Dark Moon Rising: Archibald space TL

[Archibald]

No, sorry: I meant that even a primitive rocket was faster than that airbreathing record. It's pretty easy to go fast with rocket power but ballistic range is a b*tch. Pointy.

 

[Scott Kenny]

There were proposal for air breathing rocket engine
from insane line NULACE to whatever power HOLOT
Now a china company try that with Ramjet power by air and output engine gas generator...

Source: https://www.secretprojects.co.uk/threads/chinese-space-program.5642/post-728089

That might be simple enough to work. Rocket-based combined cycle engine.

Especially if you turned whatever optimizer loose on the thing that simplified the SpaceX Raptor engines.