Pop quiz time: what do Tekkaman Blade, Gundam 00, and Battle Angel Alita have in common?
They’re all anime that have space elevators and orbital rings. A space elevator is exactly what it sounds like; a tower that goes all the way from the ground up into geosynchronous orbit, so that you can get things into space on an elevator (or a vertically oriented train) instead of launching rockets. An orbital ring is a structure that goes all the way around the planet’s equator connecting several space elevators.
(Well, the Orbital Ring in Tekkaman actually isn’t as far from the Earth as one should be.)
It might sound like one of the more unrealistic sci-fi ideas out there, but actually, this is one that has been seriously proposed in real life. While building even one space elevator would be by far the biggest construction project in history, it would be such an improvement in efficiency compared to rockets to be ultimately worth it; it costs thousands of dollars per kilogram to lift things into orbit with rockets, while sending something up a cable would be only a faction of that.
The question, of course, is whether a space elevator could be built in the first place. No conventional material is strong enough, but carbon nanotubes or something similar are showing a lot of promise. It’s not entirely clear whether it can really be done, but it’s plausible enough for hard science fiction. (And in fact the first popular depiction of the concept was in The Fountains of Paradise, a novel by Arthur C. Clarke.)
Getting back to anime, it’s interesting that the normal technology in Tekkaman Blade tends to be more realistic than most sci-fi anime, considering how less grounded the Radam and the Tekkamen themselves are.