Don!   "OMMMMMM"

Cars that can release in an emergency at atmospheric elevations and glide to a safe landing. It might even serve as a launch point for cargo and passenger transport.

Other than the above mentioned cars/gliders an aero defense no-fly zone of say 500 mile radius protected by energy weapons (lasers, etc.)

Tether point would have to have redundant attitude adjustment capabilty. Didn't Clarke suggest marshalling an asteroid into the geo-sync position?

Lot'sa opprotunity here. Unite Mankind, eventual total population control and monitoring. Exploit "heavenly" resources. I suggest we call it "Babel".