Physics World
Radiation dose in space
Without the atmosphere and outside most of the magnetic field, the sky is an X-ray source.
A station crew member absorbs roughly the dose of several chest X-rays a day, mostly from galactic cosmic rays and trapped particles. Low orbit is still partly shielded by the magnetosphere; beyond it, on the way to the Moon or Mars, the dose rises several-fold and a large solar particle event could be acutely dangerous within hours. Shielding is heavy and hydrogen-rich materials work best, which is why water and polyethylene get stacked around sleeping quarters rather than lead.
Where it has come up lately
Related terms
EVA (spacewalk)
Working outside the spacecraft, in a suit that is itself a spacecraft.
Life support (ECLSS)
The machinery that keeps the air breathable and the water drinkable, indefinitely.
What weightlessness does to people
Bone loss, fluid shift, weakened hearts and eyesight that does not always come back.
Docking and berthing
Two ways to attach a spacecraft to a station: it flies in, or it is caught and bolted on.
Questions
What is Radiation dose in space?
Without the atmosphere and outside most of the magnetic field, the sky is an X-ray source.
Why does it matter?
Low orbit is still partly shielded by the magnetosphere; beyond it, on the way to the Moon or Mars, the dose rises several-fold and a large solar particle event could be acutely dangerous within hours. Shielding is heavy and hydrogen-rich materials work best, which is why water and polyethylene get stacked around sleeping quarters rather than lead.