Since GPS satellite positioning information is free to the public, it allows for everyone to take advantage of its uses.

In 1978, the launch of the first GPS satellite saw a revolution in the way position is measured.

GPS satellites orbit at around 12,600 miles, and satellites near the horizon will be a lot farther away.

Just imagine a solar storm taking out two GPS satellites.

None the less, in February 1978, the first GPS satellite was launched.

GPS satellites orbit at an altitude of approximately 20,200 km (12,550 mi).

Almanac data can be received from any of the GPS satellites and is considered valid for up to 180 days.

One such example is with regard to keeping the clocks on GPS satellites accurate.

The GPS satellite positioning system enables calls for assistance even without human involvement.

Durin this time, the top spacecraft will begin to search for surrounding GPS satellites.