Scientists have found that a crewed mission to Mars can last a maximum of four years. This is due to cosmic radiation.
An international team of scientists has calculated that a flight to Mars with a crew should last no more than four years, since the health of astronauts is threatened by prolonged exposure to cosmic radiation.
Planning a mission to Mars is one of the greatest challenges facing humanity. Every aspect of such a multi-year adventure must be carefully considered, as the mission has no room for error.
In addition to aspects such as engine type, crew size, diet, and a thousand other things, the constant radiation hazard must also be considered when planning. Once outside the protective shell of the Earth's atmosphere and its magnetic field, astronauts will be at the mercy of the sun's cosmic rays, so the question arises how to minimize this threat.
Time and shielding materials are the keys to protecting astronauts flying to the Red Planet, according to a recent study by scientists from the University of California, Los Angeles, MIT, and the Skolkovo Institute of Science and Technology.
An important point is that cosmic radiation is not constant. The Sun has an 11-year cycle, during which the activity of the star changes.
However, this is not the only problem. There are two sources of cosmic rays. One of them is the Sun, which emits solar energy particles (SEP). They are generally lighter and less energetic than Galactic Cosmic Rays (GCR), which are generated by supernovae, black holes, quasars and similar high-energy phenomena.
GCR beams are often composed of very heavy particles that travel at speeds and energies hardly achievable in the most powerful particle accelerators on Earth, and can cause significant damage to living tissue over time.
The good news is that the Sun can act as a temporary shield from the GCR. When our luminary is most active, solar winds become very strong and can reflect the GCR, which means that astronauts will be mostly exposed to less energetic SEPs.
According to the study's calculations, since GCR activity is at its lowest for 6-12 months after maximum solar activity, a two-year flight to Mars would be most practical. However, a mission spanning over four years will expose the crew to dangerous levels of radiation.
There are many different ways to protect an astronaut, including heavy metal plates, water tanks, or low density polymer plates. However, the problem is that heavy shielding materials increase the weight of the spacecraft by amounts that are unacceptable for a mission.
“This study shows that while cosmic radiation imposes severe restrictions on how heavy a spacecraft can be and at launch times, and presents technological challenges for human flights to Mars, such a mission is viable,” says Yuri Shprits, a researcher. geophysicist at the University of California, Los Angeles.