Question

The space elevator project is an effort that intends to place an elevator system grounded on the Earth into geosynchronous orbit. Carbon nanotubes are the only material strong enough to make this elevator. What is it about carbon nanotubes that make people think this way? Do you think a space elevator is possible? What are some potential issues?

Answer 1

Carbon nanotubes are the only material strong enough to make space elevator because of the following properties:

• higly flexible - can be bent considerably without damage

• very high tensile strength

• very elastic - 18% elongation to failure

• high thermal and electrical conductivity

• low thermal expansion coefficient

• good electron field emitters

The key thing is that the process essentially makes carbon into smoke, but because the smoke particles are long thin nanotubes, they entangle and hold hands. this is actually making elastic smoke, which we can then wind up into a fiber.

Space elevators could lift material at just one-fifth the cost of a rocket, since most of a rocket's energy is used simply to escape Earth's gravity. Not only could a space elevator offer research expeditions for astronauts, the technology could also expand the possibilities for space tourism and even space colonization.

A space elevator - if it ever becomes reality - will be quite long. NASA needs about 144,000 miles of nanotube to build one. In theory, a cable would extend 22,000 miles above the Earth to a station, which is the distance at which satellites remain in geostationary orbit. Due to the competing forces of the Earth's gravity and outward centrifugal pull, the elevator station would remain at that distance like a satellite. Then the cable would extend another 40,000 miles into space to a weighted structure for stability. An elevator car would be attached to the nanotube cable and powered into space along the track.

The biggest problem has always been finding a material that is strong enough and lightweight enough to stretch tens of thousands of miles into space. This isn't going to happen probably for the next decade at least, but in theory this is now possible.