[JimmyH155]

This idea is old hat. They have pinched the idea from Kim Stanley Robinson's books "Red Mars, Green Mars, Blue Mars." It is a ripping good yarn and I recommend it to all astronomers. It concerns the doings of the first 100 settlers on Mars. They capture one of Mars' satellites which is made of chrondite (a form of carbon) then they send up robots to turn the chrondite into carbon fibre tube, 9 metres diameter, then lower it to the surface.
Of course the inevitable happens and they have a war, and someone disconnects the elevator at the outside end and it comes crashing down to Mars and wraps itself around the equator. Hits so hard, that the carbon turns into buckey balls and diamonds. Ripper of a story