The 31 GPS satellites
Did you know that all GPS satellites are owned by the US?
GPSs are ubiquitous. We all use them, and for us not so geographically astute, perhaps daily.
However, did you know that all the GPS devices in the world use a network of only 31[1] satellites funded and owned by the US Government? Although other countries have similar competitors, such as the GLONASS provided by the Russians (which you can use on products such as your Fitbit to improve location accuracy), the GPS is still the default.
Another interesting tidbit is that GPS chips are built[2] with certain limitations in their use. One limitation is to prevent it being strapped to an Intercontinental Ballistic Missile. The chips are programmed to shut off tracking when the device calculates that it is travelling faster than 1,900 km/h and/or (depending on the manufacture) higher than 18,000m of altitude.
