Over the past few decades, humanity has begun to explore Mars much more actively. There are now 8 active missions on or near the Red Planet, and by the end of the decade it is planned to send 7 more robotic lander, rover or orbiter. And by 2030, several space agencies are planning to land a crew on the planet's surface.
There are many volunteers who are willing to take a one-way trip to Mars and people who wish to turn the planet into their new home. All of these proposals have focused the attention of scientists on the specific dangers that appear when sending people to Mars. In addition to the dry and cold environment of the planet, lack of air and sandstorms, there is also a high risk of radiation radiation.
The reasons
Mars does not have the protective magnetosphere that Earth has. Scientists speculate that at one time Mars also had convection currents in its core, creating a dynamo effect that set in motion a planetary magnetic field. However, about 4.2 billion years ago, due to the impact of a large object or the rapid cooling of the core, the dynamo effect ceased.
As a result, over the next 500 million years, the atmosphere of Mars slowly disappeared due to the solar wind. Without an atmosphere, the planet is exposed to a higher level of radiation than the Earth. In addition to this, lethal explosions are also observed during strong solar flares.
Research
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NASA's Mars Odyssey spacecraft was shipped in 2001. It was equipped with a special instrument MARIE (Martian Radiation Experiment) designed to measure the radiation environment around Mars. Since the planet has a thin atmosphere, the radiation detected by the apparatus will be approximately the same as on the surface.
During about 18 months of data collection, Mars Oddysey determined that radiation was 2.5 times the level on the International Space Station at 22 millirad per day, which is comparable to 8000 millirad (8 rad) per year. The device also recorded 2 events with solar protons, when the radiation level rose to 2000 millirad per day, and several smaller events, with a level of up to 100 millirad per day.
By comparison, people in developed countries, on average, are exposed to radiation levels of 0.62 rad per year. Studies show that a person can cope with a dose of up to 200 rad without significant damage to health, however, with prolonged exposure to the levels of radiation that were found on Mars, all types of diseases can begin to appear: acute radiation sickness, increased risk of cancer, genetic damage, death.
Given the fact that any level of radiation above the norm has a certain degree of risk, NASA and other agencies have strict ALARA policies when planning their missions. It involves the implementation of safety systems to reduce radiation to a reasonable and achievable level.
Possible solutions
Future explorers of Mars will definitely have to face increased levels of radiation. Moreover, any attempts and plans to colonize the planet will require the adoption of many effective measures to ensure a minimum level of radiation exposure. Several promising solutions (both short-term and long-term) have already been proposed.
For example, NASA currently operates several satellites exploring the Sun, the outer space of our system and observing galactic cosmic rays (GCR). These satellites will enable better understanding of solar radiation. They are also working to find ways to improve the protection of astronauts and electronics.
In 2014, NASA launched the Galactic Cosmic Rays Reduction project. This is an incentive competition that has awarded $ 12,000 for ideas on how to reduce the effects of radiation on astronauts. After the first round in April 2014, another similar round with a $ 30,000 premium was launched in July.
When it comes to long-term stays and colonization, several interesting ideas have been voiced in the past. For example, Robert Zubrin and David Baker, in their Mars Direct mission proposal, described the possibility of building a colony directly in the ground in order to have natural protection from radiation.
Also voiced proposals for the construction of habitats above the surface of the planet, using inflatable modules, clad in ceramics. This would also use Martian soil. A similar idea was proposed by NASA and ESA for the colonization of the moon. According to the idea, special robots with 3D printing function according to the "stove" method should turn sand into molten material using X-rays.
So far, radiation on Mars remains the main problem for future colonizers. For the foreseeable future, colonists are likely to live in the ground or in facilities that provide solid protection from solar and cosmic rays.