise while on the ISS, to help prevent muscle wastage.
But 2 hours of exercise per day means that the other 22 hours are the
equivalent of lying in bed. I think long-term missions over six months
duration will have to have a rotating section that provides an earth
gravity environment using centrifugal force.

BillK