In message PWWQb.150687$na.257871@attbi_s04, Robert J. Kolker
writes

[snip]

I am very interested in space-based enterprise. Our communication
systems are now dependent on comm-sats. We would be much worse off
without a working GPS. All these unmanned projects are not only
technically excellent, but -they pay for themselves-.

I'm curious here. How does GPS "pay for itself"?

--
Richard Herring