Space elevator

Just imagine a space elevator that brings us in a few minutes on the moon. Is that possible?

Potential

A space elevator or even a moon elevator could bring down the price of transport for one kilogram from around 50000 dollar to about 200 dollar. This would make space experiments much easier because more convenient. In addition to that there is also the possibility to use it for space tourism. But at first we have to solve the following five problems.

Structure

Material for the robe

Probably the biggest problem is that there are enormous forces, the NASA calculated a value of 62 gigapascal, they effect on the robe so a normal steel robe would tear in a height of 5 or 6 kilometres. Heavy duty steel with tear strength comparable with the tear strength of Kevlar could increase this value to 30.

Another candidate for a material is nanotubes with tear strength five times as much as the one of Kevlar. But the problem with nanotubes is that the tear strength of a complete robe diminishes 70% in contrast to the tear strength of a single nanotube because of mistakes in the crystal structure they aren't preventable. As a result of this a robe made out of nanotubes could only endure 30 gigapascal. Another problem is that carbon nanotubes oxidate and erode in the space to they have to get plated which is again new weight the robe has to carry.

The most promising material is Graphene. This material has tear strength of 125 gigapascal so it would crack in a homogenous gravitation field in a height of 5655 km. But because of the declining gravitational acceleration the braking length increases. If the robe then had a length of 143780 km the robe would be in a complete balance with the rotation of earth and the gravitational acceleration.

Erection of the robe

This problem isn't that unimportant as it seems to be. The idea is to throw such a long robe from a satellite down to the earth station.

Base station

Also the base station has to stand 62 gigapascal which demands a very deep and complex stay into the earth.

Energy supply of the elevator

There are a few concepts to supply the elevator itself with energy because a normal charger is unrealistic because of the high resistance of a 140000 km charger.

A much better idea is to use a laser that is pointed on a little solar cell on the elevator. Another idea is to use solar cells to collect the sun energy in the space. There are several other technologies including little nuclear reactors under the cabin or microwaves they are pointed to the elevator.

 

Conclusion

Considering all these information I think that such an elevator isn't complete fiction and we will be able to build one in the next 100 years but maybe we will not build it because it would cost hundreds of billions of dollars