Larry,

First off I say what I think whether it be to people I am in almost complete agreement (KC and GA), usually in agreement (you in the past) or seldom in agreement. I don't believe in tricks or dodges as my often long winded replies should make obvious. GA can handle disagreement well and agree to disagree in a friendly manner. GA and I have never gotten ill with each other despite some strong disagreement on a few key issues. KC handles almost any disagreement poorly and frankly you seem to have gone from GA status to KC status or worse lately. Try sticking to the facts and areas with room for debate without the insinuation. I am still very interested in your opinions in many space related areas.

Architecture has been defined. You have the 90 day plan which is supposedly NASA's best effort along the Moon first line, Zubrin's Mars Direct plan and the NASA reference missions. I'm not asking to define any missions just compare the ones already out there.

Secondly your comments on Zubrin's cost estimates are really irrelevant. The issue in choosing the optimum path is not absolute cost but relative cost. NASA's reference mission was larger than Zubrin's Mars Direct and made less use of in-situ resources and was estimated to cost more than twice as much (50 billion vs 20 billion). Feel free to jack up Zubrin's plan to 50 billion for comparison purposes if you want to claim cost is primarily in development. I don't remember the per mission cost off the top of my head but I think it was in the range of 2 to 5 billion for subsequent missions for both scenarios. The same group estimated the 90 day plan would cost 400 million. The difference was in avoiding the lunar base costs and using in-situ resources.

These cost can all be claimed to be under-estimates based on NASA's ISS record but it is pure bullshit to claim that the Moon first plan will not cost far more if you comprehend the rocket equation. The number of flights needed for payback on the expensive option versus the cheaper ones also depends on relative costs not absolute ones. Any reasonable person can see the number of flights has to be huge and the residual cost very low to justify that whopping increase in relative cost. Give me your estimate for the percentage of mission cost cut with the long slow option and I'll tell you what the number of flights will be to pay back the huge up front cost if you don't want to do the math. I can derive the equations needed for that in about 5 to 10 minutes.

As for the narrow view Chris's point is valid and I have addressed it as well. Martian resources are more plentiful and easier to harvest. Since they are easier to harvest and more bountiful on Mars less equipment will need to be launched to Mars than the Moon to harvest the same mass of resources. That means less cost to establish operations on Mars from a launch cost perspective. From that point Mars makes a better staging area than the Moon. With Mars you get a good colony prospect and a staging area. With the Moon you get a possible tourist destination and a staging area with less resources. It all goes back to understanding the delta v argument.

There are other ways to look at it off course and I will be glad to discuss any you favor if you'll stick to the technical issues.

Regards,
Mark