The sheer bravery of the first men to sign up to go to the moon is outstanding. I remember listening to an interview where Buzz Aldrin said he estimated that there was a 60% chance of going to the moon and coming back home alive. He still decided to do it.

They even wrote a speech for Nixon in case Neil Armstrong and Buzz Aldrin got stranded on the moon:

  Fate has ordained that the men who went to the moon to 
  explore in peace will stay on the moon to rest in peace.

  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.
  
  These two men are laying down their lives in mankind’s most 
  noble goal: the search for truth and understanding.