Sending human travelers to Mars will require scientists and engineers to overcome a range of technological barriers, including security. One of these is the serious risk posed by particles emanating from the Sun, distant stars and galaxies.
Answering two key questions would go a long way towards overcoming this hurdle: would particle radiation pose too much of a threat to human life when flying to and from the red planet? And, could timing a flight to Mars help protect astronauts and spacecraft from radiation?
In a new article, published in the peer-reviewed journal Space Weather, an international team of scientists, including researchers from the University of California, Los Angeles, answers these two questions "no" and "yes."
Humans should be able to travel safely to and from Mars, provided the spacecraft is adequately protected and the return trip takes less than four years. The timing of a man's flight to Mars would really make a difference: Scientists have determined that the best time to fly from Earth is when solar activity is at its peak known as solar maximum.
Scientists' calculations show that it would be possible to protect the spacecraft from the energetic particles of the Sun, because during the solar maximum, the most dangerous and energetic particles from distant galaxies are deflected under the influence of increased solar activity.
A journey of this length would be quite possible. The average flight to Mars takes about nine months, so depending on launch times and fuel availability, it is likely that the mission could reach the planet and return to Earth in less than two years, according to Yuri Shprits, a research geophysicist at the University of California, Los -Angeles and co-author of the article.
“This study shows that while cosmic rays impose strict limits on how heavy a spacecraft can be and launch times, and pose technological challenges for human travel to Mars, such a mission is viable,” said Syrz, who is also a department head. space physics and space weather at the Geosciences Research Center GFZ in Potsdam, Germany.
The researchers recommend a mission of no more than four years, because the longer journey would expose astronauts to dangerously high levels 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 hazard to such a flight will be particles from outside our solar system.
Syringe and colleagues at UCLA, MIT, Moscow's Skolkovo Institute of Science and Technology, and GFZ Potsdam have combined geophysical particle emission models for the solar cycle with models of how radiation will affect both human passengers, including its different effects. on various organs of the body, and on the spacecraft. Simulations have shown that a spacecraft shell made of a relatively thick material can help protect astronauts from radiation, but if the shielding is too thick, it can actually increase the amount of secondary radiation they are exposed to.
The two main types of hazardous radiation in space are solar energy particles and galactic cosmic rays; the intensity of each of them depends on solar activity. Galactic cosmic ray activity is lowest in the 6-12 months after solar peak, while solar energy particles are highest during solar maximum, Syringe said.