I can't see how a moon landing would be dramatically more expensive than any other mission. Each current mission usually involves a payload bay full of stuff developed for that trip. This would be no different.
Do we really know everything there is to know about the moon? We have physically explored it for a grand total of a few days. Imagine what results drilling could produce. We learn tons about the earth from drilling.
Its a matter of fuel mostly, and would probably require some major edesign of the Shuttle, like the fuel system (You'd probably need to keep the external fuel tank for the majority of the flight, and that would have to be modified, yadda yadda..). You'd need to accelerate the shuttle from a low earth orbit, to escape velocity, which is not a trivial matter for a vehicle of that weight. I dont know the velocities and masses off hand, so I couldn't do the calculations.
What you could do is use "off the shelf" shuttle parts and perhaps construct a vehicle to go there. No need for the wings to make the trip to the moon, amongst other things.. I am sure some rocket heads have been thinking about this already.
(I believe Right Whale is a space nut, so I've flagged him on this post, maybe he could add something.)
There are several problems with sending a Shuttle to the Moon. Most significantly, when the Shuttle reaches orbit, it has no fuel to thrust its way out of low Earth orbit. Thus, you would need another, separate booster, fully fueled, in orbit already to strap on to the Shuttle.
I assume that you would want to make this a round-trip. That brings up your next problem -- even if you simply looped around the Moon (the lowest fuel-cost option), you would need to re-enter Earth's atmosphere to slow yourself down on the way back. Although hypersonic re-entry flight with the Shuttle has been demonstrated from low Earth orbit, coming back from the Moon, you are traveling half-again as fast as in low Earth orbit. It's not clear that the Shuttle could withstand those temperatures on aerocapture.
Best solution? Assemble a Moon craft in orbit, using Shuttle to transport from Earth to orbit -- and no further, as it was always intended to do.
Use of STS in it's extended duration mode causes substantial tradeoffs in cargo capacity. The pallets required to extend the orbiter to such duration exist, but they are really designed to function in conjunction with a low-earth orbit mission.
In the late 1980's NASA had developed a heavy-lift launch vehicle concept called Shuttle Z. Shuttle Z featured an extended external tank which could provide additional fuel to the system. To send an orbiter to the moon essentially requires a doubling of the velocity of the spacecraft, which is more than double the mass of the fuel to send the system to low-earth orbit.
Moreover, the orbiter main engines are not designed for reignition on the same flight. The engines are designed for one time use and shut-down during any one mission. The refiring of SSME's is hypothesized, but the flight rating needs to be upgraded to permit refiring on the same flight. Interestingly, the SSME's are refired on multiple missions after inspection. Production of SSME's for such reuse would be possible with more extensive testing and design of the engine. NASA would need to make such R&D a priority.
Shuttle Z required the orbiter to be inserted into a higher orbit and then fire the main engines to insert the package into translunar flight. Refiring the SSME's in lunar orbit would be required at least twice. Once to slow the trajectory and permit the moon's gravity to catch the spacecraft and a second time to return the spacecraft to Earth. The injection of the package into trans-Earth flight would require substantial fuel because the orbiter is substantially larger than the Apollo C/SM.
Now we're going to start Lunar Warming!!!
"But Wendell Mendell of NASA's office for human exploration at the Johnson Space Center in Houston contends that public efforts will make it to the Moon before commercial endeavours, and cites European and Japanese trips scheduled for the next year."
Yeah, Wendell, keep cheering on those "public efforts." We were on the moon what, 30 years ago? Haven't been back since. And then he cites the success of "foreign" "public efforts." We were way ahead of the curve and now we can only point to the successes of other governments because govt. employees like him seem to be completely content sitting on earth collecting a "public" paycheck.
What a knee-jerk socialist response from our space agency. Instead of promoting a US company's efforts to explore space (NASA's mission), he tries to downplay it -- by pointing to the success other government's are having. What a moron.