Manned mission to Mars is viable if it does not exceed four years, concludes international research team

Sending human travelers to Mars would force scientists and engineers to overcome a series of technological and security hurdles. One of them is the serious risk posed by radiation from particles from the sun, distant stars and galaxies.

Answering two key questions would go a long way in overcoming this hurdle: Would particle radiation pose too serious a threat to human life throughout a round trip to the Red Planet? And, could the very moment of a mission to Mars help protect the astronauts and the spacecraft from the radiation?

In a new article published in the peer-reviewed journal Space Weather, an international team of space scientists, including researchers at UCLA, answers these two questions with a “no” and a “yes”.

That is, humans should be able to travel safely to and from Mars, provided the spacecraft is sufficiently armored and the round trip is less than about four years. And the timing of a human mission to Mars would indeed make a difference: Scientists have determined that the best time for a flight to leave Earth would be when solar activity is at its peak, known as the solar maximum.

Scientists’ calculations show that it would be possible to protect a spacecraft bound to Mars from energetic particles of the sun because, during the solar maximum, the most dangerous and energetic particles in distant galaxies are deflected by increased solar activity. .

A trip of this length would be possible. The average flight to Mars takes around nine months, so depending on when it is launched and the fuel available, it’s plausible that a human mission could reach the planet and return to Earth in less than two years, according to Yuri Shprits, a researcher at UCLA. geophysicist and co-author of the article.

“This study shows that although space radiation imposes strict limits on the weight of the spacecraft and the time of its launch, and that it presents technological difficulties for human missions to Mars, such a mission is viable,” said said Shprits, who is also the head of space physics and space weather at the GFZ Research Center for the Geosciences in Potsdam, Germany.

The researchers recommend a mission no longer than four years, as a longer trip would expose the astronauts to a dangerously high amount of radiation during the round trip, even assuming they went there when it was relatively safer than. ‘at other times. They also report that the main danger of such theft would be particles coming from outside our solar system.

Shprits and colleagues at UCLA, MIT, the Moscow Skolkovo Institute of Science and Technology, and GFZ Potsdam combined geophysical models of particle radiation for a solar cycle with models of how radiation would affect to both human passengers, including its varying effects on different bodily organs, and a spacecraft. Modeling determined that having a spacecraft hull constructed from a relatively thick material could help shield astronauts from radiation, but that if the shielding is too thick it could actually increase the amount of secondary radiation to which they are exposed.

The two main types of dangerous radiation in space are solar energetic particles and galactic cosmic rays; the intensity of each depends on solar activity. Galactic cosmic ray activity is lowest within six to 12 months of peak solar activity, while solar energy particle intensity is highest during solar maximum, Shprits said.