A Lunar Space Elevator would be the biggest structure ever made in much the same way as the Great Wall of China is bigger than a kiddie sandbox. The current prototype design (scaled for a deployment in a single SLS launch) would involve 270,000+ km of tether material, stretching from Sinus Medii, past the Lagrange point, deep into cis-lunar space. With all of that string, the prototype payload mass is only 128 kg, but you have to start somewhere, and it could be (and, if it works, would be) built up over time.
The goal is to open the Moon up to mining. Let the games begin!"
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