[elteto]

> The rocket equation is a harsh mistress

Love this, totally making it mine ;) Also, there is the problem of efficiency loss due to over/underexpansion as you switch from atmospheric to vacuum conditions, and I have never heard of a rocket engine with variable nozzle geometry to compensate for it.

[schiffern]

That was the promise of aerospike engines, but they have their own problems.

https://en.wikipedia.org/wiki/Aerospike_engine