Mars trips may involve less radiation exposure than previously thought:
There's no question that the first human mission to Mars will be extremely dangerous. Some studies have suggested that the radiation levels would exceed the maximum career dose for a given astronaut, greatly increasing the risk of cancer and other illnesses. It might not be quite so bad as it sounds, though. Newly presented ESA ExoMars orbiter data indicates that astronauts would receive "at least" 60 percent of their maximum recommended career radiation exposure on a round trip to Mars that takes six months both ways. That's still several times what ISS crew members receive, but it's relatively gentle compared to what some had feared.
(Score: 2) by Immerman on Thursday September 20 2018, @05:10PM
Hmm, you might be right - except about the safer part. It is after all risk of DEATH either way - only the mechanism is in question.
And unfortunately the spacecraft provide pretty close to no shielding. They have to, if they want to avoid killing the passengers. The problem is that you have two kinds of radiation to deal with - low energy and solar wind stuff that's dangerous as-is, and can only be somewhat shielded against without thick, heavy shielding. And high-energy cosmic rays that are (relatively) harmless as-is, but will turn any sort of heavy shielding into deadly radioactive particle cascades that can only be blocked by *extremely* thick shielding on the order of several pounds per square inch.
If you're talking about a "stationary" space station, especially one built from materials harvested in orbit, then extremely thick shielding is no problem. For a ship that has to accelerate though, flimsy "stop the easy stuff" shielding really is about the best you can do - presumably with some sort of heavily shielded "solar flare shelter" that you try to avoid spending too much time close to under other circumstances, since it's going to be constantly spawning those radioactive particle cascades.