> I want the concept of launching from altitude to work because it seems like the heavy atmosphere part has different requirements and so having another vehicle

> I want the concept of launching from altitude to work because it seems like the heavy atmosphere part has different requirements and so having another vehicle to help with that seems intuitive. This is essentially what multi-stage rockets are. Only the lowest stage is optimized for heavy atmosphere. The "dropping from a plane" thing is theoretically a good idea. Wings and jets save lots of fuel. But in practice one needs a hilariously large plane to carry a modest rocket, and it needs to be hypersonic to really give the dropped rocket a good orbital kick, and the linkage between the rocket/plane needs to not blow up. Historically... You mind as well build a massive vertical first stage. You could strap jets to a first stage and try to reuse it. Hello KSP!