[Bruno]

Mythbusters also took a shot at Lagâri Hasan Çelebi, but really there were problems with both the Ming Dynasty Astronaut and Lagâri Hasan Çelebi's vehicle, even beyond the propellant question.

The Ming Dynasty Astronaut's "vehicle" was said to be a throne. It was going to flip over and smash even if it didn't explode. Lagâri Hasan Çelebi's vehicle is pretty sketchy in description, but generally is agreed to be a sort of open-topped barrel-type thing... which is neither aerodynamic, nor air-tight, and he was supposed to stand in it so even more unstable there. So both are (as originally told) pretty mythological (Çelebi's "parachute" is about as plausable as Icharus' wings too) even assuming modern motors.

The mythbusters used modern motors for both tests, btw, because of health-and-saftey concerns, not that this stopped the Ming Dynasty Astronaut test from exploding - they were not made to be packed in something like a 16x16 grid under a wooden throne with basically-simultaneous ignition.

Both stories, however, highlight the problem that the rockets are really only one of the problems that a TL 4-ish astronaut is going to struggle with. You need an aerodynamic stable body that isn't going to just flip over in flight, you really want to have some control over it beyond "light the fuse and pray to the deity of your choice", it has to be air tight, and you need to somehow bring enough air that your crew doesn't promptly suffocate (or you need a chemical air scrubber, which is even more technology and weight).