Problems of Dangerous Potentials Mission to Mars Discovered by Scientists

The dangers of cosmic rays

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Cosmic rays are high-energy atomic and subatomic particles derived from star explosions, black holes, and other power sources in space. Cosmic rays can damage DNA, increase cancer risk, cause vision problems (cataracts), damage to the nervous system, and cause problems of blood circulation, and other health effects on astronauts.

Researchers have learned that astronauts in space receive far greater cosmic ray radiation exposure than we stay on Earth because planetary atmospheres absorb much of the harmful energy.

The planet's magnetic field also refracts and diverts large amounts of space radiation, and helps protect astronauts at the International Space Station, orbiting just 250 miles above Earth.

However, the trip to Mars is potentially large in terms of cosmic ray exposure. In addition, the planet Mars has also lost its magnetic field billions of years ago, which will expose additional radiation to the first explorers of Mars.

Frank Cucinotta, a health scientist and colleague of Eliedonna Cacao at the University of Nevada, Las Vegas, examined this issue by re-examining the results of four previous studies on tumors in mice.

In addition to seeking the immediate effects of cosmic rays on mouse cells, which can affect cells to develop into cancer, researchers also see the possibility of how secondary effects or "non-target effects" play a role.

What they found was the risk of cancer in deep spaces (at least for mice) roughly twice as high as previous estimates.

Why is traveling across far space possibly more dangerous than expected?

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Researchers think that this increased risk of cancer leads to how the damaged DNA then spreads throughout the body.

When a cell is exposed to cosmic rays, it releases a chemical signal to other cells, which may trigger nearby healthy cells to also mutate into cancer.

Previous research models, do not take into account this domino effect. Even more worrisome, the type of radiation responsible for health effects "is only slightly reduced using radiation shields," Cucinotta and Cacao wrote in their study. After all, the manned mission of Mars exploration should not be canceled.

Space agencies and private companies have been actively working to minimize space radiation. For example, a pioneering company from Israel is developing a vest designed to absorb radiation better, and a NASA scientist has recently put forward the idea of installing a satellite that serves as an artificial magnetic shield to divert harmful radiation around Mars.

And, as noted by the researchers in their study, there is a "significant difference" between cancer rates in research models applied to mice and those that are actually seen in humans. "This significant difference could limit the application of predictions described in this research paper," they wrote.

However, the scientists also added that the gap in this knowledge is precisely the main reason why future space explorers and their own space agencies should be careful.

"Researchers ... are needed before long-term space missions beyond the protection of the Earth's magnetic field are done," they said.

^{Astrorad's prototype, as a radiation shield for far-flung travel. Credit image}