That being said, they are doing and planning phenomenal things, and SpaceX success can only help the space exploration industry.

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I'm a little concerned about the 48 Raptor engines on one stage. That is a ****load of parts that have to work in perfect symphony EVERY TIME or you're going kaboom. It's more aggressive than the Soviet N-1, and we all know how that one turned out...

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I thought the same, but maybe it's not so crazy. If I recall my engineering statistics right, the predicted reliability for a system working in parallel is:

P(system_reliability) = P(component_reliability)^Number of components

I believe that the risk tolerance for spaceflight is something like 99% reliability of no catastrophic failure. Note: commercial air travel is like 99.999%. So, if SpaceX can tolerate a 1% chance of catastrophic engine failure, then the individual engine reliability needs to be:

P(component_reliability = (0.99)^(1/48) = 0.9979

I don't think 99.79% reliability is too crazy. The much more complex Space Shuttle Main Engine demonstrated 99.75% operational reliability and zero catastrophic failures. SpaceX is getting tons of operating data thanks to their 9 engine configuration on the Falcon 9 and they tend to use relatively low chamber pressures in their first stage engines. This gives them a good chance to observe out-of-design conditions and perform an orderly shutdown before an engine fails catastrophically.

The vision itself is one of those things that would be categorically insane 10 years ago, but now seems faintly achievable given their progress in the last 10 years. I fully expect it will evolve in form/function and take longer than expected today. But, sometimes you achieve way more by staking an ambitious vision than just trying something incremental like Boeing's vision.

Pretty fascinating stuff and glad to see any form of movement to Mars within my lifetime.

I liked his analogy to Union Pacific. SpaceX will get you to Mars, you have to figure out what to do when you get there.