Humans Can Travel to Mars if Mission Is Less Than Four Years

When it comes to sending people to Mars, one of the biggest barriers is the potential effects of the Martian environment on human health. There’s still a lot we don’t know about how living on Mars would affect the health of astronauts, with issues from the potentially toxic dust there to the deadly radiation which bombards the planet.

Now there’s some good news for would-be explorers: A team of researchers from the University of California, Los Angeles have been investigating one part of this puzzle — the amount of radiation that Martian visitors could be exposed to — and they’ve found that the radiation levels shouldn’t be unsafe as long as the mission lasts less than four years.

We’re lucky here on Earth to have a magnetosphere that protects us from radiation, but if you travel outside of the envelope of our planet, as visitors to Mars would have to, then they’ll be exposed to radiation. And we’re still very much in the early stages of understanding what the effects of this could be.

The sticky issue is that there are actually two different types of radiation to content with: Energetic particles from the sun and galactic cosmic rays. Somewhat counterintuitively, the authors say it would actually be best to send a mission to Mars during a solar maximum, when the sun is at its most active. That’s because the sun’s activity can deflect some of the more harmful particles coming from outside the solar system.

We do have shielding technology to protect both spaceships and astronauts from radiation, so the researchers modeled how much radiation astronauts would be exposed to on a round-trip to Mars using current shielding. They found that relatively thick shielding would help keep astronauts safe as long as the trip didn’t last more than four years in total, but that making the shielding too thick would actually be more dangerous as it would increase their exposure to secondary radiation.

“This study shows that while space radiation imposes strict limitations on how heavy the spacecraft can be and the time of launch, and it presents technological difficulties for human missions to Mars, such a mission is viable,” said Yuri Shprits, a UCLA research geophysicist and co-author of the paper.

The research is published in the journal Space Weather.

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