So, we're going to launch all the assemblies to build one of these things via conventional vehicles, land them on the moon, then assemble it there, where we will use it to put raw materials into orbit around the moon, then rendezvous with them via some sort of conventional vehicle, collect the materials, and from moon orbit, head off to Mars.
Right.
Sidebar: Unless you think you'll save a massive amount of money by mining and refining materials on the moon, what is the purpose of launching stuff into space, slowing it down to land it on the moon, relaunching it into moon orbit, then escaping from moon orbit to head off into space again? Why not just launch it into space from Earth and keep going? Or, if there's some benefit in collecting material at the moon before heading off into space, why not just stay in moon orbit and collect it? At that point, why bother with the moon? Why not just aggregate it in Earth orbit before heading off?
As for using the tech in an Earth-based launcher, imagine uncorking one of these vacuum tubes to the atmosphere just as the projectile gets to the end. Said projectile would have to be going not just fast enough to achieve orbit, but fast enough to achieve orbit after all the velocity it would lose going up through the atmosphere, encountering the densest atmosphere when it is going the fastest. Maybe if we can think of good reasons to send a bunch of tungsten slugs into Earth orbit, and don't mind insane shock waves at ground level...
Right.
