Apollo 18

Officially, Apollo 17, launched December 17th, 1972, was the last manned mission to the moon. But, a year later, in December of 1973, two American astronauts were sent on a secret mission to the moon, which was funded by the US Department of Defense. The actual footage that the astronauts captured on that mission has been released. While NASA denies its authenticity, others say it's the real reason humans have never been back to the moon.