Source: SpaceWeather.com
April 5, 2019: NASA’s MMS probes, which use GPS signals to orbit Earth in tight formation, have just shattered the record for long-distance GPS navigation. The four probes recently located themselves 116,300 miles above Earth’s surface, surprising experts who once thought that GPS could function no higher than about 22,000 miles.
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Read More about the The Magnetospheric Multiscale Mission at NASA.gov