Millisieverts (mSv) are units of measurement for how much radiation has been absorbed by the body. Although the type of radiation is different, 1 mSv of space radiation is roughly the same as ...

(The average person is exposed to about 3 mSv of whole-body background radiation per year from natural sources. A chest X-ray shot typically delivers roughly 0.1 mSv. A CT scan is about 7 mSv.