Officially, Apollo 17, launched December 17, 1972, was the last manned mission to the moon. But in December of 1974, two American astronauts were sent on a secret mission to the moon funded by the US Department of Defense. What you are about to see is the actual footage which the astronauts captured on that mission. While NASA denies its authenticity, others say it's the real reason we've never gone back to the moon.