It seems unlikely that an orbital ring will be the first profit making venture of a lunar colony. --Farred 18:51, 31 July 2010 (UTC)
Here is a likely addition
== 20,000 Cables into the Sky ==
A carbon fiber epoxy composite cable suspending its own weight in one Earth gravity will break under the load if it is eighty kilometers or more in length. Since the orbital ring is specified as being at ninety miles, one-hundred-forty-four kilometers a method of avoiding this problem is needed. That method is tapering the cable. A cable under a twenty metric ton stress at half of its breaking stress at the Earth's surface would need to be three-hundred-sixteen millionths of a square centimeter in cross section, seven-hundred-nine hundred-thousandths of a centimeter in diameter. At an altitude of four-hundred meters it would need an additional three millionths of a square centimeter cross section. By the time the cable attaches to the orbital ring at an altitude of ninety miles, it would need to be one-hundred-fourteen ten-thousandths of a centimeter in cross section. --Farred 14:02, 2 August 2010 (UTC)
Of course, we want to find new materials for cable. It seems that carbon nanotubes would do the trick...
Perhaps I can adapt the wikipedia article on the space Elevator.--Jose Giraldez 02:54, 17 April 2012 (UTC)