Young would-be space explorers received some bad news this week. Due to the Sun entering in to a phase of relatively low solar activity, cosmic radiation is projected to increase to such levels that any prolonged manned space expedition would prove harmful and even deadly to the astronauts involved. Specifically, a mission to Mars appears to be out of the question for the foreseeable future.
Previously, the United States, China, Japan, Russia and India made statements indicating that eventually placing astronauts on the Red Planet is a priority for their respective space programs, however, a recent study claims that exposing humans to cosmic radiation for hundreds of days as they make the long trek to Mars would most likely severely damage organs and body parts, which could result in their deaths. The study was published by the journal Space Weather.
Currently, the aluminum shielding used on most spacecraft would be insufficient to provide an adequate buffer between astronauts and any radiation they encounter as they journey beyond Earth's protective magnetic field. Unless a significant breakthrough in spacecraft shielding can be made, it appears manned missions to Mars would simply be too dangerous to undertake.
The reason for the increase in cosmic radiation is due to a decrease in the solar winds projected from our Sun. When the Sun is more active, it's solar winds produce electro-magnetic waves that prevent cosmic rays from entering our solar system at any significant level. Our Sun is entering a relatively dormant phase in its activity, which means cosmic radiation will be permeating our solar system until the Sun becomes more active.
It is currently estimated that a 30-year-old male astronaut would need around 400 days to achieve the maximum radiation exposure level, and a 30-year-old female would be need around 300 days. What's more is that if radiation levels continue to rise in our solar system, the time allowable for humans to remain in space beyond Earth could decrease by as much as 20%.
Given that a trip to Mars would require astronauts to spend approximately one year in space, that would put male and female astronauts at serious risk for health complications and death.