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Periodic Graphics

Periodic Graphics: The science of space elevators

Chemical educator and Compound Interest blogger Andy Brunning explores what kinds of materials we would need to build an elevator to outer space.

by Andy Brunning, special to C&EN
June 29, 2024 | A version of this story appeared in Volume 102, Issue 20


Infographic on space elevators and the materials that could make them a reality. 
Space elevators are a hypothetical way of getting cargo and materials into space without rockets. Theoretically, a space elevator would consist of a cable (tether) attached to Earth’s surface and extending into space. Elevator cars (climbers) would travel along the tether.
The crucial element of the space elevator is the cable, which would require a material of low density and high tensile strength. The competing forces of gravity and centripetal force would hold the cable upright and under tension.
The tether material would need to be made of a continuous molecule, or single crystal, for maximum strength. And the 100,000 km cable would need to be manufactured quickly—ideally faster than 1 m/s.
Three materials are strong enough for a space elevator tether: carbon nanotubes, graphene, and boron nitride.
So far, the candidate materials’ maximum single-crystal lengths are well below the lengths needed. Polycrystalline graphene can be manufactured at lengths up to 1 km and, while not as strong as single-crystal graphene, may still be strong enough for tether material.
Credit: Andy Brunning

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References used to create this graphic:

Nixon, Adrian, John Knapman, and Dennis H. Wright. “Space Elevator Tether Materials: An Overview of the Current Candidates.” Acta Astronaut. (2023). DOI: 10.1016/j.actaastro.2023.04.008.

Qiu, Tian (Autumn). “Space Elevator: A Lasting Dream for a Sky-Reaching Tree.” Sustainable Nano (blog). NSF Center for Sustainable Nanotechnology, April 1, 2014.

Smitherman, David V., Jr. “Critical Technologies for the Development of Future Space Elevator Systems.” Paper presented at the 56th International Astronautical Congress, Fukuoka, Japan, October 2005.

A collaboration between C&EN and Andy Brunning, author of the popular graphics blog Compound Interest

To see more of Brunning’s work, go to To see all of C&EN’s Periodic Graphics, visit



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