Electromagnetic vehicles traveling along the cable could serve as a mass transportation system for moving people, payloads and power between Earth and space. Current plans call for a base tower approximately 50 kilometers tall, with the cable tethered to the top. To keep the cable from tumbling to Earth, the structure would be attached to a large counterbalance mass beyond geostationary orbit, perhaps an asteroid moved into place for that purpose. The cable is basically in orbit around the Earth. These tracks would allow electromagnetic vehicles to travel at speeds up to thousands of kilometers per hour.
Conceptual designs place the tower construction at an equatorial site.
The extreme height of the lower tower section makes it vulnerable to high winds. In Clarke's novel, engineers built a space elevator on the mythical island of Taprobane, based loosely on Sri Lanka, an island near the southern tip of India. At the moment, Sri Lanka lies between 6 and 10 degrees north. According to Smitherman, construction could be feasible toward the end of the 21st century. In 50 years or so, we'll be there.