Buzz Aldrin walks on the moon during the Apollo 11 mission. (Neil Armstrong/NASA/AP)
James Mann, the author of “Rise of the Vulcans: The History of Bush’s War Cabinet,” is at work on a book about Dick Cheney and Colin Powell.

America’s landing on the moon stands as such a stunning success that, 50 years later, we have trouble imagining it could have gone terribly, tragically wrong.

But in the days before the landing, on July 20, 1969, there were acute fears of a mishap. Officials in the White House and at NASA laid out lugubrious contingency plans in case astronauts Neil Armstrong and Buzz Aldrin landed on the moon, but then were unable to get off the surface and back to the space capsule. If that had happened, they would have been doomed to die there, either by slow asphyxiation or perhaps by suicide.

The White House chief of staff instructed William Safire, then a White House speechwriter (and later a New York Times columnist), to draft a remarkable speech for President Richard Nixon to deliver to the nation if the astronauts were stranded on the moon. Along with the speech, Safire included instructions for other actions that should be taken. In particular, he wrote, Nixon should telephone the wives of the astronauts, whom he chillingly referred to as the “widows-to-be.” At a certain point, NASA would “end communications” with the astronauts, Safire wrote, and a clergyman should then conduct the equivalent of a burial at sea, ending with the Lord’s Prayer.

Safire’s undelivered speech lay hidden for nearly three decades before I found it. In the late 1990s, researching a book on America’s opening to China, I was rummaging through the archives of the Nixon administration (then in College Park, Md.) when my eyes suddenly fell on something I wasn’t looking for. It was a memo from Safire to White House Chief of Staff H.R. Haldeman titled, “In event of moon disaster.”

The short text still brings tears to the eyes. It begins, “Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace.” It ends with the words, “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.”

What Safire wrote would have qualified as the most eloquent speech Nixon ever gave — and one of the most poignant by any American president. Thankfully, it never had to be delivered.

Read more:

The dreams and dedication behind our leap to the moon

What the Air and Space Museum’s Kickstarter could mean for the future of space exploration

The false, but persistent, rumor that Neil Armstrong converted to Islam