It has to do with that the expense of setting up a cellular network is so expensive that it hasn't be done in large parts of the earth, much less another celestial body.
That's the business of network providers. To acquire the hardware, install them, and operate the service. That has nothing to do with Nasa or Nokia.
I don't know why there are areas in US that lack service providers. Maybe someone here can explain it - I presume the reason has to do with something US specific about the business rather the overall cost since lots of low GDP areas globally can have good cellular coverage.
It's not so much average earnings per person as average people per square mile. The network providers only want to invest where the return on that investment meets or exceeds some floor. Parts of the US are so sparsely populated the phone contracts for cellular would be huge to justify building the towers and backhauling the signals.
There are so many things named with stupidly inconsistent capitalization that we should all stop caring and just capitalize the first letter like any other proper noun. I often have to google a product or company name to find out the correct capitalization, which is often hard to find because the stylized logo doesn't even use it.
