The Liftport Group, which is a private company building a space elevator, has received FAA approval for preliminary testing. The company will use a ballon with a one mile high tether to run tests of the lifting mechanisms.
One of several space elevator efforts, the projects will use super-strength carbon nanotube cables that run from the ground to low earth orbit. Centripetal force and counterweights will keep the cable rigid and anchored in one spot. The space elevators will dramatically lower the cost of getting people and materials into orbit.