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The HERTS electric sail, or E-Sail,

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could send spacecraft to the edge

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of the solar system, known as the

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Heliopause, approximately 100

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astronomical units from Earth, in

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less than 10 years. Much faster than

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any current propulsion system.

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For example, it took the Voyager

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spacecraft 35 years to reach

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the edge of the solar system.

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The sun continually releases

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protons and electrons into the

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solar wind. A spacecraft can

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achieve high speeds by riding

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the solar wind. The spacecraft

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would spin up and deploy ten to

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twenty, multi-strand tethers.

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Each would be positively charged

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and about twenty kilometers long.

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Propulsion results from the

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momentum exchanges of the solar

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wind’s fast moving protons,

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shown here in blue. Thrust is

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created when the positively

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charged tethers electrostatically

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repell the protons.

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The spacecraft's electron gun

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discharges electrons. This

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maintains the correct positive

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bias on the charged wires. The

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team at NASA’s Marshall Space

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Flight Center in Huntsville,

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Alabama is currently creating

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models and simulations and