In 1969, Neil Armstrong became the first man to walk on the Moon and arguably the most famous man in the Universe.
Asked how he felt that day, he replied "very, very small".
He later questioned the value of his legacy as he witnessed the thirst for space exploration become increasingly embroiled in politics and battles for funding, what he called "hucksterism and other attendant nonsense".
Neil Alden Armstrong was born in Ohio on 5 Aug 1930. His father worked for the state government and the family were constantly on the move as he took up new positions.
Armstrong took his first flight aged six with his father and formed a passion for aeronautics that would last all his life. His hero was Charles Lindbergh, and by the age of 16 he could fly before he could drive.
Already a decorated hero after flying Navy fighters in the Korean War, Armstrong became a test pilot for the National Advisory Committee on Aeronautics, Nasa's forerunner.
'One small step...'
Armstrong served as one of an elite group selected to pit technology against nature's limitations.
In 1961, John F Kennedy had promised to have a man on the Moon by the end of the decade.
With the Russians already sending men into space, Americans were determined to fulfil this pledge, so money and support for the Nasa Apollo programme were plentiful.
During an earlier Gemini 8 mission, Armstrong had managed to correct a spinning space capsule and save the lives of himself and his co-pilot. He was famously shy, almost taciturn, but his flying skills made him the natural commander of Apollo 11.
By 1969, the team was ready to fulfil Kennedy's promise. In a spacecraft which had control systems with less than a thousandth of the computing power of a modern laptop, Armstrong and his colleagues Buzz Aldrin and Michael Collins made for the Moon.
People across the world bought television sets for the first time to witness their endeavour, and more than 500 million watched every moment of Apollo 11's arrival on the lunar surface on 20 July.
After steering to avoid large rocks, Armstrong had only 20 seconds of fuel left when he finally landed the module safely between boulders. From inside the capsule, he reported back to an emotional Mission Control in Houston that "the Eagle has landed".
And as he disembarked from his lunar nest, he uttered his carefully prepared phrase, that what he was making was "one small step for man, one giant leap for mankind". He meant to say "a man" but, in the circumstances, most people forgave the fluff.
Instead, they watched awe-struck as, with Aldrin at his side, Armstrong planted an American flag on the Sea of Tranquility.
Back on Earth, the crew received global adulation and honour, and were feted like movie stars wherever they went. But, after the initial publicity round, Armstrong refused to cash in on his singular celebrity.
The man who was revered as a hero by the American public and awarded the Presidential Medal of Freedom for his work, shunned the limelight and the prospective fortune that came with it.
Instead, he lived in the seclusion of his Ohio farmhouse, taught engineering at the University of Cincinnati and later went into business.
He refused to give interviews or sign autographs and disappointed many fans with his requests for privacy. He gave only occasional speeches and his most surprising sortie back into the public arena came in the form of a series of Chrysler commercials.
He once explained, "I don't want to be a living memorial," and while his fellow astronauts trod a precarious path through post-Moon renown - Buzz Aldrin suffering alcoholism and a breakdown - Armstrong remained happy to "bask in obscurity".
Only reluctantly did he join his fellow astronauts for anniversary celebrations of the Moon landing. In 1999, 30 years later, he stood with Aldrin and Collins to receive the Langley medal for aviation from then Vice-President Al Gore.
Marked by a personal humility that meant he scarcely mentioned his own space voyages, Armstrong was nonetheless able to inspire a group of students that met him that day. He told them, "Opportunities will be available to you that you cannot imagine."
No-one has walked on the Moon since 1972 and, for many people today, the idea of landing there again has been overtaken by the prospect of missions to Mars and beyond.
But, the millions around the world who sat glued to their television sets in July 1969 saw their most fantastic dreams made real. For them, the shy man from Ohio opened a fresh frontier and there will be no forgetting Neil Armstrong and his awe-inspiring achievement.