Human stem cells become more active in space — and that's not a good thing

Human stem cells in space undergo accelerated aging, losing regenerative ability and becoming vulnerable to DNA damage due to microgravity and cosmic radiation. AI-assisted research on stem cells sent to the International Space Station revealed heightened activity, reduced rest capacity, and increased "dark genome" activity linked to stress and aging. These findings pose challenges for long-duration space missions. However, cellular damage began reversing upon return to Earth, suggesting potential for rejuvenation techniques beneficial to both astronauts and aging research on Earth.