Astronauts Impacted by Radiation Hazards on Mars Trek: Cancer Risk Increases in Deep Space

Sending astronauts to Mars is harder than you might expect. The space travelers will have to deal with long periods away from Earth and conditions that are harsh to life. Yet perhaps the most pressing threat that the astronauts will face on their long trek to the Red Planet will be the dangerous space radiation..

On Thursday, a detector on NASA's Mars Curiosity rover confirmed previous research findings on the hazards of space radiation. Using its radiation-detecting instrument, called RAD, the rover collected data on its eight-month cruise to the Red Planet in 2011 and 2012. Now, researchers have examined the data and have found that models predict that radiation levels on the way to Mars are several hundred times higher than the dose humans receive on Earth.

"As the nation strives to reach an asteroid and Mars in our lifetimes, we're working to solve every puzzle nature poses to keep astronauts safe so they can explore the unknown and return home," said William Gerstenmmaier, NASA's associate administrator for human exploration and operations, in a news release. "As we built the Orion spacecraft and Space Launch System rocket to carry and shelter us in deep space, we'll continue to make the advances we need in life sciences to reduce risks for our explorers."

In general, there are two forms of radiation that are harmful to astronauts in deep space. One is galactic cosmic rays (GCRs), which are particles caused by supernova explosions and other high-energy events outside the solar system. The other is solar energetic particles (SEPs); these are associated with solar flares and coronal mass ejects from the sun.

This radiation can impact astronauts in a variety of ways. Radiation exposure is measured in units of Sievert (Sv) or milliSievert. Long-term population studies have shown that exposure to radiation can increase lifetime cancer risk. More specifically, exposure to a dose of 1 Sv accumulated over time can up your fatal cancer risk by 5 percent.

"In terms of accumulated dose, it's like getting a whole-body CT scan once every five or six days," said Cary Zeitlin, a principal scientist at the Southwest Research Institute, in a news release. "Understanding the radiation environment inside a spacecraft carrying humans to Mars or other deep space destinations is critical for planning future crewed missions."

Currently, researchers are trying to figure out how to shield spacecraft from this harmful radiation. Without designing ways to safely ferry astronauts across deep space, it will be impossible to send people to Mars in the future

The findings are published in the journal Science.