Neil Armstrong, who made the "giant leap for mankind" as the first human to set foot on the moon, has died. He was 82.
His family said in a statement that the cause of his death last night was "complications resulting from cardiovascular procedures."
He had undergone heart bypass surgery earlier this month in Cincinnati, near where he lived. His recovery had been going well, according to those who spoke with him after the surgery, and his death came as a surprise to many close to him, including his fellow Apollo astronauts.
The family did not say where he died. A quiet, private man, at heart an engineer and crack test pilot, Armstrong made history on July 20th, 1969, as the commander of the Apollo 11 spacecraft on the mission that culminated the Soviet-American space race in the 1960s.
President John F. Kennedy had committed the nation "to achieving the goal, before the decade is out, of landing a man on the Moon and returning him safely to earth."
It was done with more than five months to spare. On that day, Armstrong and his co-pilot, Col. Edwin E Aldrin Jr., known as Buzz, steered their lunar landing craft,
Eagle, to a level, rock-strewn plain near the southwestern shore of the Sea of Tranquility.
It was touch and go the last minute or two, with computer alarms sounding and fuel running low. But they made it.
"Houston, Tranquility Base here," Armstrong radioed to mission control. "The Eagle has landed.""Roger, Tranquility," mission control replied.
"We copy you on the ground. You've got a bunch of guys about to turn blue. We're breathing again. Thanks a lot."
The same could have been said for hundreds of millions of people around the world watching on television. A few hours later, there was Armstrong bundled in a white spacesuit and helmet on the ladder of the landing craft.
Planting his feet on the lunar surface, he said, "That's one small step for man, one giant leap for mankind." (His words would become the subject of a minor historical debate, as to whether he said "man" or an indistinct "a man.")
Soon Aldrin joined Armstrong, bounding like kangaroos in the low lunar gravity, one sixth that of earth's, while the command ship pilot, Michael Collins, remained in orbit about 60 miles overhead, waiting their return.
In all, 12 American astronauts walked on the moon between then and the Apollo 17 mission in 1972.
The Apollo 11 mission capped a tumultuous and consequential decade. The '60s in America had started with such promise, with the election of a youthful president, mixed with the ever-present anxieties of the cold war.
Then it touched greatness in the civil rights movement, only to implode in the years of assassinations and burning city streets and campus riots.
But before it ended, human beings had reached that long-time symbol of the unreachable.
The moonwalk lasted two hours and 19 minutes, long enough to let the astronauts test their footing in the fine and powdery surface - Armstrong noted that his bootprint was less than an inch deep - and set up a television camera and scientific instruments and collect rock samples.
In a statement from the White House, president Barack Obama said, "Neil was among the greatest of American heroes."
"And when Neil stepped foot on the surface of the moon for the first time," the president added, "he delivered a moment of human achievement that will never be forgotten."
Charles F Bolden Jr, the current Nasa administrator, said: "As long as there are history books, Neil Armstrong will be included in them, remembered for taking humankind's first small step on a world beyond our own."
Mr Bolden also noted that in the years after the moonwalk, Armstrong "carried himself with a grace and humility that was an example to us all."
New York Times