By Dr Tony Phillips – Re-Blogged From Space Weather
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.
“When we began the mission, we had no idea high-altitude GPS would be such a robust capability,” says Trevor Williams, the MMS flight dynamics lead at NASA’s Goddard Space Flight Center.
Above: an artist’s concept of the 4 MMS spacecraft
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