Manned missions to Mars are on the drawing table, but Monday's publication of a research study out of UC Irvine warns that any extended space travel better take into account the long-lasting effects of cosmic radiation on astronauts.
New research posits that exposure to cosmic radiation during space travel may impair brain function and memory, and the effects could last a year or more after space travel ends, said Charles Limoli, lead author of the research paper, which was published today in Scientific Reports and put out by the British science journal Nature.
This study follows a similar one done about a year ago that examined the short-term effects of cosmic rays, according to UC Irvine. Limoli says the findings published Monday signal long-term danger for anyone thinking about heading to Mars, a mission that could take two to three years.
“The problem is, when these high-energy particles traverse a spacecraft and traverse your brain,” Limoli said, “they leave a wake of damage.”
For astronauts, that damage could impair decision-making, mood and memory, he said, adding that “mission-critical performance detriments are a concern."
Cosmic rays are different than gamma or X-rays, Limoli said. Cosmic rays are high-energy protons that are much faster, traveling at near light speed.
The study's conclusion lies in stark contrast to the comments of entrepreneur Elon Musk. Just two weeks ago, Musk spoke at the International Astronautical Congress annual meeting in Guadalajara, Mexico, to outline his plans for a manned mission to Mars.
In the question-and-answer session following his presentation, Musk dismissed the danger of cosmic radiation:
“I actually think the radiation thing, it’s often brought up but I think it’s not too big of a deal,” he said.
Earth’s magnetic field deflects cosmic rays, and the space station orbiting our planet is safe within that magnetosphere. But exposing astronauts to it, especially over the two to three years a Mars mission would take, may be extremely dangerous. And, Limoli said, current shielding technology doesn’t offer much protection.
“They’re just basically so energetic,” he said of cosmic rays, “that we can’t stop them.”
NASA funded the research and hopes to address the concerns in time for a manned mission to Mars in the 2030s. The first big step in that process could come as early as September 2018, with the launch of the Orion manned mission to the moon.
Musk wants to launch his Mars mission sometime in the next decade.