Re: NASA inefficiency: The hint is in the name
"The engine had progressed to the point where they had successful test stand firings, and were preparing to move to the next phase, building it into a new second stage for the Saturn V."
I remember that mess quite well. It seems that the US and the USSR had a treaty against things nuclear or nuclear looking going into orbit.
Hence, the Congressional cut, abiding by a space treaty that remains in effect today.
I also recall that that particular engine wasn't capable of anything *near* a Mars shot. At all. It'd have made the moon run much faster, but Mars was flat out out of the question.
That all said, we still do have nuclear rocket designs, which are far more efficient and designed to work in microgravity. However, environmental concerns also are important, for who wants uranium spewed on their beaches or their petunia garden?
So, what we *really* need is a rocket that is intrinsically safe, which sounds like black heresy today, but within our technological capabilities.
As for this one, compared to NASA, this is a small shop. Answers will be far more easily available, as one doesn't need to contact each and every subcontractor. The answer is likely simple enough, in terms of engineering. O2 overpressure and failure tends to a rare few methods to overpressure a sealed tank, fire, electrical short inside the tank or placed upon the tank. Heat is the key, as a cryogenic tank doesn't have a pressure increase without a fuckton of heat applied.
Thankfully, rocket science isn't *quite* as hard as it was when we confiscated war booty in the form of German scientists and V2 rockets.
Understood is length of wires, lest they separate under boost. Understood is pogo oscillation. Understood are thousands of things.