Eran Arbel, ISF
Scientists as early as the 60s of the last century began to wrestle with the issue of creating a space elevator, a facility that would save many percent of the costs of launching objects into space. According to their calculations, the material needed to build such an elevator should be at least twice as strong as any known material today, including graphite, steel, quartz and diamond.
The writer Arthur Charles Clark recognized the problem of the materials and his genius stood the test of creation. In his 1978 book, Fountains of Heaven, he describes the construction of the space elevator from a continuous one-dimensional quasi-diamond crystal that serves as a cable. To the delight of MDB enthusiasts, the Japanese researcher Sumio Aijima discovered carbon nanotubes, a material with 100 times the strength of steel and one-sixth the strength and high resistance to stress.
As if to bring the science buffs down from the high tree they climbed, calculations recently made by Nicola Fogno of the Polytechnic of Turin, Italy, conclude that the nanotubes will not work.
Fogno claims that a slight flaw in the tube, such as missing one carbon atom, can drop the tensile strength to 70% and materials and a large amount of material made from connected nanotubes lowers the strength to less than XNUMX percent!
According to the calculations, building a space elevator will require a pressure of at least 62 gigapascals. A uniform nanotube can hold about 100 gigapascals but less than that already opens the way to safety issues.
Nanotube enthusiasts claim that building the cable from a large number of tubes in one beam will create frictional forces that will offset the small defects. Creating a uniform nanotube 36,000 kilometers long could also work. But a clear decision will only be possible when Pogno's full calculations are published in the July issue of the Journal of Physics: Condensed Matter.
