Here is a glimpse at what might have been...

This one of a kind document was written for President Richard Nixon in 1969 in the event that the Apollo 11 astronauts were stranded on the moon.

It was written by William Safire, presidential speechwriter, author and journalist, who died on Sunday (September 27) from pancreatic cancer, aged 79, according to the Boing Boing website.

"Fate has ordered that the men who went to the moon to explore in peace will stay on the moon to rest in peace," it reads.

"These brave men, Neil Armstrong and Edwin Aldrin, know that there is no hope for their recovery. But they also know that there is hope for mankind in their sacrifice."

President Nixon meets the Apollo 11 crew

Apollo 11's third crewman, Michael Collins, is not mentioned - perhaps as it was assumed that he could pilot the Columbia module back to Earth safely.

In a note written while he was alone aboard Columbia, and Armstrong and Aldrin were on the Moon's surface, Collins wrote:

"My secret terror for the last six months has been leaving them on the Moon and returning to Earth alone; now I am within minutes of finding out the truth of the matter.

"If they fail to rise from the surface, or crash back into it, I am not going to commit suicide; I am coming home, forthwith, but I will be a marked man for life and I know it."

Fortunately, the brave Apollo 11 crew returned to Earth safely, and the rest is history.

Click here to find out how you can own the personal NASA flight suit worn by Michael Collins after his recovery from the Apollo 11 mission.