EP,

I appreciate your effort to provide concrete issues to debate and I owe you a more detailed reply which I will work on this weekend. There are some seemingly serious issues raised in some of the links you posted. Word of warning though, you should have read everything in the websites you post. There's a whole lot of support for my position that the engineers disagreeing with Zubrin are making different assumptions or setting different goals that have no more or less validity than Zubrin's. I'll glady repost in hyperlink form to make it easy for others to read. You posted a link to a long discussion where it was clear everyone was mostly guessing. Some of the seemingly most daming stuff is from journalist who don't know what they are talking about. Do you really want to rely on the arguments of a journalist who thinks space exploration is useless? For every technical doubter there's an equally technical supporter. I'm truly looking foward to replying in more detail, but wanted to give you a chance to provide some more challenging material perhaps written by engineers. At least one of the journalists is highly qualified based on association with NASA and poses the most serious challenge, but I'd expect based on your comments on engineering expertise to have something detailed from an actual engineer. While I don't believe in arguements based on authority, you'll probably find I'll have a harder time providing counter arguements to aerospace engineers. I actually have to catch up to their knowledge base. Journalists are not engineers and have a haeder time understanding engineering arguements.

My compliments on keeping it civil by the way. I'll try to be less snarky than usual in return.

Regards,
Mark