>>20986404at sea level nasa tells will perform at reduced efficiency. "rocket engines will be grossly overexpanded during startup in an atmosphere"
at a certain (unspecified) altitude "X", a rocket will perform at optimal 100% efficiency
this is only achieved once in any flight when the atmospheric pressure equals the the pressure at the rocket nozzle.
again this is official nasa data
nasa then tells us that rockets will start losing efficiency at high altitudes (unspecified)
they call this "underexpansion"
in pic we only see that the rocket is only at 70% of its thrust potential with 30% doing no work for the rocket at all
what nasa doesn't tell us is what will happen in a vacuum. if the logic above is followed through to the end the rocket will keep losing efficiency as the atmosphere gets even thinner
(at 100 km air density is 2.2 million times thinner then at sea level)
if so this may be an insurmountable boundary of aerospace physics, perhaps. is the 'root cause' for nasa's very existence- milking the publics belief in the feasibility of space travel with what is essentaill a galactic ongoing "hollwood" movie
