Although we already have several rovers simultaneously circulating on the surface of Mars, one of the great milestones of space exploration would undoubtedly be to send a manned mission to our neighboring planet. Such a journey requires overcoming a series of technological and safety obstacles, including the serious health risk posed by exposure to radiation from particles from the sun, distant stars, and galaxies.
Now, an article published in the magazine Space Weather offers an optimistic perspective on the matter: future missions to Mars may be safe, provided they do not exceed four years in duration, that the spacecraft has optimal armor and that the flight start coinciding with the solar maximum, which is the point at which solar activity reaches its maximum.
Scientists argue that during this time, the most energetic and dangerous particles that reach our environment from other galaxies are deflected by solar activity, so that it would be easier to protect the spacecraft bound for Mars.
How to avoid dangerous radiation from space
An average flight to Mars takes around nine months so, depending on the timing of the launch and the fuel available, it is plausible that a human mission could reach the planet and return to Earth in less than two years . “This study shows that, although space radiation imposes strict limitations on the weight of the spacecraft and the moment of launch, and presents technological difficulties for human missions, such a trip is feasible,” explained Yuri Shprits, a researcher at the University from California – Los Angeles and co-author of the work.
A trip lasting more than four years would expose astronauts to a dangerously high amount of radiation during the round trip, even assuming the trip took place at the safest solar time. The two main types of dangerous radiation in space are energetic solar particles and galactic cosmic rays ; the intensity of each depends on solar activity. The activity of galactic cosmic rays, which is the most dangerous for astronauts, is lowest within six to twelve months after the peak of solar activity, while the intensity of solar energetic particles is greatest during solar maximum.
To reach their conclusions, the scientists combined geophysical models of particle radiation for a solar cycle with models that predict how radiation would affect both the spacecraft and human passengers , including its effects on different organs of the body. The results indicated that shielding the ship’s deck with relatively thick material could help protect astronauts from radiation. However, if the shielding is too thick, the amount of secondary radiation to which they are exposed could be increased.
Referencia: M.I. Dobynde, Y.Y. Shprits, A.Yu. Drozdov, J. Hoffman, J. Li. Beating 1 Sievert: Optimal Radiation Shielding of Astronauts on a Mission to Mars. Space Weather, 2021; DOI: 10.1029/2021SW002749
Text: University of California – Los Angeles
