For humans on Mars, the best radiation shield can be a deceptively rustic mixture

For humans on Mars, the best radiation shield can be a deceptively rustic mixture

The planet Mars call us. At least that is the impression you get when you review all planned and proposed assignments red planet in the coming decade. With so many space organizations currently sending missions there to characterize its environment, atmosphere, and geological history, it seems likely that crew missions are just around the corner.

In fact, both NASA and China have made it clear that they intend to send assignments to March in the early 2030s which will culminate in the creation of habitats on the surface.

What is new – To ensure the health and safety of astronauts, both during transit and on the surface of Mars, scientists are investigating several ways to protect radiation. In a recent studya team from Blue Marble Space Institute of Science studied how different materials can be used to create radiation-protecting structures.

This included materials obtained from the soil and those that can be harvested directly from the Martian environment. This is in line with In-Situ Resource Usage process, where local resources are used to meet the needs of the astronaut crews and the mission.

The research was led by Dionysios Gakis, a visiting researcher at the institute and a physics graduate from the University of Patras, Greece. He was joined by Dimitra Atri, a senior research researcher at the institute, a physics professor at the Center for Space Science at New York University Abu Dhabi and Gaki’s academic advisor. The newspaper describing their findings (“Model the effectiveness of radiation-protecting materials for astronaut protection on Mars “) is being considered for publication of the journal Acta Astronautica.

The haze above Mars is the planet’s atmosphere, as seen by the NASA spacecraft Viking 1. It is too thin to protect humans from space radiation.NASA

Why it matters – The radiant environment on Mars is significantly more dangerous than Earth’s due to its thin atmosphere and the lack of a planetary magnetic field. On earth, people in developed countries are exposed to the average 0.62 row (6.2 mSv) per year, while the surface of Mars receives about 24.45 rads (244.5 mSv) per year – and even more when solar events (aka. solar eruptions) occur. As Atri told me The universe today via e-mail, this radiation comes in several forms:

“Galactic cosmic rays consist of charged particles that are one billion (or more) times more energetic than visible light. They can penetrate through shielding and cause irreparable damage to the human body. In addition, solar storms can sometimes accelerate charged particles to very high energies (Solar Energetic Particles). “, which can cause comparable damage. The amount of radiation coming from cosmic radiation is very predictable while solar storms are very difficult to predict.”

The Earth’s magnetosphere, depicted in blue, helps block cosmic radiation from affecting humans on Earth.NASA

How they did it – For their study, Gakis and Atri investigated the properties of various shielding materials that could be transported to Mars or harvested on site. These consisted of materials common in the aerospace industry – such as aluminum, polyethylene, cyclohexane, polymethyl methacrylate, Mylar and Kevlar – and water, hydrocarbon liquid fiber and regolith from Mars. As Gakis explained, they judged each of these materials using GEANT4 numerical model – a software suite that simulates the passage of particles through matter using statistics Monte Carlo methods.

“We built a computational model of Mars and measured the cosmic energy deposition inside a hypothetical human phantom, which represents an astronaut,” he said.

“A shield of material was set to absorb some of the radiation before it reached the astronaut. The most effective materials, in terms of radiation protection, were those that let the least energy into the astronaut’s body.”

Their results showed that hydrogen-rich materials (ie water ice) have a predictable response to galactic cosmic rays and are therefore the best defense against cosmic radiation. They further found that regolith has an intermediate response and can therefore be used for additional shielding – especially in combination with aluminum. In Gakis:

“For example, although aluminum has not been shown to be as effective as other materials, it may still be helpful in reducing radiation doses, and we advocate combining it with other materials. The Mars regolith has similar behavior and the benefit of being a material. in place, which does not require us to carry it from the earth. “

The crab nebula is a remnant of a supernova that is six light-years wide. Galactic cosmic rays flowing into our solar system can come from clusters such as Nebulosan.NASA / ESA / Arizona State University

What’s next – NASA and other space organizations are evaluating several designs, materials and technologies that will enable the creation of habitats on the moon, Mars and beyond. In particular, NASA and the Chinese National Space Agency are planning crew missions to Mars in the coming decade, which will be launched every 26 months (beginning in 2033) and culminate in the creation of surface habitats.

According to Gakis and Atri’s analysis, these habitats are likely to consist of an internal structure designed using lightweight materials that are transported at low cost from the earth.

In the case of aluminum and carbon fiber, they could be produced on site using aluminum extracted from rocks from March and coal harvested from its atmosphere. These can then be protected with the help of locally harvested water ice and regolith, which robots will 3-D-print to create a protective superstructure. Such habitats will enable long-term missions far beyond the Earth and can even be a springboard to permanent human settlements in space.

“Radiation is one of the many issues that humanity must address in order to successfully bring about man. [exploration of] the red planet, ”Gakis concluded.

“We believe our research is another step in understanding the devastating effects of cosmic rays on the Martian environment and planning effective mitigation strategies for future crew missions to Mars.”

This article was originally published on The universe today past Matt Williams. Read original article here.

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