Very, very interesting that you brought this up. In the mid-90s I worked with a NASA HQ employee who worked on a proposal for a manned Mars mission (it was submitted to then-Pres. Clinton, but not approved, obviously).
He told me that the radiation issue was a "show-stopper".
I just did a little digging on my own, and uncovered a very interesting study from around that time (1997), which you can read online at National Academies Press here.
The bottom line: it may not quite be a show-stopper (yet), but it is certainly a Very Big Deal, and quite a bit more research needs to be done before the spacecraft is designed. Interestingly, the study seems to rule out any sort of active shielding (artificial magnetic fields, etc.) in favor of passive shielding. But, how much? And what materials do you use, considering that secondary radiation from particles that are emitted when the shielding is energized is also a risk? To quote the study: "It is not a matter of simply adding more aluminum".
They also raise the issue of monitoring systems that need to be employed in orbit around the sun to signal that solar flares/coronal ejections are imminent, as these are a major source of dangerous radiation.
Very complicated issue...
Slashdot Mirror
Very, very interesting that you brought this up. In the mid-90s I worked with a NASA HQ employee who worked on a proposal for a manned Mars mission (it was submitted to then-Pres. Clinton, but not approved, obviously). He told me that the radiation issue was a "show-stopper". I just did a little digging on my own, and uncovered a very interesting study from around that time (1997), which you can read online at National Academies Press here. The bottom line: it may not quite be a show-stopper (yet), but it is certainly a Very Big Deal, and quite a bit more research needs to be done before the spacecraft is designed. Interestingly, the study seems to rule out any sort of active shielding (artificial magnetic fields, etc.) in favor of passive shielding. But, how much? And what materials do you use, considering that secondary radiation from particles that are emitted when the shielding is energized is also a risk? To quote the study: "It is not a matter of simply adding more aluminum". They also raise the issue of monitoring systems that need to be employed in orbit around the sun to signal that solar flares/coronal ejections are imminent, as these are a major source of dangerous radiation. Very complicated issue...