Larry,

The conclusions were those of the investigating committee according to Oberg not mine. They were also in the article I referenced before you made your first post. The difference in a human and robotic mission is economy of scale something engineers working in the real world understand. The cost of engineering time to check a fuel line design is roughly the same whether the total mission cost is 1 billion, 20 billion, or 100 billion. The higher the total mission cost is, the less incentive there is to cut corners for minor savings compared to the total mission cost.

The point of my Apollo example apparently escaped you. Apollo was a success with regard to the clear goal of landing a man on the Moon (the mode I want to see for Mars). It failed as an incremental step to anything else (the mode you prefer). Breaking down a big problem into smaller ones is a standard engineering approach. It is obvious that the Moon program should have consisted of discrete incremental steps in technology and a Mars mission could include testing steps involving the Moon as I have said many times. The point is Apollo's intermediate steps were of direct value to the final goal because it was clear. They did not waste a lot of money on intermediate designs of no value as NASA has for the last 30 years with an approach similar to what you seem to be recommending.

Not setting a worthwhile goal or pursuing goals because they might be of value in the future like we have for the past 30 years is a prescription for wasting money for additional decades.

What you also seem to ignore is the vast difference between the knowledge gap we have with regard to getting to Mars compared to the one we had for getting to the Moon when we committed to that goal. You have pointed out a lot of realistic gaps, but these seem small to me compared having basically no knowledge in these areas at the start of Apollo. Why should we have less confidence we can overcome these obstacles than we had in the past? The past decade has shown America is still a technology leader.

Regards,
Mark