Space Daily 10/16/2017
While it's true that space radiation is one of the biggest challenges for a human journey to Mars, it's also true that NASA is developing technologies and countermeasures to ensure a safe and successful journey to the red planet.
"Some people think that radiation will keep NASA from sending people to Mars, but that's not the current situation," said, Pat Troutman, NASA Human Exploration Strategic Analysis Lead. "When we add the various mitigation techniques up, we are optimistic it will lead to a successful Mars mission with a healthy crew that will live a very long and productive life after they return to Earth."
Space radiation is quite different and more dangerous than radiation on Earth. Even though the International Space Station sits just within Earth's protective magnetic field, astronauts receive over ten times the radiation than what's naturally occurring on Earth. Outside the magnetic field there are galactic cosmic rays (GCRs), solar particle events (SPEs) and the Van Allen Belts, which contain trapped space radiation.
NASA is able to protect the crew from SPEs by advising them to shelter in an area with additional shielding materials. However, GCRs are much more challenging to protect against. These highly energetic particles come from all over the galaxy.
More:
http://www.spacedaily.com/reports/Space_radiation_wont_stop_NASAs_human_exploration_999.html
