Astronauts on a future mission to Mars could survive radiation levels on the Red Planet's surface, according to a NASA expert.
At a recent press briefing, the scientist in charge of monitoring radiation data collected by the Curiosity Mars rover said energy levels on the planet's surface fluctuate with time of day and the season but are roughly equivalent to what astronauts experience now in the International Space Station.
"Absolutely, astronauts can live in this environment," said Don Hassler, of Boulder, Colo.'s, Southwest Research Institute. Hassler is the principal investigator for Curiosity's Radiation Assessment Detector, or RAD.
"It’s never really been a question of if we can go to Mars, it’s a matter of when we go, how do we best protect our astronauts," Hassler said.
On Earth, life is shielded from powerful radiation emitted by the sun and other cosmic sources by a thick atmosphere and a magnetic field. Mars however lacks those qualities, and visiting astronauts would be exposed to far higher levels of radiation.
Hassler said that even though the RAD has yet to experience a solar flare or storm — an event that would greatly increase radiation levels — it should be possible to manage the overall dosage of radiation that astronauts will sustain during a two-year mission to Mars.
Astronauts are given a "career limit" of radiation exposure they can endure while in space. That limit determines how long they can be exposed to solar and cosmic rays before they risk serious health consequences such as increased risk of cancer, sterility, and gene mutation. Due to the extremely long time-frame involved in a Mars mission, astronauts will meet or exceed that career limit unless they are properly protected.
Solar storms are of particular concern. Exposure to radiation during such an event while walking on Mars' surface, or while walking in space, would probably cause immediate illness.
"That could have an acute effect which could cause vomiting in their space suit and jeopardize the mission," Hassler said. "But on a normal day when an astronaut is on a space walk in deep space, it's really just a question of numbers. They’re accumulating a radiation dose and at some point they’re going to hit their career limit."