SSTO doesn't rely on aerodynamic lift, it can fly higher than a lift-based vehicle can to avoid air resistance/heating. I suspect you can fly high enough that burning up isn't a problem, but I don't see how you reach that as a conclusion by analogy to single stage to orbit rockets.
> SSTO doesn't rely on aerodynamic lift, it can fly higher than a lift-based vehicle can to avoid air resistance/heating
The only reason to do SSTO is so you can use an air-breathing engine. That's why practically every recent SSTO draft looks like an airplane.
This team appears to be using a reaction engine for thrust, so I'm not sure how they're planning on dividing the work between buoyancy, lift and reaction. But the whole point of using an airship and making it massive is so it can generate lift in air too thin to keep a metal tube flying.
> don't see how you reach that as a conclusion by analogy to single stage to orbit rockets
Because SSTO has been extensively studied, this is a problem SSTO would have to deal with, and in no case was it a dealbreaker.
