Science

"Astronauts are exposed to high-energy radiation in space, unlike on Earth, where the atmosphere and planetary magnetic field provide a shield against it...This can lead to DNA damage, increased cancer risk, neurodegenerative effects, cardiovascular issues and immune system dysregulation, experts say."

"The International Space Station (ISS), where astronauts spend much of their time, is somewhat protected from radiation by Earth's magnetosphere, as it's around 250 miles away...But the further you go into space, the more radiation you get exposed to, says Dr Haig Aintablian, director of space medicine at UCLA...'Once you go beyond low Earth orbit, you lose much of the protection of Earth's magnetic field,' he tells Sky News, adding radiation is one of the 'real challenges' deep space poses."

https://news.sky.com/story/what-10-days-of-space-travel-could-mean-for-artemis-astronauts-health-13530012