firstly thanks for filling me in on his background, and yes none of those points should be show-stoppers. When the lunar mission finally comes about I'll personally be riveted to the internet, as I was with Discovery (just imagine we've never yet seen the lunar surface with high-defn video streamed straight to our PCs ..)

But the impression I got was that you think the problems he raises have all been sufficiently dealt with, whereas although I acknowledge the work of the MS and others, I'm concerned that overall, we actually know a lot less than we think we do, and on a lengthy deep space mission these unknowns could well bite us on the bum and result in catastrophic failure from an unexpected source. I just don't know that we're ready for Mars yet, however of course that doesn't mean at all we should be giving up on it. As Raoul points out the best scenario would be breakthroughs in propulsion, which would shorten trip times not only for the astronauts, but for any further backup or rescue missions ..

Zubrin deals with this by having redundant infrastructure already there on Mars even before human landings, which is very sensible, but my point is that this sort of mission is many orders of magnitude more hazardous than week-long missions to the moon 35 years ago.