All phones are satellite phones, already.

[FoxtArt]

It may be possible for a few cell phones, but satellites do not have the data capacity to handle even 0.01% of them. That's why Iridium calls are so expensive, and why satellite internet is always capped on low bandwidth.

PS: Satellites do not actually send GPS coordinates to your phone. They basically just scream EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE and your phone, like listening to a passing train, uses the Doppler shift effect to figure out the location of the satellites, then triangulating between multiple screaming satellites without any real data transfer, and figuring out it's own location by figuring out the location of the satellites in reference to itself.