With the current technical capacity of Earthlings, a return flight from Earth to Mars should take about 500 days, that is, a year and four and a half months.
The greatest obstacle to human flight to the red planet is cosmic radiation. It consists of two main components: galactic cosmic rays (GCR) and solar cosmic rays (SCR).
Galactic cosmic rays enter the interplanetary space of the solar system from the outside. These rays produce supernova explosions. Such explosions of stars occur at a frequency of about once every 30-50 years.
There are many stars in the universe, so the flow of galactic cosmic rays is constant – particles are ejected by explosions of stars into the universe and set off on a continuous path through it. In this case, explosions give very high energy to GCR particles.
Galactic cosmic rays consist of both light ions (protons) and heavier ions, which are “stripped” nuclei of other chemical elements. Remember that protons are hydrogen nuclei (oneHRS).
The sun’s cosmic rays are particles that are ejected into the interplanetary space of the solar system after solar eruptions. They, like galactic rays, also consist of light and heavy ions. Only the energies of the particles of the cosmic rays of the sun’s rays are lower than those of galactic.
There are also extragalactic cosmic rays entering the Milky Way from other galaxies.
Prior to galactic radiation, a person is absolutely defenseless, as the energies of his particles are extremely high from 106 electron volts (1 MeV) up to 1021 electron volt (1 ZeV).
Heavy ions of cosmic radiation have such a high energy that they “flash” the skin of a spacecraft in outer space, like cannonballs in thin silk.
Radiobiologists at the Joint Institute for Nuclear Research in accelerator experiments with animal cells compared ten years ago the effect of irradiating a living cell with heavy ion beams, neutron beams and photon beams (gamma radiation). It turned out that with the same radiation dose (the same amount of radiation received) it is heavy ions that have the worst effect on a living cell.
Researchers then found out that the cause of such a destructive effect lies in the breaks in both strands of the cell’s DNA. If the body can restore a broken DNA strand, then two strands can not.
If heavy ions, which rush through outer space at enormous speeds and penetrate everything in their path, pass through the astronauts’ brains, they will kill neurons and all other cells. According to NASA experts, from 2 to 13% of expedition participants’ nerve cells will be crossed by at least one iron ion during the March expedition.
Through the nucleus of every cell in the body, a proton will fly once every three days. All this can lead to serious and irreversible violations in the behavior of the crew members, which jeopardizes the mission as a whole.
So far, there have been two ways out of this situation.
First: to provide modern spacecraft with powerful radiation protection. But it will greatly increase the weight of the ship and consequently the fuel consumption.
The second resort: to create a spacecraft that can fly many times faster than modern ones.
An international team of scientists has proposed a third resort: to fly on a modern ship, but to plan its flight time so that it takes into account the peak of the sun’s activity – solar maximum.
In fact, below the solar maximum, the most dangerous particles are pushed out of the solar system by currents of cosmic sunbeams. It is known that the activity of galactic cosmic rays is lower for 6–12 months after the peak of solar activity, while the number of high-energy solar particles is greatest just below the solar maximum.
The researchers substantiated their idea of a third outcome in an article published by the scientific journal Space Weather.
Researchers from the University of California at Los Angeles, the Massachusetts Institute of Technology, the Skolkovo Institute of Science and Technology and the Potsdam Center for Geosciences combined geophysical models for the distribution of cosmic particles in interplanetary space (with respect to solar cycles) with models of the effect of this radiation on astronauts and spacecraft.
Simulations have shown that a spaceship shell built of relatively thick material can help protect interplanetary travelers from radiation. However, if the shield turns out to be too thick, it could become a source of secondary radiation that astronauts will be exposed to inside the ship. The protection will accumulate radiation from the particles it captures.
“This study shows that although cosmic radiation sets strict limits on the weight and launch time of spacecraft, and presents technical challenges for human missions to Mars, such a mission is feasible,” said Yuri Shprits of the Potsdam Center for Space Science. Earth.
The researchers note that Earthlings can fly to Mars and return in less than two years. They also recommend that the mission to Mars should not be longer than four years. Otherwise, the danger to the health of astronauts, even under conditions of estimated solar activity, will be too great (not to mention the fact that the activity of our star sometimes also surprises astronomers).
Earlier we wrote that they in the Russian Federation developed a project for an interplanetary ship.
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