| Well, it starts at "Not actually as bad as I thought", especially when using ISRU; to actually very cheap indeed if you build local infrastructure. (eg. linear accelerator direct to earth's surface is an actual realistic option). [Assuming people invest in infrastructure], In the mid- to long-term you might be able to ship goods to earth from a moon based factory cheaper than you could from some earth-based locations. This isn't really anything special about the moon either, mind you. It's the facts that: * In comparison, Earth has extremely strong gravity; * Gravity effects compound. To get some intuition, look at a Saturn V.
https://upload.wikimedia.org/wikipedia/commons/b/b2/Saturn_v... To get to the moon from earth, you need the whole thing. To get back, you just need the top half of the lunar module (to get to lunar orbit) the service module (to get to reentry) and the Command module (to survive the reentry). A tiny part of the entire assembly! (purists might point out that the system could be rather smaller if there was no intention of a return mission... which is fair enough. It's just to get an initial intuition across here!) |
