Wow, that's ... ambitious. I'd imagine the extra mass to make an energyia-size tank+engines able to land horizontally to be enormous. It's not just wings (plus

Wow, that's ... ambitious. I'd imagine the extra mass to make an energyia-size tank+engines able to land horizontally to be enormous. It's not just wings (plus folding mechanism, if you believe that's worth saving a bit of drag on the way up) but also landing gear plus all the structural strengthening required. Sounds suspiciously like one of those projects you propose when you want something finer short term but assume that they never survive to the point where they actually need to deliver?