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NAIL: In the video, you mentioned that the focus of ST5's science mission is to study the magnetosphere that shields the Earth from solar storms.

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Can you tell us more about the solar storms and how the magnetosphere protects our planet from them?

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SLAVIN: I'd be glad to. The magnetosphere is really just the high-altitude extension of the Earth's magnetic field.

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Magnetic fields are really interesting and cool, at least if you're a physicist.

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They're very different from other sorts of fields, for example gravity fields or electric fields.

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Those fields, the lines of force that we use to visualize these fields for gravity or electricity, they tend to form straight lines.

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Magnetic fields, however, always close on themselves. It's a law of nature that we really don't understand yet, but it is a fact.

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So these come out of a planet like the Earth -- in our case, they come out of the southern hemisphere --

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and they arc around and form great loops that close in the north.

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Now, these loops go up to an altitude of about 60,000 kilometers. This is about five times the diameter of the Earth

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They're stopped at that altitude because that's where the strength of the

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magnetic field is no longer able to withstand the pressure of all the charged-particle radiation that's coming off of the sun.

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Fortunately, again, as you saw in the piece earlier, the Earth's magnetosphere, namely the Earth's magnetic field,

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is able to shield us from most of the radiation that comes from the sun and even part of the radiation that comes out of the galaxy.

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Our second layer of defense is the Earth's atmosphere itself, but between the two of these, we're usually in pretty good shape.

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