We live at the bottom of gravity well that dictates design, similar to Feynman’s quote- “For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.”
This means that no matter how many sci-fi movies portray SSTO and no matter how many NewSpace infomercials scream cheap, “there is no free lunch.” By the way, the other famous Heinlein quote about Earth orbit being “halfway to anywhere” was revised to “Low Earth Orbit” as a NewSpace marketing ploy – He never said LEO and may just as easily have meant GEO.
LEO is not really space and is a dead end.
To achieve escape velocity (not so much orbital velocity) hydrogen upper stages are almost a necessity. To go anywhere Beyond Earth and Lunar Orbit (BELO) with humans requires massive shielding and chemical propulsion will not work. Only nuclear energy can push such mass (until some kind of beam propulsion infrastructure exists). That said, the only practical form of nuclear propulsion is “pulse” or, to put it bluntly, bombs.
This means that inside the Earth’s magnetosphere only chemical propulsion is practical due to fallout eventually being sucked into the atmosphere. This works out fine because just outside the magnetosphere is the Moon and that is where we have to go for the water-as-radiation-shielding anyway.
To keep this as short as possible, only progressively more powerful iterations of a Super Heavy Lift Vehicle used in a state sponsored public works project to develop a cislunar infrastructure has any chance of success. NewSpace is a scam that ends in the dead end of LEO.
And that makes their flagship companies inferior lift launch vehicle a hobby rocket.
NewSpace has been doing one thing for years yet nobody ever talks about it: the Ayn-Rand-in-Space Musk groupies damn the space agency and cal for it to be done away with on one page and praise NASA for pouring several billion tax dollars into commercial cargo and commercial crew on another.
They have nothing bad to say about the over one hundred billion dollar space station to nowhere yet curse all government “porkonaut projects” not connected to SpaceX (like the SLS) as pure evil. If these two-faced deceivers were not so damaging to the future of space exploration their idiotic contradictions would be funny.