Is a Space Elevator Possible ?

  

   New developments in nanotechnology have scientists hopeful that the idea of a space elevator should no longer be relegated to the imagination of futurists and sci-fi authors. In fact, several organizations, including NASA and Google X, have recently investigated this latest vision of rocket-free space flight. It is technically possible that we can use Earth’s own rotation as a means to deliver people and cargo to orbit. By constructing a tether 60,000 to 90,000 miles (96,000 km to 145,000 km)long, with a counterweight at one end and the other anchored to a point along the equator, we could theoretically use Earth’s approximately 1,000 miles per hour (1,609 km/h) rotational velocity to keep the tether suspended (just as a rope with a rock tied at one end remains taut as you spin it around). This tether could then act as a conduit for sending elevators up and down.

    Any cargo released at a high point along  the elevator would remain in orbit. While theoretically possible, there are several problems with this approach. The biggest is tensile strength: A long enough cable will break under its own weight. Steel cables falter under their own weight at about 15 miles (24 km); Kevlar can hold up at about 10 times that length, but still well short of the 60,000 miles (96,000 km) required for a space elevator. Materials engineers are placing their hopes in carbon nanotubes, tiny carbon structures that, when woven together, exhibit enormous tensile strength. But engineers aren’t yet sure how to manufacture a nanotube tether (and even if they could, it’s not clear that it would be strong enough to support a space elevator). If they can build a strong enough tether, engineers will still need to overcome additional barriers, including how to avoid meteorites, space junk, and the inevitable swaying that will occur as a craft inches up the tether and drags against Earth’s natural rotation.

   Despite the barriers, the potential of a space elevator remains alluring. Sending a payload into orbit is currently an expensive and inefficient undertaking. If we could do away with the rocket itself, then (relatively) cheap exploration of our solar system could be within our grasp