Scitech | Space odyssey made possible by magnetic shields

Researchers simulate earth’s magnetic field to protect space ships

If you think Montreal winters are bad, try taking a trip to Mars. Scientists say that deadly space weather is the greatest obstacle preventing manned missions into deep space, including excursions to our red neighbour. Now, researchers at the Rutherford Appleton Laboratory in Oxfordshire and the universities of York and Strathclyde have demonstrated how spacecrafts and their inhabitants may be protected from the wrath of cosmic solar rays.

The sun is a constant source of charged particles that hurl through the solar system at high speeds and extreme temperatures. Streaming from the sun as solar wind or plasma, these particles occasionally gather into storms with little warning. Dr. Kieran Gibson, a plasma physicist and member of this breakthrough research team, described the threat these storms present to astronauts.

“If a spacecraft doesn’t have some form of protection, astronauts going on a mission to Mars would be bombarded by particles from the sun and would end up dying of radiation poisoning,” Gibson said.

Such high levels of radiation can be strong enough to shred apart human DNA. Skin would burn and blister, teeth and hair would fall out, and internal organs would eventually shut down completely.

On Earth, the magnetosphere, a giant magnetic bubble that surrounds the planet, protects us from solar plasma by scattering energetic particles away. This natural protection inspired the Rutherford scientists to develop a mini-magnetosphere, a small-scale magnetic field designed to surround spacecrafts and deflect solar wind that mimics Earth’s natural protection.

The researchers used knowledge of controlled fusion – combining two atomic nuclei to release massive amounts of energy – to simulate the high-energy plasma found beyond the armoured defence of the magnetosphere, deep in space. They shot the plasma at a model spacecraft enveloped by a mini-magnetosphere created in-lab, and found that the magnetic shield provided almost complete protection. According to the electronic journal Plasma Physics and Controlled Fusion, these findings “demonstrate the potential viability of being able to create a ‘hole’ in the solar wind plasma in which an inhabited spacecraft could reside in relative safety.”

So far, the only humans to have travelled beyond Earth’s magnetosphere were on the Apollo moon missions. Because it takes only eight days to reach the moon, astronauts were able to plan their trip safely to avoid encountering a solar storm. The 36-million mile journey to Mars, on the other hand, would take about 18 months; hitting a storm would be virtually inevitable.

Scientists have long been thinking of ways to dodge this cosmic radiation. In fact, the idea of creating a magnetosphere arose about 30 years ago, but physicists calculated that it would have to be huge – hundreds of kilometres across – and too energetically costly to be feasible. But now, according to Gibson, researchers have shown this not to be the case.

“We have found that their calculations were wrong,” Gibson said. “We set up a little experiment where we simulated what the sun does, looked at the effect of these particles, and found that the magnetosphere does not have to be that big.”

A field as small as 100 metres across would be enough to offer protection while being sufficiently energy efficient and economical, Gibson said.

While this new technology may represent a giant leap for mankind, it is still in its preliminary stages and is not yet ready for practical application. Gibson explained it may still be a few decades before a trip to Mars is really possible.

“This is the start of the journey, rather than the end, but these are very encouraging preliminary results.”


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