Saturday, July 10, 1999 Published at 00:55 GMT 01:55 UK
A silent death
There was no rescue plan for the astronauts
The first astronauts on the moon would have been left to die in silence if they had been stranded by technical failure, according to documents just discovered.
With no rescue mission planned, their communications to Earth would have been switched off and they would have been left to die or commit suicide, the BBC has learned.
President Richard Nixon even had a speech prepared for the watching world if the Apollo XI lunar landing module could not take off from the moon's surface.
A memo found in America's national archives reveals the extent of emergency planning for the mission by Nasa and the US Government.
"These brave men, Neil Armstrong and Buzz Aldrin, know there's no hope for their recovery. But they also know there is hope for mankind in their sacrifice.
"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."
The astronauts insist they were never told of any disaster plans.
The greatest danger to the mission's success came from the lunar landing module. Nobody knew whether it would be able to take off from the moon.
Nasa historian Roger Launis said: "Had they not been able to launch the ascent part of the lunar module they would have been stranded on the surface. There was nothing that was realistic that could be done [for them]."
President Nixon's disaster speech has remained secret for 30 years since the two astronauts first set foot on the moon on 20 July 1969.
And instead of a sombre address Mr Nixon was able to congratulate them on a successful mission.
The two men spent 22 hours on the moon after landing in the Sea of Tranquility. They returned safely home, with Michael Collins, the crew member who did not take part in the moon landing, as heroes.