Why reinvent the wheel?
I don't understand why we can't go to the moon with the space shuttle. Its big enough to put a landing module inside. It has enough space inside also to keep the crew comfortable and fed as well as excercise. It has a built in rocket system that should be powerful enough to enable it to escape Earths gravitity. I'm sure you guys will be able to explain why it's a bad Idea. But before you do, just imagine this: you are a scientific team leader given this problem to solve (a manned flight to the moon) and you have to do it with what we have on hand (the space shuttle).