I suppose a space elevator could solve this, b It's not just the 400KM. It's the 400KM + orbital speed. Once you've got that, you no longer need great big fuel guzzling engines to quickly get above the atmosphere. You can start using low thrust but high efficiency engines, like ion drives. Sure they may be slow, but if you aren't in a hurry they'll get you wherever you want. I completely agree with the "nickel and dime" approach. I was not suggesting that we mine the moon for resources. My use of the moon is to give us a stable structure to build a base on. The problem is - it costs an order of magnitude more to reach the moon, and you no more need a "stable base" than you a fish needs a bicycle. You also make your [Mars bound[ space craft more expensive by requiring to boost from the surface of the moon, and by adding the need to endure the [harsher than LEO] lunar tempe True, but when you add in the deltaV to get to the Moon in the first place... plus all the costs associated with getting the base built and supported and boosting the materials and equipment to the Moon... The few tens of thousands of dollars you 'save' in fuel start to look like the chump change they are This is only true if the only thing you're using the Moon for is a fuel depot. Actually building large parts of