

Constructing an Orbital ring and then using that to get a form of space elevator built.
Totally possible to build with our current technology but the cost if we do it pre space elevator or similar is pretty insane.
Building a ring let’s us basically have a stable space side anchor at low earth orbit instead of geo sync ish like you need for a normal space elevator to match ground speed.
Even more fun is cost for additional rings drops massively and you can build them in different orientations you can get space elevators to rings without having to be on the equator.
https://www.youtube.com/watch?v=LMbI6sk-62E
Last and my favorite part is the possibility of having literally trains that go up to a ring cross an ocean and go back down. Wouldn’t be faster than planes but massively better cargo capacity and efficiency as well as comfortable for passengers.
As AAA said in a comment beside me it isn’t so much that I expect it would predate a space elevator. Simply that it is possible with current tech rather than still waiting on additional moderately likely breakthroughs like long chain carbon nanotube tether.
Also there are plenty of options to have the vast majority of the material be from space and not the surface since the core idea is a metal like copper being spun above orbital speed after being made into a full loop then used for the mag lev to keep at ground speed. There are absolutely a lot of astroids that might allow for that.