LOCKHEED MARTIN, a company known more for its work in aerospace and national defense, is also working on technology that could one day save miners trapped underground. The wireless system, MagneLink Magnetic Communication Systems, has already passed a number of tests using magnetic waves. It has successfully transmitted a signal through mines to a depth of more than 472 m (1,550 ft) and could be certified by the federal government in a matter of months, according to a report by The Wall Street Journal.
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