>I agree that there could be a base built on the Moon - but using the shuttle for that? ummmmm I dunno. First of all you sure as heck are not landing a shuttle on the Moon - plus the shuttles were designed in the 1970's and the ones we have left that have not blown up are beat up pretty good by now. Generally I would be all for retrofitting and updating - but I think the shuttle's time has come and gone.

Let's see... Even if you're not landing the shuttle on the moon.
* You'll need to uprate the shielding == more weight
* Main Engines are only used for launch remain affixed to vehicle and become "dead weight". Extra weight = extra fuel required for trip to moon and back
* Wings are only required for landing. Aside from that, they become "dead weight." Extra weight = extra fuel required for trip to moon and back.
* As stated previously, heavier vehicle equates to more fuel required. Lighter vehicle would be able to carry more cargo per unit of fuel.
* Of course, to also have to get everything into orbit too (if we plan to do everything in one launch). Had Lunar Direct profile been selected instead of LOR for Apollo, it would've required construction of Nova rocket rather than the Saturn V.
* Shuttle requires significant maintenance to become flight-ready again == adding to the operational cost. It's to the point where expendable launch vehicles end up being cheaper. IIRC, it takes two weeks to just deal with the heat shield tiles. The main engines pretty much have to be overhauled after each flight. i.e. it's very far from airliner-type turnaround times, unlike how NASA oversold the shuttle back in the 1970s.
And speaking of airliners... we've got the concern regarding metal fatigue due to pressurization/depressurization cycling during each flight (which was found to be the primary contributor for the loss of early DH Comet airliners). It could only be worse with the space shuttle -- which not only has a much more extreme pressurization/depressurization cycle, it goes through more extreme heating/cooling cycle.