When they first started the project to see if it were even possible to send men to the moon there was one major hurtle. A man, James Van Allen, the space scientist, stands in front of the National Academy in Washington, D.C., and announces that they’ve just discovered something new about the planet, May 1, 1958. You see there is these belts of high intensity radiation surrounding the earth. Men can not go through it without lead protection. Feet of heavy lead in thickness. Space craft have to be light to get to the moon and back. Not good. So the wonderfully intelligent blokes decide to see if they can blow up the God installed radiation belts. Didn't work, only added more radiation to an already dangerous barrier to human space travel. This is why living man has never and will never leave earth's near orbit...of course the spin doctors tell another story:
http://www.npr.org/templates/story/story.php?storyId=128170775
Ok... so we can't go to the moon. No problem, we will simulate it and...
http://www.apfn.org/apfn/moon.htm

Possible Motives

Several motives have been suggested for the U.S. government to fake the moon landings - some of the recurrent elements are:

Distraction - The U.S. government benefited from a popular distraction to take attention away from the Vietnam war. Lunar activities did abruptly stop, with planned missions cancelled, around the same time that the US ceased its involvement in the Vietnam War.

Cold War Prestige - The U.S. government considered it vital that the U.S. win the space race with the USSR. Going to the Moon, if it was possible, would have been risky and expensive. It would have been much easier to fake the landing, thereby ensuring success.

Money - NASA raised approximately 30 billion dollars pretending to go to the moon. This could have been used to pay off a large number of people, providing significant motivation for complicity. In variations of this theory, the space industry is characterized as a political economy, much like the military industrial complex, creating fertile ground for its own survival.

Risk - The available technology at the time was such that there was a good chance that the landing might fail if genuinely attempted.

The Soviets, with their own competing moon program and an intense economic and political and military rivalry with the USA, could be expected to have cried foul if the USA tried to fake a Moon landing. Theorist Ralph Rene responds that shortly after the alleged Moon landings, the USA silently started shipping hundreds of thousands of tons of grain as humanitarian aid to the allegedly starving USSR. He views this as evidence of a cover-up, the grain being the price of silence. (The Soviet Union in fact had its own Moon program).