The article says, &quot;His conclusion: The space elevator could be built with existing technology—minus the super-lightweight tether necessary to make the whole thing work.&quot; In other words, it cannot be built with existing technology.<p>NASA uses the idea of &quot;Technology Readiness Level (TRL)&quot; [1] to help assess speculative technology, the (obvious) idea being that each stage of deployment of a technology relies on passing tests at previous stages.<p>On this scale, it&#x27;s not clear to me that space elevators are at TRL1 (&quot;basic principles observed and reported&quot;) yet. Space elevators depend critically on having a material that&#x27;s strong enough to build the cable. Feasible designs for climbers, debris avoidance systems, power transmission and so on, can&#x27;t make up for the lack of this critical component.<p>[1] <a href="http:&#x2F;&#x2F;www.hq.nasa.gov&#x2F;office&#x2F;codeq&#x2F;trl&#x2F;trl.pdf" rel="nofollow">http:&#x2F;&#x2F;www.hq.nasa.gov&#x2F;office&#x2F;codeq&#x2F;trl&#x2F;trl.pdf</a>