Hi Guys

Thanks for the spirited defense Mark.

GB has good points of course.

First, I will note that your facts are not strictly facts (believe me, that's an understatement).

"FACT 1: Fuel fom the Moon might be easier to send to Mars, but we can make it there anyway! And make it easier... especially if there is no water at the poles - the "hydrogen" could be certain minerals that mimic its signature, for example. But first and foremost on Mars all that's needed is a pump for air and a Sabatier reactor, plus a bit of hydrogen."

Ah, the "little bit of Hydrogen" was 6 tons I believe. Here's an actual fact Hydrogen is not a dense material even as a liquid (or even as a solid it's not significantly more dense). A cubic meter of liquid hydrogen weighs about 70 kg.
6 tons of Hydrogen is not a little bit: if you divide 6000 kg by 70 kg you get about 85 cubic meters. Roughly, that's the size of a school bus.

Reply: This I know GB and I never said it wasn't a problem, but it's doable. Point is Mars doesn't need Moon fuel. The OutPlanets and the 'roids might but not Mars.

"FACT 2: There is no aerobraking available on the Moon and so in energy terms it costs more to land there and pick up fuel. Perhaps it could be catapulted into orbit via a base but that's a VERY advanced base needed before we get to Mars."

You wouldn't land your Mars spacecraft on the Moon- that's foolish. You would get the fuel for the Mars spacecraft delivered to orbit. And I would never suggest that NASA (or any govt agency) mine lunar water. NASA would simply buy rocket fuel which is delivered- so your fact of no atmosphere on the Moon [so you can't use aerobraking] is irrelevant.
How the fuel is delivered also isn't relevant. The fuel wouldn't even need to come from the Moon (it could come from NEOs or even Earth) NASA would simply buy the fuel which was offered at the best price.

REPLY: Delivery from any where costs in so many ways. Economy requires minimising the deliveries and on-orbit refuelling is an untried technique - that probably needs artificial gee!

"FACT 4: Who needs zero-gee??? Just spin two components via a tether and you have artificial gravity. Or make it big enough to rotate at 6 rpm (humanly adaptable rev rate based on actual studies done) - that's a 25 metre radius for Earth gee, or just 10 metres for Mars gee. Easy!!"

Well, if you have an "unlimited" supply of rocket fuel available at say L1, it might be easier to simply get to Mars quickier.

REPLY: A preferred option but requires a lot of infrastructure. Good for developed Mars Bases NOT first missions.

Artifical gravity might be a solution but it's not necessarily a easy solution- no space station has used artifical gravity- if it truely was easy, then both the Soviets & USA were stupid or there were some real problems associated with using artifical gravity.

REPLY: Docking difficulties spring to mind, but for Interplanet transit that's not an issue. There are no problems that can't be solved if we try. And I don't think Mars gee will be that hard.

The Mouse-Sat (or whatever) mission will hopefully gives us some data on development of mammals in Mars gee.

Thanks for the discussion guys.

Adam