NAVSTAR

From DictionGloss

The name given to the American GPS satellite constellation. NAVSTAR is an acronym for NAVigation Satellite Timing and Ranging. The fully operational constellation is composed of six orbital planes, each containing four satellites. At present, a total of 27 healthy satellites are aloft in the NAVSTAR system; the full complement of 24 and 3 additional satellites to be used as spares. Follow-on satellites are constructed and awaiting launch as needed or desired.