[Spaceships] getting into orbit without superscience?

[malloyd]

Originally Posted by Rupert

You see, having a barrier between the energy source (fuel) and the propellant limits how hot you can run the rocket to what that barrier can handle.

This is why *all* reaction engine designs have trouble getting into orbit. Chemical rockets already run hot enough containing the exhaust is an issue. So there's not a lot of space for going hotter (the requirement for better fuel efficiency), which combined with the issue that heating by something other than reaction in the fuel adds weight for both the heat source and heat exchange system, means there really isn't lots of room for improvement even in theory.

The truth is that even a lot of spacecraft engines and power plants that aren't "officially" superscience really are, it's just the required superscience is the somewhat invisible "requires parts that still work at temperatures too high for chemical bonds to exist".