The How and Why of Returning to the Moon

"NASA has unveiled the initial elements of the Global Exploration Strategy and a proposed U.S. lunar architecture, two critical tools for achieving the nation's vision of returning humans to the moon.

The Global Exploration Strategy focuses on two overarching issues: Why we are returning to the moon and what we plan to do when we get there. The strategy includes a comprehensive set of the reasons for embarking upon human and robotic exploration of the moon. NASA's proposed lunar architecture focuses on a third issue: How humans might accomplish the mission of exploring the moon."

http://www.nasa.gov/mission_pages/exploration/main/index.html