Understanding exactly what the Geotail does (something to do with measuring the solar wind's interaction with the Earth's magnetosphere) may require a background in heliophysics.

WSJ: The Charge of the Satellite Brigade | Geek Chic

To date, balloon-borne activities have centered around heliophysics and astrophysics that have not required precision-pointing, says Near-Earth Object (NEO) program officer Rob Landis at NASA headquarters.

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