That according to Sander Olson’s interview of space elevator expert Dr. Brad Edwards (H/T Brian Wang). Highlights of the interview:

Small quantities of some nanotubes have been made that are sufficiently strong to be used in a space elevator. We would obviously need to produce hundreds of tons of such nanotubes to build a space elevator. With sufficient funding, we could create a nanotube-based material appropriate for a space elevator within a couple of years.

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Nanotubes of lengths up to an inch can already be created. These materials can be bundled together to form arbitrarily long lengths of cable that would be appropriate for a space elevator. So the primary problems at this point are not technical but rather economic and political.

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For a 20 ton climber, a 20 megawatt laser would be needed. Boeing has already demonstrated thin-disk solid state lasers that are 50% efficient, and Boeing is capable of bundling these lasers together to create a megawatt laser today. So by employing 20 of those megawatt lasers in concert we would have the requisite laser power.

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The initial stage would require 4 launches of a heavy lift, Saturn V class rocket. After that it would take several years of sending up climbers. The initial rocket launches would put up two 10 centimeter ribbons. The climbers would attach additional ribbons, like a spider spinning its web. There are scenarios for 8 launches, but the general concept is similar.

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The entire process of building and deploying could be done within a decade. Initial estimates are that it would cost $10 billion to build. Even assuming cost overruns and delays, the project could be built in a dozen years for not more than $20 billion.

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Given sufficient funding, I am confident that the space elevator could be up and running within 15 years. There are no insurmountable technical issues to the concept. The show stoppers at this point are funding and support. This is unfortunate given that the space elevator has the potential to reduce the cost of getting to orbit to perhaps $20 per pound, including human passengers. The space elevator, more than any other project or concept, has the capacity to quickly open up the field of space and create a massive space-based industry.