A week before the launch of Apollo 11, astronaut Frank Borman approached William Safire, Pres. Nixon's speech-writer, about the possibility that Aldrin and Armstrong might not return to earth after walking on the moon. Safire prepared a speech for Pres. Nixon to give to the nation after contacting the wives and families of the astronauts.
The speech began, "Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace," and ended, "For every human being who looks up at the moon in the nights to come will know that there is some corner of another world that is forever mankind."
Fortunately, the speech was not needed. If you want to read the speech in its entirety, read Almost History by Roger Bruns, page 20.