It was announced from Schriever Air Force Base, Colorado, on 19th January that
the 50th Space Wing had completed Phase One of a two phase Global Positioning
System constellation expansion known as ‘Expandable 24’. When fully complete,
this expansion will increase global GPS coverage and provide civil, military and commercial GPS users with more robust satellite availability and a higher
probability of signal acquisition in terrain challenged environments.

The GPS constellation consists of 24 operational slots positioned within six equally-spaced orbital planes surrounding the earth. This plane/slot scheme and enhanced satellite placement ensure GPS users receive the most accurate
navigation data at any time, at any place around the world.